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TUGAS AKHIR
STUDY PERLAKUAN ALKALI DAN FRAKSI VOLUME
SERAT TERHADAP KEKUATAN BENDING, TARIK, DAN
IMPAK KOMPOSIT BERPENGUAT SERAT RAMI
BERMATRIK POLYESTER BQTN 157
Disusun:
LUDI HARTANTO
NIM : D 200 020 185
JURUSAN TEKNIK MESIN FAKULTAS TEKNIK
UNIVERSITAS MUHAMMADIYAH SURAKARTA
JULI 2009
PERNYATAAN KEASLIAN SKRIPSI
Saya menyatakan dengan sesungguhnya bahwa skripsi dengan judul :
“STUDY PERLAKUAN ALKALI DAN FRAKSI VOLUME SERAT
TERHADAP KEKUATAN BENDING, TARIK, DAN IMPAK KOMPOSIT
BERPENGUAT SERAT RAMI BERMATRIK POLYESTER BQTN 157”
Yang dibuat untuk memenuhi sebagai syarat memperoleh derajat sarjana
S1
pada
Jurusan
Teknik
Mesin
Fakultas
Teknik
Universitas
Muhammadiyah Surakarta, sejauh yang saya ketahui bukan merupakan
tiruan atau duplikasi dari skripsi yang sudah dipublikasikan dan pernah
dipakai untuk mendapatkan gelar kesarjanaan di lingkungan Universitas
Muhammadiyah Surakarta atau instansi manapun, kecuali bagian yang
sumber informasinya saya cantumkan sebagaimana mestinya.
Surakarta, 7 Juli 2009
Yang menyatakan,
Ludi Hartanto
ii
HALAMAN PERSETUJUAN
Tugas Akhir berjudul “STUDY PERLAKUAN ALKALI DAN FRAKSI
VOLUME SERAT TERHADAP KEKUATAN BENDING, TARIK, DAN
IMPAK
KOMPOSIT
BERPENGUAT
SERAT
RAMI
BERMATRIK
POLYESTER BQTN 157”, telah disetujui oleh Pembimbing dan diterima
untuk memenuhi sebagai persyaratan memperoleh gelar sarjana S1 pada
Jurusan Teknik Mesin Fakultas Teknik Universitas Muhammadiyah
Surakarta.
Dipersiapkan oleh :
Nama
: LUDI HARTANTO
NIM
: D200 020 185
Disetujui pada
Hari
:............................
Tanggal
:............................
Pembimbing Utama
Pembimbing Pendamping
Ir. Agus Hariyanto, MT
Agus Yulianto, ST,MT
iii
HALAMAN PENGESAHAN
Tugas Akhir berjudul : “STUDY PERLAKUAN ALKALI DAN FRAKSI
VOLUME SERAT TERHADAP KEKUATAN BENDING, TARIK, DAN
IMPAK
KOMPOSIT
BERPENGUAT
SERAT
RAMI
BERMATRIK
POLYESTER BQTN 157”. telah dipertahankan di hadapan Tim Penguji
dan telah dinyatakan sah untuk memenuhi sebagai syarat memperoleh
derajat sarjana S1 pada Jurusan Teknik Mesin Fakultas Teknik
Universitas Muhammadiyah Surakarta.
Dipersiapkan oleh :
Nama
NIM
: LUDI HARTANTO
: D200 020 185
Disahkan pada :
Hari
:.........................
Tanggal :…......................
Tim Penguji :
Ketua
: Ir. Agus Hariyanto, MT
………………….
Anggota 1
: Agus Yulianto, ST, MT
..........................
Anggota 2
: Dr.Kuncoro Diharjo, ST,MT ..........................
Dekan,
Ketua Jurusan,
Ir. H Sri Widodo, MT
Marwan Effendy, ST., MT
iv
v
MOTTO
”Jadikanlah sabaar dan shalat sebagai penolongmu.
Dan sesungguhnya yang demikian itu sungguh berat,
kecuali bagi orang-orang yang khusyu”
(Q.S Al Baqarah : 45)
”karena sesungguhnya sesudah kesulitan itu ada kemudahan,
maka apabila kamu telah selesai dari sesuatu urusan, kerjakanlah
dengan sungguh-sungguh urusan yang lain.
Dan hanya kepada Tuhanmulah hendaknya kamu berharap”
(Q.S Alam Nasyarah : 6-8)
”Yang paling banyak menjatuhkan orang, itu adalah tidak
seimbangnyaantara perkataan dan perbuatan”
(Abdullah Gymnastiar)
”Hidup adalah belajar, kehidupan adalah pelajaran.
Mati adalah misteri, penentuan dan akherat adalah prestasi hidup.
Maka janganlah kamu hidup dengan mimpi-mimpi, tapi hidupkanlah
mimpi-mimpimu”
(Abdullah Gymnastiar)
”Tak ada pengorbanan maka tak ada kemenangan dan tak ada usaha
maka tak akan ada keberhasilan”
(Penulis)
vi
PERSEMBAHAN
Sujud syukurku pada-Mu Illahi Robbi yang senantiasa memberikan
kemudahan bagi hamba-Nya yang mau berusaha. Petunjuk dan
bimbingan-Mu selama hamba menuntut ilmu diperantauan berbuah karya
sederhana ini yang kupersembahkan kepada :
 Agamaku yang telah mengenalkan aku kepada ALLAH SWT serta
Rosul-Nya danmengarahkan jalan dari gelap-gulita menuju terang
benderang, terimakasih ALLAH atas ridhonya hingga saya dapat
menyelesaikan tugas akhir ini, walaupun kadang keluar dari jalan
yang Engkau tetapkan.
(“Engkau yang mendengar do’aku dan mengabulkan jerih payahku”).
 Ayah dan Ibu tercinta, dengan do’a dan kasih sayang tulusnya selalu
senantiasa memberikan kekuatan dalam setiap langkah ananda,
terima kasih atas semua pengorbanan yang tidak ternilai harganya.
 Saudara-saudaraku yang selalu memberikanku do’a, inpirasi maupun
dukungan kepadaku.
 Seseorang yang kelak kan menjadi pendampingku, yang telah
memberikanku inspirasi, motivasi, dan kesetiaan.
 Almamater Fakultas Teknik UMS.
vii
ABSTRAKSI
STUDY PERLAKUAN ALKALI DAN FRAKSI VOLUME SERAT
TERHADAP KEKUATAN BENDING, TARIK, DAN IMPAK KOMPOSIT
BERPENGUAT SERAT RAMI BERMATRIK POLYESTER BQTN 157
Ludi Hartanto., Agus Hariyanto, Agus Yulianto.
Teknik Mesin Universitas Muhammadiyah Surakarta
JL. A. Yani Pabelan Kartasura Tromol Pos I Sukoharjo
ABSTRAKSI
Tujuan dari penelitian ini adalah untuk mengetahui kekuatan
bending,tarik dan impak yang optimal dari komposit serat rami pada fraksi
volume 20%, 30%, 40%, 50% dengan variasi ketebalan 1mm hingga
5mm,dengan perlakuan alkali serta mengetahui jenis patahan dengan
pengamatan makro pada specimen yang memiliki harga optimal dari
pengujian bending,tarik dan impak.
Pada penelitian ini bahan yang dipergunakan adalah serat ramie
yang disusunan acak dengan fraksi volume 20%, 30%, 40%, 50%, dengan
variasi tebal 1mm hingga 5mm, menggunakan Polyester BQTN 157
sebagai matriknya. Pembuatan dengan cara press mold, pengujian
bending yang dilakukan dengan acuan standar ASTM D 790-02,tarik
dengan standart ASTM 638-02 dan Impak charpy dengan acuan standart
ASTM D 256-00.
Hasil pengujian didapat pengaruh alkali 2,4,6,dan 8 jam pada
fraksi volume 20%, 30%, 40%, 50%, dengan variasi tebal 1mm hingga
5mm. Pada pengujian bending optimal rata-rata pada vf 40% dengan
ketebalan 3mm dan paling optimal pada alkali 2 jam,Pada uji tarik optimal
pada vf 50% ketebalan 5mm dan paling optimal pada alkali 2 jam,dan
Pada uji Impak optimal rata-rata pada vf 40% dan 50% pada ketebalan
5mm dan paling optimal pada vf 50% alkali 6 jam. Pengamatan struktur
makro didapatkan jenis patahan broken fiber.
Kata kunci : Serat Rami, Polyester, Kekuatan, Alkali.
viii
KATA PENGANTAR
Assalamu’alaikum Wr. Wb.
Syukur Alhamdulillah, penulis panjatkan kehadirat Allah SWT atas
berkah dan rahmat-Nya sehingga penyusun laporan penelitian ini dapat
terselesaikan.
Tugas Akhir berjudul ”STUDY PERLAKUAN ALKALI DAN
FRAKSI VOLUME SERAT TERHADAP KEKUATAN BENDING, TARIK,
DAN IMPAK KOMPOSIT BERPENGUAT SERAT RAMI BERMATRIK
POLYESTER BQTN 157”, dapat terselesaikan atas dukungan dari pihak.
Untuk itu pada kesempatan ini, penulis dengan segala ketulusan dan
keikhlasan hati ingin menyampaikan rasa terima kasih dan penghargaan
yang sebesar-besarnya kepada :
1. Bapak Ir. H. Sri Widodo, MT, selaku Dekan Fakultas Teknik Universitas
Muhammadiyah Surakarta.
2. Bapak Marwan Effendy, ST, MT, selaku Ketua Jurusan Teknik Mesin
Fakultas Teknik Universitas Muhammadiyah Surakarta.
3. Bapak Ir. Agus Hariyanto, MT selaku Dosen Pembimbing I yang telah
membimbing, mengarahkan, memberikan petunjuk dalam penyusunan
Tugas Akhir ini dengan sangat perhatian, baik, sabar dan ramah.
4. Bapak Agus Yulianto, ST, MT, selaku Dosen Pembimbing II yang telah
membimbing, mengarahkan, memberikan petunjuk dalam penyusunan
Tugas Akhir ini dengan sangat perhatian, baik, sabar dan ramah.
5. Dosen Jurusan Teknik Mesin Universitas Muhammadiyah Surakarta
yang telah memberikan ilmu pengetahuan kepada penulis selama
mengikuti kegiatan kuliah.
6. Bapak dan Ibu tercinta yang setiap malam selalu mendoakan,
memberikan semangat dan dorongan, serta terima kasih atas semua
nasehat, bimbingan, dan pengorbanan mu selama ini sehingga penulis
ix
terpacu untuk menyelesaikan skripsi ini. Semua do’a dan kasih sayang
yang tulus ini akan selalu mengiringi langkahku”
7. Kakak dan adikku yang slalu memberikan semangat,bantuan dan
pengertiannya selama ini.
8. Teman-teman kontrakan Utopia, terima kasih atas segala suka duka
yang mewarnai sebagian hari-hari penulis, semoga persaudaraan ini
bisa berlangsung lebih lama lagi. Amien.
Penulis menyadari bahwa laporan ini masih jauh dari sempurna,
oleh karena itu kritik dan saran yang bersifat membangun dari pembaca
akan penulis terima dengan senang hati.
Wassalamu’alaikum Wr. Wb
Surakarta, 7 Juli 2009
Penulis
x
DAFTAR ISI
HALAMAN JUDUL............................................................................... i
PERNYATAAN KEASLIAN SKRIPSI.....................................................ii
HALAMAN PERSETUJUAN .............................................................. iii
HALAMAN PENGESAHAN ................................................................. iv
LEMBAR SOAL TUGAS AKHIR...............................................................v
MOTTO ................... ........................................................................... vi
ABSTRAKSI.................... ...................................................................... vii
KATA PENGANTAR............................................................................ viii
DAFTAR ISI .............. ........................................................................... x
DAFTAR GAMBAR ....... ...................................................................... xiii
DAFTAR TABEL ............ ................................................................. xvii
DAFTAR NOTASI............................................................................... xviii
DAFTAR LAMPIRAN.......................................................................... xix
BAB I PENDAHULUAN
1.1. Latar Belakang Masalah .................................................. 1
1.2. Tujuan Penelitian ............................................................. 2
1.3. Manfaat Penelitian .................................................. 3
1.4. Perumusan masalah........................................................... 4
1.5. Batasan Masalah ................................................................ 4
1.6. Sistem Penulisan Laporan .................................................. 5
BAB II TINJAUAN PUSTAKA DAN LANDASAN TEORI
2.1. Kajian Pustaka ................................................................. 7
2.2. Landasan Teori ............................................................... 9
2.2.1. Definisi Komposit ................................................... 9
2.2.2. Klasifikasi
Material
komposit
berdasarkan
bentuk
komponen strukturalnya ....................................... 11
2.2.3. Unsur-unsur Utama Pembentuk komposit FRP ... 15
2.2.4. Aspek Geometri ................................................... 22
2.2.5. Perpatahan (Frature) ........................................... 33
xi
BAB III METODOLOGI PENELITIAN
3.1. Persiapan Bahan dan Alat.................................................................. 35
3.1.1. Penyiapan Bahan .................................................... 35
3.1.2. Penyiapan Alat ........................................................ 37
3.2. Diagram Alir..................................................................... . . 40
3.2.1. Survey Lapangan dan study literature .................... 41
3.2.2. Penyiapan Bahan .................................................. 41
3.2.3. Pembuatan Komposit.............................................. 41
3.2.4. Pengujian Komposit ................................................ 45
BAB IV DATA HASIL PENELITIAN DAN PEMBAHASAN
4.1. Pengujian Bending ………………………………………..... 53
4.1.1. Data Hasil Pengujian Bending Alkali 2 jam ……... 53
4.1.1.1. Pembahasan Pengujian bending Alkali 2 jam.. 58
4.1.2. Data Hasil Pengujian Bending Alkali 4 jam …….. 60
4.1.2.1. Pembahasan Pengujian bending Alkali 4 jam... 65
4.1.3. Data Hasil Pengujian Bending Alkali 6 jam……... 67
4.1.3.1. Pembahasan Pengujian bending Alkali 6 jam.. 72
4.1.4. Data Hasil Pengujian Bending Alkali 8 jam …….. 74
4.1.4.1. Pembahasan Pengujian bending Alkali 8 jam... 79
4.2. Pengujian Tarik …………………………………………….. 81
4.2.1. Data Hasil Pengujian Tarik Alkali 2 jam ………… 81
4.2.1.1. Pembahasan Pengujian Tarik Alkali 2 jam …… 83
4.2.2. Data Hasil Pengujian Tarik Alkali 4 jam ………... 84
4.2.2.1. Pembahasan Pengujian Tarik Alkali 4 jam …… 86
4.2.3. Data Hasil Pengujian Tarik Alkali 6 jam…………. 87
4.2.3.1. Pembahasan Pengujian Tarik Alkali 6 jam……. 89
4.2.4. Data Hasil Pengujian Tarik Alkali 8 jam ………… 90
4.2.4.1. Pembahasan Pengujian Tarik Alkali 8 jam……. 92
4.3. Pengujian IMPAK …………………………………………... 93
4.3.1. Data Hasil Pengujian Impak Alkali 2 jam ……… 93
4.3.1.1. Pembahasan Pengujian Impak Alkali 2 jam .... 95
4.3.2. Data Hasil Pengujian Impak Alkali 4 jam …….... 96
xii
4.3.3. Data Hasil Pengujian Impak Alkali 6 jam ……...... 99
4.3.3.1. Pembahasan Pengujian Impak Alkali 6 jam..... 101
4.3.4. Data Hasil Pengujian Impak Alkali 8 jam …….... 102
4.4. Pengamatan Struktur makro ………………………………. 105
4.4.1. Pembahasan Foto Makro ……………………….... 107
BAB V KESIMPULAN DAN SARAN
5.1.
Kesimpulan...................................................................... 109
5.2. Saran................................................................................ 111
DAFTAR PUSTAKA
LAMPIRAN
xiii
DAFTAR GAMBAR
Gambar 2.1 Continous fiber composite .............................................. 11
Gambar 2.2 Woven fiber composite ................................................... 13
Gambar 2.3 Chopped fiber composite ................................................. 14
Gambar 2.4 Hybrid composite ........................................................... 15
Gambar 2.5 Particulate Composite ...................................................... 16
Gambar 2.6 Laminated Composites .................................................... 17
Gambar 2.7 Skema Uji Densitas (Goerge, N B and Brian R. 2003). . 29
Gambar 2.8 Penampang Uji bending (Standart ASTM D 790-02)….. 26
Gambar 2.9 Spesimen dan peralatan uji Impak.................................. 63
Gambar 3.1 Serat rami sebelum diacak ............................................. 85
Gambar 3.2 serat rami setelah diacak ............................................... 86
Gambar 3.3 Resin Polyester Yucalac tipe 157 dan katalis ................. 86
Gambar 3.4 Larutan NaOH................................................................. 87
Gambar 3.5 Timbangan Digital ......................................................... 87
Gambar 3.6. wood moisture meter ..................................................... 88
Gambar 3.7 Cetakan untuk benda uji ................................................. 88
Gambar 3.8. Alat Pengepres Cetakan ................................................ 89
Gambar 3.9 Alat bantu lain ................................................................. 89
Gambar 3.10. Diagram alir penelitian ..................................................40
Gambar 3.11 Hasil cetakan komposit serat Ramie dengan matrik
polyester ..................................................................... 90
Gambar 3.12 Spesimen uji tarik komposit serat rami. ....................... 91
Gambar 3.13 Spesimen uji bending komposit serat ramie ................. 91
Gambar 3.14 Spesimen uji Impak komposit serat ramie ................... 92
Gambar 3.15 Dimensi pengujian bending Standar ASTM D 790-02. 46
Gambar 3.16. Mesin Pengujian Bending ............................................ 93
Gambar 3.17 Mesin pengujian Impak charpy .................................... 94
Gambar 3.18 Dimensi Impak ASTM D 5942-96 ................................ 94
Gambar 3.19 Dimensi benda pengujian tarik...................................... 94
Gambar 3.20 Mesin pengujian tarik ................................................... 95
xiv
Gambar 4.1 Grafik hubungan momen bending rata-rata dengan fraksi
volume terhadap tebal komposit …………………………. 55
Gambar 4.2 Grafik hubungan tegangan bending rata-rata dengan fraksi
volume terhadap tebal komposit ……………………….. 56
Gambar 4.3 Grafik hubungan defleksi bending rata-rata dengan fraksi
volume terhadap tebal komposit ………………………… 56
Gambar 4.4 Grafik hubungan modulus elastisitas bending rata-rata
dengan fraksi volume terhadap tebal komposit………. 57
Gambar 4.5 Grafik hubungan kekakuan bending rata-rata dengan fraksi
volume terhadap tebal komposit ………………………. 57
volume terhadap tebal komposit ..................................... 62
volume terhadap tebal komposit……………………….. 63
volume terhadap tebal komposit……………………….. 63
volume terhadap tebal komposit………………………. 64
volume terhadap tebal komposit……………………… 70
xv
dengan fraksi volume terhadap tebal komposit…….. 78
Gambar 4.21 Grafik hubungan modulus elastisitas tarik rata-rata dengan
fraksi volume terhadap tebal komposit………………. 82
Gambar 4.22 Grafik hubungan kekuatan tarik rata-rata dengan fraksi
fraksi volume terhadap tebal komposit……………… 85
volume terhadap tebal komposit………………………85
Gambar 4.29 Grafik hubungan Harga Impak rata-rata dengan fraksi
Gambar 4.30 Grafik Hubungan Energi Serap Impak Rata-rata dengan
Fraksi Volume Terhadap Tebal Komposit…………… 94
volume terhadap tebal komposit…………………….. 97
xvi
Gambar 4.32 Grafik Hubungan Energi Serap ImpakRata-rata dengan
Fraksi Volume Terhadap Tebal Komposit……………97
Gambar 4.34 Grafik Hubungan Energi Serap ImpakRata-rata dengan
Gambar 4.36 Grafik Hubungan Energi Serap Impak Rata-rata dengan
Gambar 4.37 Contoh Patahan Spesimen pada Uji Bending dengan
perbedaan waktu alkali………………………………... 105
Gambar 4.38 Contoh Patahan spesimen pada Uji Impak dengan
perbedaan waktu alkali………………………………… 106
Gambar 4.39 Contoh Patahan spesimen pada Uji Tarik dengan
perbedaan waktu alkali………………………………… 107
xvii
DAFTAR TABEL
Tabel 2.1 Sifat mekanik dari beberapa jenis serat....................................17
Tabel 4.1 Data hasil pengujian bending rata-rata pada tebal 1mm.........53
Tabel 4.2 Data hasil pengujian bending rata-rata pada tebal 2mm.........53
Tabel 4.3 Data hasil pengujian bending rata-rata pada tebal 3mm…….54
Tabel 4.7 Data hasil pengujian bending rata-rata pada tebal 2mm……..60
Tabel 4.10 Data hasil pengujian bending rata-rata pada tebal 5mm……62
Tabel 4.21 Hasil Data Pengujian Tarik Alkali 2 Jam……………………..81
Tabel 4.25 Hasil Data Pengujian Impak Alkali 2 Jam…………………..93
xviii
DAFTAR NOTASI
A
= Luas Penampang
E
= Modulus Elastisitas
Eserap
= Energi Yang Terserap
Is
= Kekuatan Impak
L
= Jarak antara tumpuan
P
= Beban Tekan
Vc
= Volume Komposit
Vf
= Fraksi Volume
mu
= Berat Specimen Di udara
ma
= Berat Specimen Dalam air
ρair
= Densitas air
σ
= Tegangan tarik
ΔL
= Deformasi/pemanjangan
xix
DAFTAR LAMPIRAN
Lampiran 1. Annual Book of ASTM
Lampiran 2. Data hasil pengujian bending,tarik,dan Impak
Lampiran 3. Analisis perhitungan pengujian bending,tarik,dan Impak
Lampiran 4. Tabel mechanical properties fiber dan resin
Lampiran 5. Uji Density serat rami dengan kadar air 10%
Lampiran 6. Analisis perhitungan fraksi volume
Lampiran 7. Konversi Satuan
Lampiran 8. Gambar mesin pengolahan serat rami
xx
1
BAB I
PENDAHULUAN
1.1. Latar Belakang Masalah
Penggunaan material komposit dengan filler serat alam mulai
banyak dikenal dalam industri manufaktur. Material yang ramah
lingkungan, mampu didaur ulang, serta mampu dihancurkan sendiri
oleh alam merupakan tuntutan teknologi sekarang ini. Salah satu
material yang diharapkan mampu memenuhi hal tersebut adalah
material komposit dengan material pengisi (filler) serat alam.
Keunggulan yang dimiliki oleh serat alam antara lain : non-abbrasive,
densitas rendah, harga lebih murah, ramah lingkungan, dan tidak
membahayakan bagi kesehatan. Penggunaan serat alam sebagai
filler dalam komposit tersebut terutama untuk lebih menurunkan biaya
bahan baku dan peningkatan nilai salah satu produk pertanian. (Fajar,
2008).
Serat alam dapat menjadi filler dalam komposit karena
kandungan selulosa beberapa serat alam yang memiliki selulosa
antara lain kenaf, cantalu, tebu, jagung, abaca, padi, ramie dan lainlain. Tanaman ramie ( Boehmeria Nivea ) adalah sumber bahan baku
serat tekstil alam tumbuh-tumbuhan, sebagaimana halnya dengan
serat kapas, linen (flax) dan sejenisnya. Sejak jaman dahulu rami
digunakan untuk bahan pembuat pakaian dan juga sebagai baju
1
2
perang karena keuletan rami mampu menahan sabetan pedang,
bahkan sekarang serat rami diteliti oleh pihak militer untuk bahan
pembuatan baju anti peluru (Jamasri, 2008).
Dalam penelitian ini menggunakan filler serat ramie, jenis
pengikat yang digunakan adalah resin polyester. Resin polyester
merupakan salah satu resin termoset yang mudah diperoleh dan
digunakan masyarakat umum maupun industri skala kecil maupun
besar. Resin polyester ini juga mempunyai kemampuan berikatan
dengan serat alam tanpa menimbulkan reaksi dan gas, oleh karena itu
resin polyester digunakan dalam penelitian ini.
Untuk meningkatkan fungsi guna dari serat ramie yang biasa
digunakan untuk bahan tekstil dan kerajinan rakyat menjadi material
teknik, maka perlu diteliti dan dikembangkan sebagai bahan komposit
yang sesuai sifat fisis dan mekanisnya, sehingga akan tercipta bahan
komposit baru.
1.2. Tujuan Penelitian
Tujuan penelitian ini adalah :
1. Mengetahui kekuatan bending yang paling optimal dari komposit
serat ramie pada fraksi volume serat 20%, 30%, 40%, dan 50%
dengan variasi tebal komposit 1 mm, 2 mm, 3 mm, 4 mm, dan 5
mm, dan perlakuan alkali 2 jam , 4 jam , 6 jam , 8 jam ,bermatrik
resin poliester tipe BQTN 157.
3
2. Mengetahui kekuatan impak yang paling optimal dari komposit
serat ramie pada fraksi volume serat 20%, 30%, 40%, dan 50%
dengan variasi tebal komposit 1 mm, 2 mm, 3 mm, 4 mm, dan 5
mm, dan perlakuan alkali 2 jam , 4 jam , 6 jam , 8 jam ,bermatrik
resin poliester tipe BQTN 157.
3. Mengetahui kekuatan tarik yang paling optimal dari komposit serat
ramie pada fraksi volume serat 20%, 30%, 40%, dan 50% dengan
variasi tebal komposit 1 mm, 2 mm ,3 mm, 4 mm, dan 5 mm, dan
perlakuan alkali 2 jam, 4 jam, 6 jam, 8 jam ,bermatrik resin
poliester tipe BQTN 157.
4.
Mengetahui jenis patahan pengujian bending , impak dan tarik
dengan foto makro.
1.3. Manfaat Penelitian
Manfat dari penelitian ini adalah sebagai berikut:
1. Bagi peneliti adalah untuk menambah pengetahuan, wawasan dan
pengalaman tentang penelitian material komposit.
2. Bagi akademik, penelitian ini dapat digunakan sebagai referensi
tambahan untuk penelitian tentang komposit serat alam (natural
fibrous composite).
3. Bagi industry dapat digunakan sebagai acua atau pedoman dalam
pembuatan komposit yang terbuat dari serat alam, khusunya serat
4
ramie sehingga meningkatkan nilai jual serat ramie sekaligus
meningkatkan pendapatan masyarakat khususnya petani ramie.
1.4. Rumusan Masalah
Komposit Penguatan Serat (Fibrous Composite) menggunakan
serat ramie yang disusun secara acak dan matrik resin polyester
sebagai pembentuk material komposit, dengan adanya penambahan
fraksi volume dan penambahan variasi tebal, serta perlakuan alkali
bagaimanakah performasi dari bahan serat komposit ini? Bagaimana
jenis patahan specimen hasil pengujian bendin, impak dan tarik?
Permasalahan-permasalahan tersebut akan menjadi topik utama
penelitian ini.
1.5. Pembatasan Masalah
Agar masalah tidak melebar dari pembahasan utama, maka
permasalahan hanya dibatasi pada:
1. Pengujian komposit pada serat ramie yang disusun acak dengan
fraksi volume serat 20%, 30%, 40%, dan 50% dan dengan variasi
tebal komposit 1mm, 2mm, 3mm, 4mm, dan5 mm, dan perlakuan
alkali 2 jam, 4 jam, 6 jam, 8 jam dengan matrik resin polyester tipe
BQTN 157.
2. Jenis komposit yang dijadikan sebagai bahan penelitian pada
tugas akhir ini adalah jenis fibrous komposit (komposit serat).
5
3. Pengujian komposit berupa uji kekuatan bending (Standart ASTM
D 790-02), uji impak (Standart ASTM D 256-00) dan uji tarik
(Standart ASTM D 638-02).
4. Benda uji dibuat dengan cara press mold dan menggunakan kaca
sebagai cetakan.
5. Serat dengan perlakuan Alkali 2 jam, 4 jam, 6 jam, dan 8 jam.
1.6. Sistematika Penulisan Laporan
Laporan penulisan Tugas Akhir ini disusun dengan sistematika
sebagai berikut:
BAB I PENDAHULUAN
Berisi tentang latar belakang, tujuan penelitian, manfaat
penelitian,
perumusan
masalah,
pembatasan
masalah,
dan
sistematika penulisan laporan.
BAB II TINJAUAN PUSTAKA DAN LANDASAN TEORI
Bab ini berisi tentang tinjauan pustaka dan dasar teori.
Tinjauan pustaka memuat uraian sistematis tentang hasil-hasil riset
yang didapat oleh peneliti terdahulu dan berhubungan dengan
penelitian ini. Dasar teori ini dijadikan sebagai penuntun untuk
memecahkan masalah yang berbentuk uraian kualitatif atau model
matematis.
6
BAB III PELAKSANAAN PENGUJIAN
Bab ini berisi tentang diagram alur penelitian, penyiapan benda
uji, pembuatan benda uji, serta pengujian mekanis komposit.
BAB IV HASIL PENELITIAN DAN PEMBAHASAN
Bab ini berisi tentang hasil dan pembahasan pengujian
bending, impak, dan tarik dan pengamatan foto makro, serta analisis
perhitungan.
BAB V KESIMPULAN DAN SARAN
Bab ini berisi tentang kesimpulan dan saran.
DAFTAR PUSTAKA
LAMPIRAN
7
BAB II
LANDASAN TEORI
2.1. Tinjauan pustaka
Nurkholis (2008), meneliti kekuatan tarik dan impak komposit
berpenguat serat rami dengan perlakuan alkali (NaOH) selama 2, 4, 6
dan 8 jam dengan fraksi volume serat 10% dan 90% bermatrik poliester
BQTN 157, pembuatan komposit dilakukan dengan pencetakan
metode hand lay up menggunakan kaca sebagai cetakannya dan
perlakuan post cure 600 selama 4jam, diperoleh kekuatan tarik tertinggi
dimiliki oleh komposit serat rami dengan perlakuan alkali 8 jam yaitu
sebesar 41,9 MPa dengan modulus elastisitas 2743,15 MPa pada
perlakuan alkali 2jam, harga impak tertinggi terjadi pada perlakuan
alkali 4 jam yaitu sebesar 0,0725 J/mm2.
Fajar (2008), meneliti kekuatan bending dan impak komposit
serat rami susun acak dengan matrik polyester BQTN 157 tanpa
perlakuan alkali, pembuatan komposit dilakukan dengan metode pres
mold. Dari hasil pengujian diperoleh sebagai berikut : pengujian
bending didapat nilai tegangan bending rata-rata tertinggi dimiliki oleh
komposit dengan Vf 50% pada tebal 5mm sebesar 95,33 MPa dan
terendah pada komposit dengan Vf 20% pada tebal 4mm sebesar
44,52 MPa, modulus elastisitas bending rata-rata tertinggi dimiliki oleh
komposit dengan Vf 40% pada tebal 1mm sebesar 5462,93 MPa dan
7
8
terendah pada komposit dengan Vf 20% pada tebal 4mm. Untuk harga
impak rata-rata tertinggi dimiliki oleh komposit dengan Vf 20% pada
tebal 1mm sebesar 0,119 J/mm2 dan terendah pada komposit dengan
Vf 40% pada tebal 5mm sebesar 0,024 J/mm2.
Junaedi (2008), menguji kekuatan tarik dan impak komposit
berpenguat serat rami dengan variasi panjang serat 25mm, 50mm dan
100mm dengan fraksi volume 90% matrik poliester BQTN 157 dan 10%
serat rami, pembuatan komposit dengan cara prees mold. Diperoleh
kekuatan tarik tertinggi pada komposit dengan panjang serat 100mm
yaitu 52,483 MPa, dengan modulus elastisitas 5577,213 MPa, harga
impak tertinggi dimiliki oleh komposit dengan panjang serat 50mm yaitu
0,087 J/mm2.
Ditinjau dari penelitian yang telah dilakukan diatas, maka dapat
disimpulkan bahwa kekuatan bending, impak dan tarik dipengaruhi oleh
adanya variasi fraksi volume (Vf) semakin tinggi fraksi volumenya maka
semakin tinggi pula kekuatannya. Maka dari itu penulis mencoba
meneliti komposit berpenguat serat rami acak dengan perlakuan alkali
2jam, 4jam, 6jam dan 8jam, dengan variasi fraksi volume serat (Vf)
20%, 30%, 40% dan 50% bermatrik polyester BQTN 157, terhadap
variasi tebal komposit 1mm, 2mm, 3mm, 4mm dan 5mm.
9
2.2. Landasan Teori
2.2.1. Definisi Komposit
Kata komposit berasal dari kata “to compose” yang berarti
menyusun atau menggabung. Secara sederhana bahan komposit
berarti bahan gabungan dari dua atau lebih bahan yang berlainan. Jadi
komposit adalah suatu bahan yang merupakan gabungan atau
campuran dari dua material atau lebih pada skala makroskopis untuk
membentuk material ketiga yang lebih bermanfaat. Komposit dan alloy
memiliki perbedaan dari cara penggabungannya yaitu apabila komposit
digabung secara makroskopis sehingga masih kelihatan serat maupun
matriknya (komposit serat) sedangkan pada alloy / paduan digabung
secara
mikroskopis
sehingga
tidak
kelihatan
lagi
unsur-unsur
pendukungnya ( Jones, 1975).
Sesungguhnya ribuan tahun lalu material komposit telah
dipergunakan dengan memanfaatkannya serat alam sebagai penguat.
Dinding bangunan tua di Mesir yang telah berumur lebih dari 3000
tahun ternyata terbuat dari tanah liat yang diperkuat jerami (Jamasri,
2008). Seorang petani memperkuat tanah liat dengan jerami, para
pengrajin besi membuat pedang secara berlapis dan beton bertulang
merupakan beberapa jenis komposit yang sudah lama kita kenal.
Komposit dibentuk dari dua jenis material yang berbeda, yaitu:
1. Penguat (reinforcement), yang mempunyai sifat kurang ductile
tetapi lebih rigid serta lebih kuat.
10
2. Matrik, umumnya lebih ductile tetapi mempunyai kekuatan dan
rigiditas yang lebih rendah.
Pada material komposit sifat unsur pendukungnya masih terlihat
dengan jelas, sedangkan pada alloy / paduan sudah tidak kelihatan lagi
unsur-unsur pendukungnya. Salah satu keunggulan dari material
komposit
bila
dibandingkan
dengan
material
lainnya
adalah
penggabungan unsur-unsur yang unggul dari masing-masing unsur
pembentuknya tersebut. Sifat material hasil penggabungan ini
diharapkan dapat saling melengkapi kelemahan-kelemahan yang ada
pada masing-masing material penyusunnya. Sifat-sifat yang dapat
diperbaharui (Jones,1975) antara lain :
Sifat-sifat yang dapat diperbaiki antara lain:
a. kekuatan (Strength)
b. kekakuan (Stiffness)
c. ketahanan korosi (Corrosion resistance)
d. ketahanan gesek/aus (Wear resistance)
e. berat (Weight)
f. ketahanan lelah (Fatigue life)
g. Meningkatkan konduktivitas panas
h. Tahan lama
Secara alami kemampuan tersebut diatas tidak ada semua pada
waktu yang bersamaan (Jones, 1975). Sekarang ini perkembangan
teknologi komposit mulai berkembang dengan pesat. Komposit
11
sekarang ini digunakan dalam berbagai variasi komponen antara lain
untuk otomotif, pesawat terbang, pesawat luar angkasa, kapal dan alatalat olah raga seperti ski, golf, raket tenis dan lain-lain.
2.2.2. Klasifikasi
Material
Komposit
Berdasarkan
bentuk
komponen strukturalnya
Secara garis besar komposit diklasifikasikan menjadi tiga
macam (Jones, 1975), yaitu:
1. Komposit serat (Fibrous Composites)
2. Komposit partikel (Particulate Composites)
3. Komposit lapis (Laminates Composites)
2.2.2.1. Komposit serat (Fibrous Composites)
Komposit serat adalah komposit yang terdiri dari fiber
dalam matriks. Secara alami serat yang panjang mempunyai
kekuatan yang lebih dibanding serat yang berbentuk curah
(bulk). Merupakan jenis komposit yang hanya terdiri dari satu
lamina atau satu lapisan yang menggunakan penguat berupa
serat / fiber. Fiber yang digunakan bisa berupa fibers glass,
carbon fibers, aramid fibers (poly aramide), dan sebagainya.
Fiber ini bisa disusun secara acak maupun dengan orientasi
tertentu bahkan bisa juga dalam bentuk yang lebih kompleks
seperti anyaman. Serat merupakan material yang mempunyai
perbandingan panjang terhadap diameter sangat tinggi serta
12
diameternya
berukuran
mendekati
kristal.
serat
juga
mempunyai kekuatan dan kekakuan terhadap densitas yang
besar (Jones, 1975).
Kebutuhan akan penempatan serat dan arah serat yang
berbeda menjadikan komposit diperkuat serat dibedakan lagi
menjadi beberapa bagian diantaranya:
1) Continous fiber composite (komposit diperkuat dengan
serat kontinue).
Gambar 2.1. Continous fiber composite (Gibson, 1994)
2) Woven fiber composite (komposit diperkuat dengan serat
anyaman).
Gambar 2.2. Woven fiber composite (Gibson, 1994)
3) Chopped fiber composite (komposit diperkuat serat
pendek/acak)
13
Gambar 2.3. Chopped fiber composite (Gibson, 1994)
4) Hybrid composite (komposit diperkuat serat kontinyu
dan serat acak).
Gambar 2.4. Hybrid composite (Gibson, 1994)
2.2.2.2. Komposit Partikel (Particulate Composites)
Merupakan komposit yang menggunakan partikel serbuk
sebagai penguatnya
dan terdistribusi secara merata dalam
matriknya.
Gambar 2.5. Particulate Composite
(www.kemahasiswaan.its.ac.id)
Komposit ini biasanya mempunyai bahan penguat yang
dimensinya kurang lebih sama, seperti bulat serpih, balok,
serta bentuk-bentuk lainnya yang memiliki sumbu hampir
14
sama, yang kerap disebut partikel, dan bisa terbuat dari satu
atau lebih material yang dibenamkan dalam suatu matriks
dengan material yang berbeda. Partikelnya bisa logam atau
non logam, seperti halnya matriks. Selain itu adapula polimer
yang mengandung partikel yang hanya dimaksudkan untuk
memperbesar volume material dan bukan untuk kepentingan
sebagai bahan penguat (Jones, 1975).
2.2.2.3. Komposit Lapis (Laminates Composites)
Merupakan jenis komposit terdiri dari dua lapis atau lebih
yang digabung menjadi satu dan setiap lapisnya memiliki
karakteristik sifat sendiri.
Gambar 2.6. Laminated Composites
(www.kemahasiswaan.its.ac.id)
Komposit ini terdiri dari bermacam-macam lapisan
material dalam satu matriks. Bentuk nyata dari komposit
lamina adalah:( Jones, 1999)
1. Bimetal
Bimetal adalah lapis dari dua buah logam yang mempunyai
koefisien ekspansi thermal yang berbeda. Bimetal akan
15
melengkung seiring dengan berubahnya suhu sesuai
dengan perancangan, sehingga jenis ini sangat cocok
untuk alat ukur suhu.
2. Pelapisan logam
Pelapisan logam yang satu dengan yang lain dilakukan
untuk mendapatkan sifat terbaik dari keduanya.
3. Kaca yang dilapisi
Konsep ini sama dengan pelapisan logam. Kaca yang
dilapisi akan lebih tahan terhadap cuaca.
4. Komposit lapis serat
Dalam hal ini lapisan dibentuk dari komposit serat dan
disusun dalam berbagai orientasi serat. Komposit jenis ini
biasa digunakan untuk panel sayap pesawat dan badan
pesawat.
2.2.3. Unsur-unsur Utama Pembentuk Komposit FRP
FRP (Fiber Reinforced Plastics) mempunyai dua
unsur bahan yaitu serat (fiber) dan bahan pengikat serat
yang disebut dengan matriks. Unsur utama dari bahan
komposit adalah serat, serat inilah yang menentukan
karakteristik suatu bahan seperti kekuatan, keuletan,
kekakuan dan sifat mekanik yang lain. Serat menahan
sebagian besar gaya yang bekerja pada material komposit,
16
sedangkan
matriks
mengikat
serat,
melindungi
dan
meneruskan gaya antar serat (Van Vlack, 2005)
Secara
prinsip,
komposit
dapat
tersusun
dari
berbagai kombinasi dua atau lebih bahan, baik bahan
logam, bahan organik, maupun bahan non organik. Namun
demikian bentuk dari unsur-unsur pokok bahan komposit
adalah fibers, particles, leminae or layers, flakes fillers and
matrix. Matrik sering disebut unsur pokok body, karena
sebagian besar terdiri dari matriks yang melengkapi
komposit (Van vlack, 2005).
2.2.3.1. Serat
Serat atau fiber dalam bahan komposit berperan
sebagai bagian utama yang menahan beban, sehingga
besar kecilnya kekuatan bahan komposit sangat tergantung
dari kekuatan serat pembentuknya. Semakin kecil bahan
(diameter serat mendekati ukuran kristal) maka semakin
kuat bahan tersebut, karena minimnya cacat pada material
(Triyono,& Diharjo k, 2000).
Selain itu serat (fiber) juga merupakan unsur yang
terpenting, karena seratlah nantinya yang akan menentukan
sifat mekanik komposit tersebut seperti kekakuan, keuletan,
kekuatan dsb. Fungsi utama dari serat adalah:
17

Sebagai pembawa beban. Dalam struktur komposit 70% 90% beban dibawa oleh serat.

Memberikan sifat kekakuan, kekuatan, stabilitas panas dan
sifat-sifat lain dalam komposit.

Memberikan
insulasi
kelistrikan
(konduktivitas)
pada
komposit, tetapi ini tergantung dari serat yang digunakan.
Tabel 2.1. Sifat mekanik dari beberapa jenis serat.( Dieter H. Mueller )
Cotton
Flax
Jute
Kenaf
E-Glass
Ramie
Sisal
Diameter
mm
-
11–33
200
200
5–25
40–80
50–
200
Panjang
mm
10–60
10–40
1–5
2–6
-
60–260
1–5
Kekuatan tarik
MPa
930
1800
400–
1050
GPa
26.5
53.0
69.0–
73.0
61.5
Massa jenis
g/cm3
345–
1035
27.6–
45.0
1.43–
1.52
393–
773
Modulus
elastisitas
330–
585
4.5–
12.6
1.5–
1.54
1.5
2.5
1.5–1.6
1.6
2.5–3.0
3.6–3.8
511–
635
9.4–
15.8
1.16–
1.5
2.0–
2.5
Regangan
maksimum
Spesifik
kekuatan tarik
Spesifik
kekakuan
1.44–
1.50
1.5–
2.7–3.2
1.8
%
7.0–8.0
km
39.2
73.8
52.5
63.2
73.4
71.4
43.2
km
0.85
3.21
1.80
3.60
2.98
4.18
1.07
2.2.3.1.
Matrik
Menurut Gibson (1994), bahwa matrik dalam struktur
komposit dapat berasal dari bahan polimer, logam, maupun
keramik.
Syarat pokok matrik yang digunakan dalam komposit
adalah matrik harus bisa meneruskan beban, sehinga serat
harus bisa melekat pada matrik dan kompatibel antara serat
18
dan
matrik.
Umumnya
matrik
dipilih
yang
mempunyai
ketahanan panas yang tinggi (Triyono & Diharjo, 2000).
Matrik yang digunakan dalam komposit adalah harus
mampu meneruskan beban sehingga serat harus bisa melekat
pada matrik dan kompatibel antara serat dan matrik artinya
tidak ada reaksi yang mengganggu. Menurut Diharjo (1999)
pada bahan komposit matrik mempunyai kegunaan yaitu
sebagai berikut :
 Matrik memegang dan mempertahankan serat pada
posisinya.
 Pada
saat
pembebanan,
merubah
bentuk
dan
mendistribusikan tegangan ke unsur utamanya yaitu serat.
 Memberikan sifat tertentu, misalnya ductility, toughness
dan electrical insulation.
Menurut Diharjo (1999), bahan matrik yang sering
digunakan dalam komposit antara lain :
a. Polimer.
Polimer merupakan bahan matrik yang paling sering
digunakan. Adapun jenis polimer yaitu:

Thermoset, adalah plastik atau resin yang tidak bisa
berubah karena panas (tidak bisa di daur ulang).
Misalnya : epoxy, polyester, phenotic.
19

Termoplastik, adalah plastik atau resin yang dapat
dilunakkan terus menerus dengan pemanasan atau
dikeraskan dengan pendinginan dan bisa berubah
karena panas (bisa didaur ulang).
Misalnya :
Polyamid, nylon, polysurface, polyether.
b. Keramik.
Pembuatan komposit dengan bahan keramik yaitu
Keramik dituangkan pada serat yang telah diatur
orientasinya dan merupakan matrik yang tahan pada
temperatur tinggi. Misalnya :SiC dan SiN yang sampai
tahan pada temperatur 1650 C.
c. Karet.
Karet adalah polimer bersistem cross linked yang
mempunyai kondisi semi kristalin dibawah temperatur
kamar.
d. Matrik logam
Matrik cair dialirkan kesekeliling sistem fiber, yang telah
diatur dengan perekatan difusi atau pemanasan.
e. Matrik karbon.
Fiber yang direkatkan dengan karbon sehingga terjadi
karbonisasi.
Pemilihan matrik harus didasarkan pada kemampuan
elongisasi saat patah yang lebih besar dibandingkan dengan
20
filler. Selain itu juga perlunya diperhatikan berat jenis,
viskositas, kemampuan membasahi filler, tekanan dan suhu
curring, penyusutan dan voids.
Voids (kekosongan) yang terjadi pada matrik sangatlah
berbahaya, karena pada bagian tersebut fiber tidak didukung
oleh matriks, sedangkan fiber selalu akan mentransfer
tegangan ke matriks. Hal seperti ini menjadi penyebab
munculnya crack, sehingga komposit akan gagal lebih awal.
Kekuatan komposit terkait dengan void adalah berbanding
terbalik yaitu semakin banyak void maka komposit semakin
rapuh dan apabila sedikit void komposit semakin kuat.
Dalam pembuatan sebuah komposit, matriks berfungsi
sebagai pengikat bahan penguat, dan juga sebagai pelindung
partikel dari kerusakan oleh faktor lingkungan. Beberapa
bahan matriks dapat memberikan sifat-sifat yang diperlukan
sebagai keliatan dan ketangguhan. Pada penelitian ini matrik
yang digunakan adalah polimer termoset dengan jenis resin
polyester.
Matriks polyester paling banyak digunakan
terutama
untuk aplikasi konstruksi ringan, selain itu harganya murah,
resin ini mempunyai karakteristik yang khas yaitu dapat
diwarnai, transparan, dapat dibuat kaku dan fleksibel, tahan
air, tahan cuaca dan bahan kimia. Polyester dapat digunakan
21
pada suhu kerja mencapai 79 0C atau lebih tergantung partikel
resin dan keperluannya (Schward, 1984). Keuntungan lain
matriks polyester adalah mudah dikombinasikan dengan serat
dan dapat digunakan untuk semua bentuk penguatan plastik.
2.2.3.2.
Perlakuan Alkali ( NaOH )
Sifat alami serat adalah Hyrophilic, yaitu suka terhadap
air berbeda dari polimer yang hidrophilic.Pengaruh perlakuan
alkali terhadap sifat permukaan serat alam selulosa telah
diteliti dimana kandungan optimum air mampu direduksi
sehingga sifat alami hidropholic serat dapat memberikan
ikatan interfecial dengan matrik secra optimal (Bismarck dkk
2002).
NaOH merupakan larutan basa yang tergolong mudah
larut dalam air dan termasuk basa kuat yang dapat terionisasi
dengan sempurna. Menurut teori arrhenius basa adalah zat
yang dalam air menghasilkan ion OH negatif dan ion positif.
Larutan basa memiliki rasa pahit, dan jika mengenai tangan
terasa licin (seperti sabun). Sifat licin terhadap kulit itu disebut
sifat kaustik basa.
Salah satu indikator yang digunakan untuk menunjukkkan
kebasaan
adalah
lakmus
merah.
Bila
lakmus
merah
22
dimasukkan ke dalam larutan basa maka berubah menjadi
biru.
2.2.4. Aspek Geometri
2.2.4.1.
Pengujian Kadar Air
Pengujian ini adalah untuk mengetahui jumlah kadar air yang
terdapat pada serat rami. Uji ini bertujuan untuk menjaga agar
serat rami tetap terjaga kadar airnya yaitu 10%. Pengujian ini
menggunakan alat digital wood moisture contain. Pengujian ini
mempunyai dua fungsi utama yaitu (standar ASTM D 570-98) :
1. Sebagai panduan mengenai proporsi air yang diserap
oleh sebuah bahan.
2. Sebagai tes control mengenai keseragaman sebuah
produk.
2.2.4.2.
Fraksi Volume
Jumlah kandungan serat dalam komposit, merupakan hal
yang menjadi perhatian khusus pada komposit berpenguat serat.
Untuk memperoleh komposit berkekuatan tinggi, distribusi serat
dengan matrik harus merata pada proses pencampuran agar
mengurangi timbulnya void. Untuk menghitung fraksi volume,
parameter yang harus diketahui adalah berat jenis resin, berat
jenis serat, berat komposit dan berat serat. Adapun fraksi volume
yang ditentukan dengan persamaan (Harper, 1996) :
23
................................................. [2.1]
...................................................... [2.2]
Jika selama pembuatan komposit diketahui massa fiber
dan matrik, serta density fiber dan matrik, maka fraksi volume dan
fraksi
massa
fiber
dapat
dihitung
dengan
persamaan
(Shackelford, 1992) :
........................................................... [2.3]
dimana :
Wf
: fraksi berat serat
wf
: berat serat
wc
: berat komposit
ρf
: density serat
ρc
: density komposit
Vf
: fraksi volume serat
Vm
: fraksi volume matrik
vf
: volume serat
vm
: volume matrik
2.2.4.3. Uji density
Pengujian densitas merupakan pengujian sifat fisis terhadap
spesimen, yang bertujuan untuk mengetahui nilai kerapatan massa dari
24
spesimen yang diuji. Rapat massa (mass density) suatu zat adalah
massa zat per satuan volume (Goerge, 2003).
𝜌=
𝑚
𝑣
dimana :
ρ
= densitas benda (gram/cm3)
m
= massa benda (gram)
v
= volume benda (cm3)
Pada benda dengan bentuk yang tidak beraturan, dimana kita
kesulitan untuk menentukan volumenya, kita dapat menghitung
densitas dengan hukum Archimedes. Dalam pengujian densitas disini
pada prinsipnya menentukan massa spesimen diudara (m udara) dan
massa spesimen diair (mair). Massa diudara (mudara) dapat dihitung
dengan timbangan digital secara normal yang merupakan massa
sesungguhnya. Massa dalam air (mair) dapat dihitung dengan cara
massa diudara (mudara) dikurangi gaya keatas, sedangkan gaya ke atas
dapat dihitung dengan teori Archimides. Pada teori Archimides
dikatakan bahwa suatu benda yang dicelupkan dalam suatu fluida akan
mengalami gaya ke atas sama dengan massa fluida yang dipindahkan
oleh benda. Jadi dari teori Archimides tersebut dapat diterapkan untuk
mencari densitas dengan persamaan rumus perhitungan seperti
dibawah ini (Barsoum, 1997) :
𝜌=
(𝑚𝑢𝑑𝑎𝑟𝑎
𝑚𝑢𝑑𝑎𝑟𝑎
− 𝑚𝑓𝑙𝑢𝑖𝑑𝑎 )/𝜌𝑓𝑙𝑢𝑖𝑑𝑎
25
dimana :
mudara = massa spesimen diudara (gram)
mfluida = massa spesimen dalam fluida/air (gram)
ρfluida = densitas fluida/air (gram/cm3)
ρ
= densitas spesimen (gram/cm3)
Gambar 2.7. Skema Uji Densitas (Goerge, 2003).
2.2.4.4. Kekuatan Bending
Material komposit mempunyai sifat tekan lebih baik
dibanding tarik, pada perlakuan uji bending spesimen, bagian atas
spesimen terjadi proses tekan dan bagian bawah terjadi proses
tarik sehingga kegagalan yang terjadi akibat uji bending yaitu
mengalami patah bagian bawah karena tidak mampu menahan
tegangan tarik. Dimensi balok dapat kita lihat pada gambar 2.7.
berikut ini : (Standart ASTM D 790-02 ).
26
P
2
Gambar 2.8. Penampang Uji bending (Standart ASTM D 790-02)
Momen yang terjadi pada komposit dapat dihitung
dengan persamaan :
𝑀 = 𝑃 2 . 𝐿 2…………………………………………………….. [2.4]
Menentukan
kekuatan
bending
menggunakan
persamaan
(Standart ASTM D790-02) :
𝜎=
𝑀. 𝑌
𝐼
𝑃 𝐿 1
. . 𝑑
=2 2 2
1
3
12 . 𝑏 . 𝑑
1
. 𝑃 .𝐿 .𝑑
=8
1
3
12 . 𝑏 . 𝑑
1
𝑃 .𝐿
= 8
1
2
12 𝑏 . 𝑑
𝜎𝑏
=
3𝑃. 𝐿
… … … … … … … … … … … … … … … … … … … . . … … . [2.5]
2 . 𝑏 . 𝑑2
Sedangkan untuk menentukan modulus elastisitas bending
menggunakan rumus sebagai berikut (Standart ASTM D790- 02) :
27
Eb 
L3 .P
………………………....…….............……….[2.6]
4.b.d 3 .
dimana:
b = kekuatan bending (MPa)
P = beban yang diberikan(N)
L = jarak antara titik tumpuan (mm)
b = lebar spesimen (mm)
d = tebal spesimen (mm)
δ = defleksi (mm)
Eb = modulus elastisitas (MPa)
Sedangkan kekakuan dapat dicari dengan persamaan
(Lukkassen, D., Meidel, A., 2003) :
1
𝐼 = 12 𝑏𝑑3 ........................................................................... [2.7]
D = EI ................................................................................. [2.8]
dimana :
D : kekakuan (N/mm2)
E : modulus elastisitas (N/mm2)
I : momen inersia (mm4)
b : lebar (mm)
d : tinggi (mm)
28
2.2.4.5.
Kekuatan Impak
Pengujian impak bertujuan untuk mengukur berapa energi
yang dapat diserap suatu material sampai material tersebut patah.
Pengujian impak merupakan respon terhadap beban kejut atau
beban tiba-tiba (beban impak) (calliester, 2007).
Dalam pengujian impak terdiri dari dua teknik pengujian
standar yaitu Charpy dan Izod. Pada pengujian standar Charpy
dan Izod, dirancang dan masih digunakan untuk mengukur energi
impak yang juga dikenal dengan ketangguhan takik (Calliester,
2007).
Spesimen Charpy berbentuk batang dengan penampang
lintang bujur sangkar dengan takikan V oleh proses permesinan
(gambar 2.2.a). Mesin pengujian impak diperlihatkan secara
skematik
dengan
(gambar
2.2.b).
Beban
didapatkan
dari
tumbukan oleh palu pendulum yang dilepas dari posisi ketinggian
h. Spesimen diposisikan pada dasar seperti pada (gambar 2.2.b)
tersebut. Ketika dilepas, ujung pisau pada palu pendulum akan
menabrak dan mematahkan spesimen ditakikannya yang bekerja
sebagai
titik
konsentrasi
tegangan
untuk
pukulan
impak
kecepatan tinggi. Palu pendulum akan melanjutkan ayunan untuk
mencapai ketinggian maksimum h’ yang lebih rendah dari h.
Energi yang diserap dihitung dari perbedaan h’ dan h (mgh –
mgh’), adalah ukuran dari energi impak. Posisi simpangan lengan
29
pendulum terhadap garis vertikal sebelum dibenturkan adalah α
dan posisi lengan pendulum terhadap garis vertikal setelah
membentur spesimen adalah β. Dengan mengetahui besarnya
energi potensial yang diserap oleh material maka kekuatan impak
benda uji dapat dihitung (Standar ASTM D256-00).
Eserap = energi awal – energi yang tersisa
= m.g.h – m.g.h’
= m.g.(R-Rcos α) – m.g.(R- R.cos β)
= mg.R.(cos β - cos α) ..........................................[2.9]
Esrp
dimana :
Esrp : energi serap (J)
m
: berat pendulum (kg) = 20 kg
g
: percepatan gravitasi (m/s2) = 10 m/s2
R
: panjang lengan (m) = 0,8 m
α
: sudut pendulum sebelum diayunkan = 30o
β
:
sudut
ayunan
pendulum
setelah
mematahkan
specimen
Harga impak dapat dihitung dengan :
𝐻𝐼 =
𝐸𝑠𝑟𝑝
𝐴𝑜
................................................................................. [2.10]
dimana :
HI
: Harga Impak (J/mm2)
Esrp : energi serap (J)
Ao
: Luas penampang (mm2)
30
Gambar 2.9. (a) Spesimen yang digunakan untuk pengujian
impak. (b) Skematik peralatan uji impak. (Callister, 2007).
Pengujian impak dapat diidentifikasi sebagai berikut :
1. Material yang getas, bentuk patahannya akan bermukaan
merata, hal ini menunjukkan bahwa material yang getas akan
cenderung patah akibat tegangan normal.
2. Material yang ulet akan terlihat meruncing, hal ini menunjukkan
bahwa material yang ulet akan patah akibat tegangan geser.
3. Semakin besar posisi sudut β akan semakin getas, demikian
sebaliknya.
Artinya
pada
material
getas,
energy
untuk
31
mematahkan material cenderung semakin kecil, demikian
sebaliknya.
2.2.4.6.
Pengujian Kekuatan Tarik
Pengujian tarik bertujuan untuk mengetahui tegangan,
regangan, modulus elastisitas bahan dengan cara menarik
spesimen sampai putus. Pengujian tarik dilakukan dengan mesin
uji tarik atau dengan universal testing standar.(Standar ASTM D
638-02).
Hal-hal yang mempengaruhi kekuatan tarik komposit
antara lain :(Surdia, 1995).
a. Temperatur
Apabila temperatur naik, maka kekuatan tariknya akan turun
b. Kelembaban
Pengaruh
kelembaban
ini
akan
mengakibatkan
bertambahnya absorbsi air, akibatnya akan menaikkan
regangan patah, sedangkan tegangan patah dan modulus
elastisitasnya menurun.
c.
Laju Tegangan
d.
Apabila
laju
tegangan
kecil,
maka
perpanjangan
bertambah dan mengakibatkan kurva tegangan-regangan
menjadi landai, modulus elastisitasnya rendah. Sedangkan
kalau laju tegangan tinggi, maka beban patah dan modulus
elastisitasnya meningkat tetapi regangannya mengecil.
32
Hubungan antara tegangan dan regangan pada beban tarik
ditentukan dengan rumus sebagai berikut (Surdia, 1995)
P = σ . A atau σ =
P
..................................................... [2.11]
A
Catatan:
P = beban (N)
A = luas penampang (mm2)
σ = tegangan (MPa).
Besarnya regangan adalah jumlah pertambahan panjang
karena pembebanan dibandingkan dengan panjang daerah
ukur (gage length). Nilai regangan ini adalah regangan
proporsional yang didapat dari garis. Proporsional pada
grafik tegangan-tegangan hasil uji tarik komposit.(Surdia,
1995)

=
L
......................................................................... [2.12]
lo
Dimana:

= Regangan (mm/mm)
ΔL = pertambahan panjang (mm)
lo = panjang daerah ukur (gage length), mm
Pada daerah proporsional yaitu daerah dimana teganganregangan yang terjadi masih sebanding, defleksi yang terjadi
masih bersifat elastis dan masih berlaku hukum Hooke.
Besarnya nilai modulus elastisitas komposit yang juga
33
merupakan perbandingan antara tegangan dan regangan
pada daerah proporsional dapat dihitung dengan persamaan
(Surdia, 1995)

E =  ........................................................................... [2.13]
Dimana:
E = Modulus elastisitas tarik (MPa)
 = Kekuatan tarik (MPa)

= Regangan (mm/mm)
2.2.5. Perpatahan (Fracture)
2.2.5.1
Dasar-dasar Perpatahan.
Kegagalan dari bahan teknik hampir selalu tidak
diinginkan
terjadi
karena
beberapa
alasan
seperti
membahayakan hidup manusia, kerugian dibidang ekonomi dan
gangguan terhadap ketersediaan produk dan jasa. Meskipun
penyebab kegagalan dan sifat bahan mungkin diketahui,
pencegahan terhadap kegagalan sulit untuk dijamin. Kasus
yang sering terjadi adalah pemilihan bahan dan proses yang
tidak tepat dan perancangan komponen kurang baik serta
penggunaan yang salah. Menjadi tanggung jawab para insinyur
untuk mengantisipasi kemungkinan kegagalan dan mencari
penyebab
pada
kegagalan
kegagalan lagi(Calliester, 2007).
untuk
mencegah
terjadinya
34
Patah sederhana didefinisikan sebagai pemisahan
sebuah bahan menjadi dua atau lebih potongan sebagai respon
dari tegangan static yang bekerja dan pada temperatur yang
relative rendah terhadap temperatur cairnya. Dua model patah
yang mungkin terjadi pada bahan teknik adalah patah liat
(ductile fracture) dan patah getas (brittle fracture). Klasifikasi ini
didasarkan pada kemampuan bahan mengalami deformasi
plastik. Bahan liat (ductile) memperlihatkan deformasi plastik
dengan
menyerap
energi
yang
besar
sebelum
patah.
Sebaliknya, patah getas hanya memeperlihatkan deformasi
plastik yang kecil atau bahkan tidak ada. Setiap proses
perpatahan
perambatan
diterapkan.
meliputi dua
sebagai
Jenis
tahap
respon
perpatahan
yaitu
pembentukan
dan
terhadap
tegangan
yang
tergantung
pada
sangat
mekanisme perambatan retak (Callister, 2007).
35
BAB III
PELAKSANAAN PENELITIAN
3.1. Penyiapan Bahan dan Alat
3.1.1. Penyiapan bahan
Bahan yang digunakan dalam penelitian ini adalah sebagai berikut:
a. Serat rami
Serat rami dicuci dahulu untuk menghilangkn kotoran yang
ada pada serat, kemudian serat dijemur. Setelah melalui proses
penjemuran serat dioven sampai kadar air menjadi 10%.
Gbr 3.1. Serat rami sebelum diacak
Gbr 3.2. serat rami setelah diacak
35
36
b. Poliester
Matrik yang digunakan Resin Polyester BQTN tipe 157
dengan bahan tambahan katalis yang berfungsi sebagai pengeras
resin.
Gambar 3.3. Resin Polyester Yucalac tipe 157 dan katalis
c. NaOH
NaOH digunakan untuk menghilangkan kotoran atau lignin
pada serat dengan kadar 5 %. NaOH merupakan larutan basa
dan terkesan licin.
Gambar 3.4. Larutan NaOH
37
3.1.2. Penyiapan Alat.
a. Timbangan digital
Timbangan yang digunakan untuk menimbang serat dan
polyester adalah timbangan digital.
Gambar 3.5. Timbangan Digital.
b. Alat Uji Kadar Air.
Alat uji kadar air ini digunakan untuk mengukur kadar air
serat rami, dengan ketentuan kadar air 10%.
Gambar 3.6. wood moisture meter.
38
c. Cetakan Benda Uji
Cetakan yang digunakan terbuat dari kaca bening dengan
ketebalan 3mm, 4mm, dan 5 mm.
Gambar 3.7. Cetakan untuk benda uji.
d.
Alat Pengepres Cetakan.
Untuk penekan digunakan alat pres mold
Gambar 3.8. Alat Pengepres Cetakan.
e. Alat Bantu lain
39
Alat Bantu lain yang digunakan, meliputi : sendok, cutter,
gunting, kuas, pisau, spidol, kit mobil, penggaris, dan gelas ukur.
Gambar 3.9. Alat bantu lain.
f. Grenda pemotong dan amplas
Grenda pemotong digunakan untuk memotong komposit
menjadi spesimen dan untuk menghaluskan permukaan bekas
potongan digunakan amplas.
40
3.2. Diagram Alir
Mulai
Study Literatur dan
Survey Lapangan
Persiapan
Bahan
Perlakuan Alkali
Serat Rami
Dengan Vf 20%,
30%, 40%, 50%
Pembuatan cetakan dengan
variasi ketebalan 1mm, 2mm,
3mm, 4mm, dan 5mm,
Resin polyeter
dan MEKPO 1%
Pembuatan Komposit Skin dengan serat acak
(Mat Fiber Composit) dengan metode pres
mold
Pembuatan Spesimen
sesuai Standart
Pengujian :
Uji bending
(ASTM D790-02)
Uji impak
(ASTM D256-00)
Uji tarik
(ASTM D638-02)
Hasil
Analisa dan Pembahasan
Kesimpulan
Selesai
Gambar 3.10. Diagram alir penelitian
Foto Makro
41
3.2.1. Survey Lapangan dan Study Literature.
Proses yang dilakukan pada penelitian ini adalah dengan
mengumpulkan data awal sebagai study literature. Study literature
bertujuan untuk mengenal masalah yang dihadapi, serta untuk
menyusun rencana kerja yang akan dilakukan. Pada studi awal
dilakukan langkah-langkah seperti survey dilapangan terhadap hal-hal
yang berhubungan dengan penelitian yang akan dilakukan serta
mengambil data-data penelitian yang sudah ada untuk dijadikan
sebagai pembanding terhadap hasil pengujian yang akan dianalisa.
Selain itu pada proses ini juga dilakukan perancangan alat pres-mold
yang digunakan untuk membuat spesimen yang sesuai dengan karakter
matrik yang dipakai.
3.2.2. Penyiapan bahan
Mengumpulkan semua bahan-bahan yang akan digunakan
dalam proses pembuatan komposit skin. Diantaranya yaitu serat rami,
larutan NaOH dan polyester beserta katalis.
3.2.3. Pembuatan Komposit
Proses pembuatan komposit serat rami dengan matrik polyester
adalah sebagai berikut:
42
1. Penyiapan serat rami, untuk serat rami dicuci dahulu, kemudian
dimasukkan kedalam larutan NaOH 5% selama 2jam, 4jam, 6jam
dan 8jam, lalu dikeringkan sampai kadar air mecapai 10%.
2. Setelah serat kering kemudian dilakukan proses pembuatan serat
secara acak sesuai bentuk cetakan.
3. Pembuatan cetakan
Untuk pengujian bending dan impak menggunakan kaca dengan
ketebalan 3mm, 4mm, dan 5mm.
Tebal
Ukuran cetakan
Daerah pencetakan
3mm
230 x 205 x 16mm
150 x 125 x 3mm
4mm
230 x 205 x 17mm
150 x 125 x 4mm
5mm
230 x 205 x 18mm
150 x 125 x 5mm
komposit
Untuk tebal komposit 1mm menggunakan tebal cetakan 5mm
ditambahkan kaca 4mm kedalam cetakan untuk mengurangi volume
cetakan dan penambahan kaca 3mm kedalam cetakan untuk tebal
komposit 2mm.
4. Pengolesan wax mold release atau kit motor pada cetakan untuk
memudahkan
pengambilan
benda
uji
dari
cetakan
setelah
mengalami proses pengeringan.
5. Resin polyester dicampur dengan katalis untuk membantu proses
pengeringan. Katalis yang digunakan sebanyak 1% dari banyaknya
resin poliester yang digunakan.
43
6. Penuangan campuran resin sebagian dari takaran kedalam cetakan,
dilanjutkan penempatan serat rami yang telah disusun secara acak,
kemudian diatas serat dituang kembali sisa campuran resin pada
gelas takaran kedalam cetakan sambil dipukul-pukul dengan sendok
biar campuran resin masuk kedalam serat yang kemudian ditutup
dengan kaca dan ditekan dengan dengan alat penekan.
7. Penutupan dengan menggunakan kaca yang bertujuan agar void
yang kelihatan dapat diminimalkan jumlahnya yang kemudian
dilakukan pengepresan dengan menggunakan alat pengepres.
8. Proses pengeringan dilakukan sampai benar-benar kering yaitu 5 –
10 jam dan apabila masih belum benar-benar kering maka proses
pengeringan dapat dilakukan lebih lama
9. Proses pengambilan komposit dari cetakan yaitu menggunakan
pisau ataupun cutter.
10. Benda uji komposit siap untuk dipotong menjadi spesimen benda uji.
Berikut beberapa gambar dari Komposit serat Rami dengan
menggunakan matrik resin polyester.
44
Gambar 3.11. Hasil cetakan komposit serat Rami dengan
matrik polyester
Gambar 3.12. Spesimen uji tarik komposit serat rami
Gambar 3.13. Spesimen uji bending komposit serat rami
45
Gambar 3.14. Spesimen uji impak komposit serat rami.
3.2.4. Pengujian Komposit
Pengujian yang dilakukan pada penelitian ini antara lain
pengujian bending, pengujian impak,dan foto makro.
3.2.4.1. Pengujian bending.
Material komposit mempunyai sifat tekan yang lebih baik
dibanding sifat tariknya. Kekuatan tarik di pengaruhi oleh ikatan
molekul material penyusunnya. Pada pengujian bending ini
bertujuan untuk mengetahui besarnya kekuatan lentur dari
material komposit. Pengujian dilakukan dengan jalan memberi
beban lentur secara perlahan-lahan sampai spesimen mencapai
titik lelah. Pada perlakuan uji bending bagian atas spesimen
mengalami proses penekanan dan bagian bawah mengalami
proses tarik sehingga akibatnya spesimen mengalami patah
bagian bawah karena tidak mampu menahan tegangan tarik.
Spesimen uji bending dibuat sesuai standar ASTM D790 – 02.
46
Langkah-langkah pengujian bending yaitu :
1. Mempersiapkan benda uji.
2. Menentukan titik tumpuan dan titik tengah benda uji dengan
memberi tanda garis.
3. Menentukan besarnya beban yang digunakan.
4. Meletakkan spesimen pada meja mesin pengujian bending
dengan jarak tumpuan dan titik tengah yang telah ditentukan.
5. Putar handle sampai beban menyentuh benda uji dan
manometer indikator menunjukkan angka nol.
6. Tentukan putaran jarum penentu waktu untuk pencatatan
beban selanjutnya.
7. Catat hasil pengujian bending setiap putaran yang telah
ditentukan.
8. Menentukan harga bending.
Gambar 3.15. Dimensi pengujian bending Standar ASTM D 790-02
47
Gambar 3.16. Mesin Pengujian Bending
(Laboratorium Material Teknik UMS)
3.2.4.2. Pengujian impak
Pada uji impak charpy kita mengukur energi yang diserap
untuk mematahkan benda uji. Setelah benda uji patah, bandul
berayun kembali. Makin besar energi yang diserap makin rendah
ayunan kembali dari bandul. Energi patahan yang diserap
biasanya dinyatakan dalam satuan joule.
Prinsip dari pengujian impak ini adalah apabila benda uji
diberi beban kejut, maka benda akan mengalami proses
penyerapan energi sehingga terjadi deformasi plastis yang
mengakibatkan patah.
48
Untuk mengetahui ketahanan benda terhadap keadaan
patah, maka digunakan metode pengujian impak charphy.
Langkah-langkah pengujian impak :
1. Mengukur dimensi dari skin yaitu tebal, lebar, dan
panjangnya,
kemudian memberikan no spesimen pada
skin yang akan diuji.
2. Mengangkat beban palu.
3. Meletakkan spesimen pada batang uji atau tumpuan dengan
bantuan penjepit.
4. Melepaskan palu atau bandul dengan cara menekan tombol
dan menarik handel-nya.
5. Palu akan jatuh dan memukul spesimen secara otomatis.
6. Catat energi serap yang ditunjukkan oleh jarum pada alat uji
impak.
7. Hitung harga impak.
Keretakan akibat uji impak ada tiga bentuk yaitu :
1. Patahan getas
Permukaan patahan terlihat rata dan mengkilap, kalau
potongan-potongannya
kita
sambungkan
lagi,
ternyata
keretakannya tidak disertai dengan deformasinya bahan.
Patahan jenis ini mempunyai harga impak yang rendah.
49
2. Patahan liat.
Permukaan patahan ini tidak rata, nampak seperti buram dan
berserat, tipe ini mempunyai harga impak yang tinggi.
3. Patahan campuran.
Patahan yang terjadi merupakan campuran dari patahan
getas dan patahan liat. Patahan ini paling banyak terjadi.
Gambar 3.17. Mesin pengujian impak charpy
( Laboratorium Material Teknik Mesin UMS )
Gambar 3.18. Dimensi impak ASTM D 5942-96
50
Prinsip dari pengujian impak ini adalah apabila benda uji
diberi beban kejut, maka benda akan mengalami proses
penyerapan energi sehingga terjadi deformasi plastis yang
mengakibatkan perpatahan.
3.2.4.2. Pengujian Tarik
Pengujian tarik dilakukan untuk mengetahui besarnya
kekuatan tarik dari bahan komposit. Pengujian dilakukan dengan
mesin uji “Universal Testing Machine” buatan jepang. Spesimen
pengujian tarik di bentuk menurut standar ASTM D 638-03 tipe 4
yang ditunjukkan pada gambar berikut:
Lo=33mm
B=6mm
R=14mm
Z=115mm
G
Gambar 3.19. Dimensi benda pengujian tarik
Dimana:
Lo : panjang paralel (mm)
b : Lebar (mm)
Z : Panjang total spesimen (mm)
51
d : Tebal (mm)
A : Lebar pegangan (mm)
Langkah-langkah pengujian tarik dalam penelitian ini adalah
sebagai berikut:
1. Ukur panjang uji dan penempang uji sebelum diuji.
2. Siapkan mesin uji tarik yang digunakan.
3. Masukkan dan seting kertas milimeter-blok diatas mesin plotter.
4. Pasang spesimen tarik dan pastikan terjepit dengan betul.
5. Jalankan mesin uji tarik.
6. Setelah patah, hentikan proses penarikan secepatnya, catat gaya
tarik maksimum dan pertambahan panjangnya.
7. Ambil hasil rekaman mesin plotter dari proses penarikan yang
tertuang dalam kertas milimeter-blok.
Gambar 3.20. Mesin pengujian tarik
( Laboratorium Material Teknik Mesin UMS )
52
3.2.4.3. Foto Patahan Makro
Pengambilan foto makro bertujuan untuk mengetahui
jenis/bentuk patahan dan pola kegagalan yang terjadi pada
spesimen komposit akibat pengujian bending dan impak. Objek
yang diambil dari penampang patahan dan dari samping untuk
pengujian impak sedangkan untuk bending diambil dari samping
benda uji.
Adapun langkah-langkah pengambilan foto patahan makro
adalah sebagai berikut:
1. Nyalakan lampu sebagai sumber cahaya.
2. Letakkan spesimen pada “Stage Plate”.atau meja objek.
3. Memasang lensa repro pada kamera dan atur perbesaran
yang diinginkan.
4. Lihat gambar pada “LCD” yaitu pada layar kamera.
5. Fokuskan gambar.
6. Untuk melakukan pemotretan:
a. Dilakukan dengan kamera digital Nikon E3500, 7.1 Mega
pixel.
b. Tekan “Expose” untuk melakukan pemotretan
7. Melihat hasil pemotretan.
53
BAB IV
HASIL PENELITIAN DAN PEMBAHASAN
4.1. Pengujian Bending
4.1.1. Data Hasil Pengujian Bending Alkali 2 Jam.
Table 4.1.1.1. Data hasil pengujian bending rata-rata pada tebal 1mm
Jenis
Komposit
Fraksi
volume
20%
Fraksi
volume
30%
Fraksi
volume
40%
Fraksi
volume
50%
Momen
Bending
Rata-rata
Tegangan
Bending
Rata-rata
Defleksi
Bending
Rata-rata
(Nmm)
(MPa)
(mm)
Modulus
Elastisitas
Bending
Rata-rata
(MPa)
213,424
55,97055
2,376
1884,05211
4839,83537
228,642
38,70191
3,545
700,82351
3499,27007
205,570
18,24936
4,505
199,97964
2559,10614
599,567
74,30054
1,396
2995,64239
23148,5484
Kekakuan
Bending
Rata-rata
(Nmm2)
Table 4.1.1.2. Data hasil pengujian bending rata-rata pada tebal 2mm
Jenis
Komposit
Fraksi
volume
20%
Fraksi
volume
30%
Fraksi
volume
40%
Fraksi
volume
50%
Momen
Bending
Rata-rata
Tegangan
Bending
Rata-rata
Defleksi
Bending
Rata-rata
(Nmm)
(MPa)
(mm)
Modulus
Elastisitas
Bending
Rata-rata
(MPa)
946,775
100,9908
1,852
4069,78937
593,575
34,4637
1,894
989,51153
537,350
33,8882
1,028
1833,96408
39530,369
1838,825
74,4255
1,943
1859,34807
,76933,570
53
Kekakuan
Bending
Rata-rata
(Nmm2)
40217,455
23763,342
54
Tabel 4.1.1.3. Data hasil pengujian bending rata-rata pada tebal 3mm
Jenis
Komposit
Fraksi
volume
20%
Fraksi
volume
30%
Fraksi
volume
40%
Fraksi
volume
50%
Momen
Bending
Rata-rata
Tegangan
Bending
Rata-rata
Defleksi
Bending
Rata-rata
(Nmm)
(MPa)
(mm)
Modulus
Elastisitas
Bending
Rata-rata
(MPa)
1198,458
51,4811
2,643
2848,62956
101211,,969
1567,083
39,6608
2,213
1806,63456
151084,496
4241,833
143,9594
2,259
7253,41067
391090,483
1760,166
41,6608
2,831
1300,21282
123368,528
Kekakuan
Bending
Rata-rata
(Nmm2)
Jenis
Komposit
Fraksi
volume
20%
Fraksi
volume
30%
Fraksi
volume
40%
Fraksi
volume
50%
Momen
Bending
Rata-rata
Tegangan
Bending
Rata-rata
Defleksi
Bending
Rata-rata
(Nmm)
(MPa)
(mm)
Modulus
Elastisitas
Bending
Rata-rata
(MPa)
2792,725
67,7365
7,021
1586,66787
139886,556
2983,121
63,8266
6,818
1427,32660
155910,587
1963,054
29,0413
18,968
208,36962
38846,421
6205,170
111,8048
4,830
3091,58165
441537,555
Kekakuan
Bending
Rata-rata
(Nmm2)
55
Jenis
Komposit
Fraksi
volume
20%
Fraksi
volume
30%
Fraksi
volume
40%
Fraksi
volume
50%
Momen
Bending
Rata-rata
Tegangan
Bending
Rata-rata
Defleksi
Bending
Rata-rata
(Nmm)
(MPa)
(mm)
Modulus
Elastisitas
Bending Ratarata
(MPa)
4142,133
58,8363
8,797
1327,05801
253517,2649
3790,933
63,5019
12,364
1045,49661
164533,6752
4904,540
67,4877
4,541
2797,49988
586992,0176
6257,060
60,3870
4,433
2175,88513
789882,4878
Kekakuan
Bending
Rata-rata
(Nmm2)
7000
6257,06
6205,17
Momen bending rata-rata
(mm4)
6000
5000
4000
3000
2000
1838,83
1760,17
1000
599,567
0
0%
10%
20%
30%
40%
50%
60%
Fraksi volume
(%)
Tebal 1mm
Tebal 2mm
Tebal 3mm
Tebal 4mm
Tebal 5mm
Gambar 4.1. Grafik hubungan momen bending rata-rata dengan fraksi
volume terhadap tebal komposit.
56
Tegangan bending rata-rata
(MPa)
160
140
120
111,8048
100
80
60
74,42552
74,30054
60,38704
40
41,66083
20
0
0%
10%
20%
30%
40%
50%
60%
Fraksi volume
(%)
Tebal 1mm
Tebal 2mm
Tebal 3mm
Tebal 4mm
Tebal 5mm
Gambar 4.2. Grafik hubungan tegangan bending rata-rata dengan
Defleksi bending rata-rata
(mm)
fraksi volume terhadap tebal komposit.
20
18
16
14
12
10
8
6
4
2
0
4,83
4,433
2,831
1,943
1,396
0%
10%
20%
30%
40%
50%
60%
Fraksi volume
(%)
Tebal 1mm
Tebal 2mm
Tebal 3mm
Tebal 4mm
Tebal 5mm
Gambar 4.3. Grafik hubungan defleksi bending rata-rata dengan
Modulus elastisitas bending rata-rata
(MPa)
57
8000
7000
6000
5000
4000
3000
3091,582
2995,642
2000
2175,885
1859,348
1300,213
1000
0
0%
10%
20%
30%
40%
50%
60%
Fraksi volume
(%)
Tebal 1mm
Tebal 2mm
Tebal 3mm
Tebal 4mm
Tebal 5mm
Gambar 4.4. Grafik hubungan modulus elastisitas bending rata-rata
dengan fraksi volume terhadap tebal komposit.
Kekakuan bending rata-rata
(N/mm2)
900000
800000
789882,4878
700000
600000
500000
441537,555
400000
300000
200000
123368,5286
76933,57076
23148,5484
100000
0
0%
10%
20%
30%
40%
50%
60%
Fraksi volume
(%)
Tebal 1mm
Tebal 2mm
Tebal 3mm
Tebal 4mm
Tebal 5mm
Gambar 4.5. Grafik hubungan kekakuan bending rata-rata dengan
58
4.1.1.
Pembahasan Pengujian Bending Dengan Perlakuan
Alkali 2 jam.
Dari data-data yang telah diperoleh dapat disimpulkan
bahwa harga kekuatan bending komposit serat acak rami pada
spesimen tebal 1mm Vf 50% (74,30054 MPa), lebih besar dari
Vf 20%, Vf 30%, Vf 40% yaitu 55,97055 MPa, 38,70191 MPa,
18,24936 MPa. Pada spesimen tebal 2mm Vf 20% (100,9908
MPa), lebih besar dari Vf 30%, Vf 40%, Vf 50% yaitu 34,4637
MPa, 33,8882 MPa, 74,4255 MPa. Pada spesimen tebal 3mm
Vf 40% (143,9594 MPa), lebih besar dari Vf 20%, Vf 30%, Vf
50% yaitu 51,4811 MPa, 39,6608 MPa, 41,6608 MPa. Pada
MPa, 63,5019 MPa, 60,3870 MPa. Dari data-data yang telah
diperoleh menunjukkan harga kekuatan bending optimal yaitu
pada spesimen tebal 3mm Vf 40% sebesar 143,9594 MPa, ini
dikarenakan momen material komposit pada variasi ini memiliki
harga yang tertinggi.
Sedangkan
modulus
elastisitas
rata-rata
tertinggi
komposit serat rami acak pada spesimen tebal 1mm Vf 50%
(2995,64239 MPa), lebih besar dari Vf 20%, Vf 30%, Vf 40%
59
yaitu 1884,05211 MPa, 700,823517 MPa, 199,97964 MPa.
Pada spesimen tebal 2mm Vf 20% (4069,78937 MPa), lebih
besar dari Vf 30%, Vf 40%, Vf 50%
yaitu 989,51153 MPa,
1833,96408 MPa, 1859,34807 MPa. Pada spesimen tebal 3mm
50%
yaitu 2848,62956 MPa, 1806,63456 MPa, 1300,21282
MPa. Pada spesimen tebal 4mm Vf 50% (3091,58165 MPa),
lebih besar dari Vf 20%, Vf 30%, Vf 40% yaitu 1586,66787 MPa,
50%
yaitu 1327,05801 MPa, 1045,49661 MPa, 2175,88513
MPa. Dari data-data yang telah diperoleh harga modulus
elastisitas bending optimal yaitu pada spesimen tebal 3mm Vf
40% sebesar 7253,41067 MPa.
60
Table 4.6. Data hasil pengujian bending rata-rata pada tebal 1mm
Momen
Bending
Rata-rata
Tegangan
Bending
Rata-rata
Defleksi
Bending
Rata-rata
(Nmm)
(MPa)
(mm)
Modulus
Elastisitas
Bending
Rata-rata
(MPa)
62,8666
2,256
2252,5189
5770,58849
33,2409
2,233
960,0569
4663,31747
391,138
34,5953
2,732
624,5529
8100,30505
452,966
55,8130
4,093
887,0887
6897,15191
Jenis
Komposit
Fraksi
volume
20%
Fraksi
volume
30%
Fraksi
volume
40%
Fraksi
volume
50%
239,564
193,442
Kekakuan
Bending
Rata-rata
(Nmm2)
Momen
Bending
Rata-rata
Tegangan
Bending
Rata-rata
Defleksi
Bending
Rata-rata
(Nmm)
(MPa)
(mm)
Modulus
Elastisitas
Bending
Rata-rata
(MPa)
Fraksi
volume 20%
574,975
61,0075
2,848
1576,3669
15656,5791
Fraksi
volume 30%
641,9
2,671
797,9732
19438,07467
Fraksi
volume 40%
1877,15
1,696
3814,1518
82203,3813
Fraksi
volume 50%
2455,6
2,052
2160,0695
89834,90114
Jenis
Komposit
37,2716
119,5723
99,3298
Kekakuan
Bending
Rata-rata
(Nmm2)
61
Tabel 4.8. Data hasil pengujian bending rata-rata pada tebal 3mm
Jenis
Komposit
Fraksi
volume
20%
Fraksi
volume
30%
Fraksi
volume
40%
Fraksi
volume
50%
Momen
Bending
Rata-rata
Tegangan
Bending
Rata-rata
Defleksi
Bending
Rata-rata
(Nmm)
(MPa)
(mm)
Modulus
Elastisitas
Bending
Rata-rata
(MPa)
1364,750
57,9439
2,591
3611,6808
130378,4937
1293,208
34,0783
1,270
2593,4177
215638,1473
1372,25
46,0235
2,213
2402,9037
130896,9267
2862,916
67,0127
1,371
4896,9335
470495,5037
Kekakuan
Bending
Rata-rata
(Nmm2)
(MPa)
Defleksi
Bending
Ratarata
(mm)
Modulus
Elastisitas
Bending
Rata-rata
(MPa)
2532,467
36,0286
6,367
1153,0738
216760,7534
Fraksi
volume
30%
4201,533
70,1437
7,012
2111,1889
338571,7448
Fraksi
volume
40%
6625,733
64,2087
2,911
3707,22952
1320731,722
Fraksi
volume
50%
7748,733
106,4359
4,192
4687,609145
992668,6561
Momen
Bending
Rata-rata
Tegangan
Bending
Rata-rata
(Nmm)
Fraksi
volume
20%
Jenis
Komposit
Kekakuan
Bending
Rata-rata
(Nmm2)
62
Momen
Bending
Rata-rata
Tegangan
Bending
Rata-rata
Defleksi
Bending
Rata-rata
(Nmm)
(MPa)
(mm)
Modulus
Elastisitas
Bending
Rata-rata
(MPa)
Fraksi
volume 20%
1997,775
48,0787
3,522
2373,4008
209108,7464
Fraksi
volume 30%
3800,1166
67,616031
4,168
2255,9084
324737,0704
Fraksi
volume 40%
4560,075
67,5851
3,282
2802,1701
513118,2639
Fraksi
volume 50%
4121
88,12637
2,719
5053,48233
550364,9035
Jenis
Komposit
Kekakuan
Bending
Rata-rata
(Nmm2)
9000
(mm4)
8000
7748,73
7000
6000
5000
4000
4121
3000
2862,917
2455,6
2000
1000
452,966
0
0%
10%
20%
30%
40%
50%
60%
Fraksi volume
(%)
Tebal 1mm
Tebal 2mm
Tebal 3mm
Tebal 4mm
Tebal 5mm
Gambar 4.6. Grafik hubungan momen bending rata-rata
dengan fraksi volume terhadap tebal komposi
63
(MPa)
140
120
106,4359297
99,329893
88,1263793
100
80
67,01279282
55,813064
60
40
20
0
0%
10%
20%
30%
40%
50%
60%
Fraksi volume
(%)
Tebal 1mm
Tebal 2mm
Tebal 3mm
Tebal 4mm
Tebal 5mm
Gambar 4.7. Grafik hubungan tegangan bending rata-rata dengan
fraksi volume terhadap tebal komposit
(mm)
8
7
6
5
4,192
4,093
4
3
2,719
2,052
1,371
2
1
0
0%
10%
20%
30%
40%
50%
60%
Fraksi volume
(%)
Tebal 1mm
Tebal 2mm
Tebal 3mm
Tebal 4mm
Tebal 5mm
(MPa)
64
6000
5053,48233
4896,933587
4687,609145
5000
4000
3000
2000
2160,0695
1000
887,088
0
0%
10%
20%
30%
40%
50%
60%
Fraksi volume
(%)
Tebal 1mm
Tebal 2mm
Tebal 3mm
Tebal 4mm
Tebal 5mm
Gambar 4.9. Grafik hubungan modulus elastisitas bending rata-rata
(N/mm2)
1400000
1200000
1000000
992668,6561
800000
600000
550364,9035
470495,5037
400000
200000
89834,90114
6897,15191
0
0%
10%
20%
30%
40%
50%
60%
Fraksi volume
(%)
Tebal 1mm
Tebal 2mm
Tebal 3mm
Tebal 4mm
Tebal 5mm
65
4.1.2.1
Pembahasan Pengujian Bending Dengan
Perlakuan Alkali 4 Jam
spesimen tebal 1mm Vf 20% (62,8666 MPa), lebih besar dari Vf
30%, Vf 40%, Vf 50% yaitu 33,2409 MPa, 34,5953 MPa,
MPa, 37,2716 MPa, 99,3298 MPa. Pada spesimen tebal 3mm
Vf 50% (67,0127 MPa), lebih besar dari Vf 20%, Vf 30%, Vf 40%
yaitu 57,9439 MPa, 34,0783 MPa, 46,0235 MPa. Pada
20%, Vf 30%, Vf 40%
67,585148
MPa.
Pada
yaitu 48,0787 MPa, 67,616031MPa,
spesimen
tebal
5mm
Vf
50%
yaitu 36,0286 MPa, 70,1437 MPa, 64,20870 MPa. Dari datadata yang telah diperoleh menunjukkan harga kekuatan bending
optimal yaitu pada spesimen tebal 2mm Vf 40% sebesar
119,5723 MPa, ini dikarenakan momen material komposit pada
variasi ini memiliki harga yang tertinggi.
Sedangkan
modulus
elastisitas
rata-rata
tertinggi
(2252,5189 MPa), lebih besar dari Vf 30%, Vf 40%, Vf 50% yaitu
66
960,0569 MPa, 624,5529 MPa, 887,0887 MPa. Pada spesimen
tebal 2mm Vf 40% (3814,1518 MPa), lebih besar dari Vf 20%, Vf
30%, Vf 50% yaitu 1576,3669 MPa, 797,9732 MPa, 2160,0695
MPa. Pada spesimen tebal 3mm Vf 50% (4896,9335 MPa), lebih
40% yaitu 2373,4008 MPa, 2255,90842 MPa, 2802,1701 MPa.
Pada spesimen tebal 5mm Vf 50% (4687,60914 MPa), lebih
2111,1889 MPa, 3707,22952 MPa. Dari data-data yang telah
diperoleh harga modulus elastisitas bending optimal yaitu pada
spesimen tebal 4mm Vf 50% sebesar 5053,48233 MPa.
67
Jenis
Komposit
Fraksi
volume
20%
Fraksi
volume
30%
Fraksi
volume
40%
Fraksi
volume
50%
Momen
Bending
Rata-rata
Tegangan
Bending
Rata-rata
Defleksi
Bending
Rata-rata
(Nmm)
(MPa)
(mm)
Modulus
Elastisitas
Bending
Rata-rata
(MPa)
Kekakuan
Bending
Rata-rata
(Nmm2)
132,652
35,0543
3,706
782,0684
2018,934159
180,1918
30,3453
5,029
396,2280
1942,629864
517,8001
45,8119
647,4459
8351,128725
417,9993
52,1525
1193,8059
9225,10121
3,350
2,426
Momen
Bending
Rata-rata
Tegangan
Bending
Rata-rata
Defleksi
Bending
Ratarata
Modulus
Elastisitas
Bending
Rata-rata
Kekakuan
Bending
Rata-rata
(Nmm)
(MPa)
(mm)
(MPa)
(Nmm2)
Fraksi volume
20%
803,575
85,61409
3,5873
1874,33529
18814,76883
Fraksi volume
30%
2072,55
1,27
5114,59448
123254,4682
Fraksi volume
40%
1577,225
99,39187
1,219
4654,64397
100316,1956
Fraksi volume
50%
2519,5
101,85879
1,4343
3292,70595
136747,1912
Jenis
Komposit
120,4369
68
Jenis
Komposit
Fraksi
volume
20%
Fraksi
volume
30%
Fraksi
volume
40%
Fraksi
volume
50%
Momen
Bending
Rata-rata
Tegangan
Bending
Rata-rata
Defleksi
Bending
Rata-rata
(Nmm)
(MPa)
(mm)
Modulus
Elastisitas
Bending
Rata-rata
(MPa)
1470,833
64,5698
2,984
3048,1183
107484,7506
1428,5416
36,2652
2,973
1187,4769
99578,8228
3560,1666
123,2598
2,771
5092,3261
267131,7309
2293,5416
53,68071
1,954
2623,5904
244927,5693
Kekakuan
Bending
Rata-rata
(Nmm2)
Momen
Bending
Rata-rata
Tegangan
Bending
Rata-rata
Defleksi
Bending
Rata-rata
(Nmm)
(MPa)
(mm)
Modulus
Elastisitas
Bending
Rata-rata
(MPa)
Fraksi
volume 20%
2271,208
55,28018
2,863
3312,1658
293203,8556
Fraksi
volume 30%
3111,983
66,56700
2626,6752
285747,1332
Fraksi
volume 40%
2740,995
40,70235
4,292
1243,2007
227115,3075
Fraksi
volume 50%
4618,3041
81,56316
3,349
3606,1574
533366,1163
Jenis
Komposit
3,859
Kekakuan
Bending
Rata-rata
(Nmm2)
69
Momen
Bending
Rata-rata
Tegangan
Bending
Rata-rata
Defleksi
Bending
Rata-rata
(Nmm)
(MPa)
(mm)
2093,733
30,67423
9,185
3393,2
56,91016
Jenis
Komposit
Fraksi
volume
20%
Fraksi
volume
30%
Fraksi
volume
40%
Fraksi
volume
50%
4394,533
7243,866
60,52086
70,23699
9,183
7,545
5,276
Modulus
Elastisitas
Bending
Rata-rata
(MPa)
660,8281
Kekakuan
Bending
Rata-rata
(Nmm2)
126236,8127
1297,2945
203167,9703
1513,6803
316967,853
2034,2484
731965,123
(mm4)
8000
7243,8666
7000
6000
5000
4618,304167
4000
3000
2519,5
2293,541667
2000
1000
417,9993333
0
0%
10%
20%
30%
40%
50%
60%
Fraksi volume
(%)
Tebal 1mm
Tebal 2mm
Tebal 3mm
Tebal 4mm
Tebal 5mm
dengan fraksi volume terhadap tebal komposit
70
(MPa)
140
120
100
101,8587993
80
81,56316509
70,23699981
60
53,68071386
52,15256141
40
20
0
0%
10%
20%
30%
40%
50%
60%
Fraksi volume
(%)
Tebal 1mm
Tebal 2mm
Tebal 3mm
Tebal 4mm
Tebal 5mm
Gambar 4.12. Grafik hubungan tegangan bending rata-rata
(mm)
10
8
6
5,276
4
3,349
2,426
1,954
1,434
2
0
0%
10%
20%
30%
40%
50%
60%
Fraksi volume
(%)
Tebal 1mm
Tebal 2mm
Tebal 3mm
Tebal 4mm
Tebal 5mm
(MPa)
71
6000
5000
4000
3606,157415
3292,705955
3000
2000
2623,590426
2034,248473
1000
1193,805941
0
0%
10%
20%
30%
40%
50%
60%
Fraksi volume
(%)
Tebal 1mm
Tebal 2mm
Tebal 3mm
Tebal 4mm
Tebal 5mm
Gambar 4.14. Grafik hubungan modulus elastisitas bending
rata-rata dengan fraksi volume terhadap tebal komposit
(N/mm2)
800000
731965,1235
700000
600000
533366,1163
500000
400000
300000
244927,5693
200000
136747,1912
100000
9225,10121
0
0%
10%
20%
30%
40%
50%
60%
Fraksi volume
(%)
Tebal 1mm
Tebal 2mm
Tebal 3mm
Tebal 4mm
Tebal 5mm
72
4.1.3.1
20%, Vf 30%, Vf 40% yaitu 35,0543 MPa, 30,3453 MPa,
45,8119 MPa. Pada spesimen tebal 2mm Vf 30% (120,4369),
99,39187 MPa, 101,85879 MPa. Pada spesimen tebal 3mm Vf
40% (123,2598 MPa), lebih besar dari Vf 20%, Vf 30%, Vf 50%
Sedangkan
modulus
elastisitas
rata-rata
tertinggi
73
782,0684 MPa, 396,2280 MPa, 647,4459 MPa. Pada spesimen
tebal 2mm Vf 30% (5114,59448 MPa), lebih besar dari Vf 20%,
Vf 40%, Vf 50%
3292,70595
MPa.
yaitu 1874,33529 MPa, 4654,64397 MPa,
Pada
spesimen
tebal
3mm
Vf
40%
3048,1183 MPa, 1187,4769 MPa, 2623,5904 MPa. Pada
MPa, 1297,2945 MPa, 1513,6803 MPa. Dari data-data yang
telah diperoleh harga modulus elastisitas bending optimal yaitu
pada spesimen tebal 2mm Vf 30% sebesar 5114,59448 MPa.
74
Jenis
Komposit
Fraksi
volume
20%
Fraksi
volume
30%
Fraksi
volume
40%
Fraksi
volume
50%
Momen
Bending
Ratarata
(Nmm)
Tegangan
Bending
Rata-rata
(MPa)
Defleksi
Bending
Ratarata
(mm)
Modulus
Elastisitas
Bending
Rata-rata
(MPa)
Kekakuan
Bending
Rata-rata
2
(Nmm )
130,662
34,32639
4,125
724,95737
1846,08538
281,029
49,80113
5,539
567,14517
2696,24404
385,953
34,19423
3,308
505,05016
6476,82875
632,544
78,03006
2,102
2093,29932
16217,37964
Jenis
Komposit
Fraksi
volume
20%
Fraksi
volume
30%
Fraksi
volume
40%
Fraksi
volume
50%
(MPa)
Defleksi
Bending
Ratarata
(mm)
Modulus
Elastisitas
Bending
Rata-rata
(MPa)
575,150
61,39330
2,354
1885,20806
18728,78645
686,125
40,02084
1,961
1133,19314
27570,30099
1428,825
89,39942
1,505
3267,25884
71414,83031
2004,075
80,97404
2,190
1638,91647
68252,33662
Momen
Bending
Rata-rata
Tegangan
Bending
Rata-rata
(Nmm)
Kekakuan
Bending
Rata-rata
2
(Nmm )
75
Jenis
Komposit
Fraksi
volume
20%
Fraksi
volume
30%
Fraksi
volume
40%
Fraksi
volume
50%
(MPa)
Defleksi
Bending
Ratarata
(mm)
Modulus
Elastisitas
Bending
Rata-rata
(MPa)
577,875
27,35307
1,780
2022,62093
67304,49059
1257,666
32,79411
2,296
1390,64183
118680,8508
2620,166
86,76242
3,297
3176,77790
179245,5071
4282,166
102,10968
1,736
5474,08931
507225,0836
Momen
Bending
Rata-rata
Tegangan
Bending
Rata-rata
(Nmm)
Kekakuan
Bending
Rata-rata
2
(Nmm )
Momen
Bending
Rata-rata
Tegangan
Bending
Rata-rata
Defleksi
Bending
Ratarata
Modulus
Elastisitas
Bending
Rata-rata
Kekakuan
Bending
Rata-rata
(Nmm)
(MPa)
(mm)
(MPa)
(Nmm )
Fraksi
volume
20%
1889,442
45,44886
3,595
2121,48961
191138,151
Fraksi
volume
30%
2755,837
58,92963
1506,94289
164344,4337
Fraksi
volume
40%
3723,579
55,59110
4,449
1635,84638
299174,4884
Fraksi
volume
50%
4956,520
87,83150
4,289
2907,42209
416628,8935
Jenis
Komposit
6,045
2
76
Jenis
Komposit
Fraksi
volume
20%
Fraksi
volume
30%
Fraksi
volume
40%
Fraksi
volume
50%
(MPa)
Defleksi
Bending
Ratarata
(mm)
Modulus
Elastisitas
Bending
Rata-rata
(MPa)
2203,067
31,59097
4,467
1423,26882
268821,8254
3671,933
61,47096
7,837
1602,08804
253191,2614
5587,133
76,34464
5,047
2757,31646
581851,329
4596,533
44,66811
5,184
1313,34294
470505,990
Momen
Bending
Rata-rata
Tegangan
Bending
Rata-rata
(Nmm)
Kekakuan
Bending
Rata-rata
2
(Nmm )
(mm4)
6000
5000
4956,521
4596,533
4282,167
4000
3000
2000
2004,075
1000
632,5447
0
0%
10%
20%
30%
40%
50%
60%
Fraksi volume
(%)
Tebal 1mm
Tebal 2mm
Tebal 3mm
Tebal 4mm
Tebal 5mm
77
(MPa)
120
100
102,109681
80
87,8315065
80,9740418
78,030065
60
44,6681165
40
20
0
0%
10%
20%
30%
40%
50%
60%
Fraksi volume
(%)
Tebal 1mm
Tebal 2mm
Tebal 3mm
Tebal 4mm
Tebal 5mm
Gambar 4.17. Grafik hubungan tegangan bending rata-rata
(mm)
9
8
7
6
5
4
3
2
1
0
5,184
4,289
2,19
2,102
1,736
0%
10%
20%
30%
40%
50%
60%
Fraksi volume
(%)
Tebal 1mm
Tebal 2mm
Tebal 3mm
Tebal 4mm
Tebal 5mm
Gambar 4.18. Grafik hubungan defleksi bending rata-rata
(MPa)
78
6000
5474,08931
5000
4000
3000
2907,4221
2000
2093,29933
1638,91647
1313,34295
1000
0
0%
10%
20%
30%
40%
50%
60%
Fraksi volume
(%)
Tebal 1mm
Tebal 2mm
Tebal 3mm
Tebal 4mm
Tebal 5mm
Gambar 4.19. Grafik hubungan modulus elastisitas bending
(N/mm2)
rata-rata dengan fraksi volume terhadap tebal komposit.
700000
600000
507225,0836
470505,9907
416628,8935
500000
400000
300000
200000
100000
68252,33662
16217,37964
0
0%
10%
20%
30%
40%
50%
60%
Fraksi volume
(%)
Tebal 1mm
Tebal 2mm
Tebal 3mm
Tebal 4mm
Tebal 5mm
Gambar 4.20. Grafik hubungan kekakuan bending rata-rata
79
4.1.4.1
34,19423 MPa. Pada spesimen tebal 2mm Vf 40% (89,39942),
40,02084 MPa, 80,97404 MPa. Pada spesimen tebal 3mm Vf
50% (102,10968 MPa), lebih besar dari Vf 20%, Vf 30%, Vf 40%
Sedangkan
modulus
elastisitas
rata-rata
tertinggi
80
spesimen tebal 2mm Vf 40% (3267,25884 MPa), lebih besar
dari Vf 20%, Vf 30%, Vf 50%
yaitu 1885,20806 MPa,
40%
yaitu 2022,62093 MPa, 1390,64183 MPa, 3176,77790
MPa. Pada spesimen tebal 4mm Vf 50% (2907,42209 MPa),
50%
yaitu 1423,26882 MPa, 1602,08804 MPa, 1313,34294
MPa. Dari data-data yang telah diperoleh harga modulus
elastisitas bending optimal yaitu pada spesimen tebal 3mm Vf
50% sebesar 5474,089311 MPa.
81
4.2.
Pengujian Tarik
4.2.1 Data Hasil Pengujian Tarik Rata-rata Pada Alkali 2 Jam
Tabel 4.21. Hasil Data Pengujian Tarik Alkali 2 Jam
Spesimen
Kekuatan Tarik Rata-Rata
Modulus Elastisitas Rata-Rata
20 % T1
0.662
0.797
30 % T1
0.772
0.850
40 % T1
0.906
1.174
50 % T1
1.506
1.747
20 % T2
1.348
3.297
30 % T2
1.994
4.060
40 % T2
2.523
4.875
50 % T2
3.192
5.565
20 % T3
2.193
5.924
30 % T3
3.032
6.756
40 % T3
4.686
28.560
50 % T3
5.941
9.449
20 % T4
4.353
5.208
30 % T4
3.714
5.899
40 % T4
6.018
4.782
50 % T4
11.710
9.069
20 % T5
8.399
5.884
30 % T5
8.377
5.462
40 % T5
9.423
6.341
50 % T5
12.644
8.731
Modulus Elastisitas Tarik Rata-rata
(MPa)
82
30
25
20
15
8,731
10
9,069
5,565
1,747
5
0
0
10
Tebal 1 mm
20
Tebal 2 mm
30
40
Fraksi Volume
(%)
Tebal 3 mm
50
60
Tebal 4 mm
Tebal 5 mm
Gambar 4.21. Grafik hubungan modulus elastisitas tarik ratarata dengan fraksi volume terhadap tebal komposit
Kekuatan Tarik Rata-rata
(MPa)
14
12,644
11,710
12
10
8
6
5,941
4
3,192
1,506
2
0
0
Tebal 1mm
10
Tebal 2mm
20
30
Fraksi Volume
(%)
Tebal 3mm
40
50
Tebal 4mm
60
Tebal 5mm
Gambar 4.22. Grafik hubungan kekuatan tarik rata-rata dengan
83
4.2.1.1 Pembahasan Pengujian Tarik Alkali 2 Jam
Dari hasil pengujian tarik didapatkan harga yang paling
optimal pada tebal 5mm Vf 50% yaitu sebesar 12,644 MPa,
sedangkan yang terendah adalah komposit serat rami dengan Vf
20% pada tebal 1mm yang mempunyai harga tarik rata- rata 0,662
MPa. Hal ini dipengaruhi oleh fraksi volume dan ketebalan
spesimen, semakin tebal dan fraksi meningkat maka harga
kekuatan tarik meningkat.
Sedangkan untuk Modulus elastisitas tertinggi pada tebal
3mm fraksi volume 40% yaitu sebesar 28,560 MPa,sedangkan
terendah adalah pada spesimen fraksi volume 20% ketebalan 1mm
yaitu 0,797 MPa.
84
Spesimen
20 % T1
0,798
0,878
30 % T1
0,755
0,956
40 % T1
1,868
1,498
50 % T1
1,483
2,025
20 % T2
1,806
3,308
30 % T2
1,663
1,563
40 % T2
3,354
4,921
50 % T2
4,769
7,103
20 % T3
2,845
6,928
30 % T3
3,787
5,942
40 % T3
3,155
6,049
50 % T3
7,613
10,019
20 % T4
4,680
8,275
30 % T4
4,972
7,385
40 % T4
4,852
9,222
50 % T4
6,983
8,919
20 % T5
2,992
7,659
30 % T5
4,530
9,801
40 % T5
4,988
8,909
50 % T5
9,581
12,244
(MPa)
85
14
12
12,244
10
10,019
8,919
8
6
7,103
6,049
4
2
2,025
0
0
10
20
30
40
50
60
Fraksi Volume
(%)
Tebal 1 mm
Tebal 2 mm
Tebal 3 mm
Tebal 4 mm
Tebal 5 mm
Gambar 4.23. Grafik hubungan modulus elastisitas tarik rata-
(MPa)
rata dengan fraksi volume terhadap tebal komposit
12
10
9,581
8
7,613
6,983
6
4,769
4
2
1,483
0
0
Tebal 1mm
10
Tebal 2mm
20
30
Fraksi Volume
(%)
Tebal 3mm
40
50
Tebal 4mm
60
Tebal 5mm
86
MPa.
5mm fraksi
volume 50% yaitu sebesar 12,244 MPa,sedangkan
yaitu 0,878 MPa.
87
Tabel 4.23. Hasil Data Pengujian Tarik Alkali 6 Jam.
Spesimen
20 % T1
0,601
0,886
30 % T1
1,059
1,128
40 % T1
1,388
1,568
50 % T1
2,352
3,096
20 % T2
1,856
2,700
30 % T2
1,971
5,536
40 % T2
4,824
7,293
50 % T2
5,164
5,205
20 % T3
2,738
5,420
30 % T3
3,350
7,040
40 % T3
4,920
6,533
50 % T3
6,740
9,554
20 % T4
3,402
7,451
30 % T4
5,379
9,314
40 % T4
6,604
8,290
50 % T4
5,357
8,917
20 % T5
4,270
8,504
30 % T5
5,858
9,652
40 % T5
6,465
7,410
50 % T5
10,091
11,638
(MPa)
88
14
12
11,638
10
9,554
8,917
8
6
5,205
4
3,096
2
0
0
10
20
30
40
50
60
Fraksi Volume
(%)
Tebal 1 mm
Tebal 2 mm
Tebal 3 mm
Tebal 4 mm
Tebal 5 mm
Gambar 4.25. Grafik hubungan modulus elastisitas tarik ratarata dengan fraksi volume terhadap tebal komposit
(MPa)
12
10,091
10
8
6,740
5,357
5,164
6
4
2,352
2
0
0
Tebal 1mm
10
Tebal 2mm
20
30
Fraksi Volume
(%)
Tebal 3mm
40
50
Tebal 4mm
60
Tebal 5mm
89
MPa.
5mm fraksi
yaitu 0,886 MPa.
90
Spesimen
20 % T1
0,604
0,895
30 % T1
1,222
1,908
40 % T1
1,132
1,213
50 % T1
1,788
3,309
20 % T2
1,448
2,825
30 % T2
2,262
4,441
40 % T2
3,663
6,784
50 % T2
3,785
6,919
20 % T3
2,684
5,557
30 % T3
3,307
5,657
40 % T3
4,272
6,898
50 % T3
7,751
9,318
20 % T4
3,323
7,485
30 % T4
4,131
7,596
40 % T4
5,713
10,160
50 % T4
10,062
8,705
20 % T5
5,679
12,173
30 % T5
6,093
11,420
40 % T5
7,931
11,122
50 % T5
7,174
10,558
(MPa)
91
14
12
10,558
9,318
8,705
10
8
6,919
6
4
3,309
2
0
0
10
20
30
40
50
60
Fraksi Volume
(%)
Tebal 1 mm
Tebal 2 mm
Tebal 3 mm
Tebal 4 mm
Tebal 5 mm
Gambar 4.27. Grafik hubungan modulus elastisitas tarik rata-
(MPa)
rata dengan fraksi volume terhadap tebal komposit
12
10
10,062
8
7,751
7,174
6
4
3,785
2
1,788
0
0
Tebal 1mm
10
Tebal 2mm
20
30
Fraksi Volume
(%)
Tebal 3mm
40
50
Tebal 4mm
60
Tebal 5mm
92
MPa.
5mm fraksi
yaitu 0,895 MPa.
93
4.3.
Pengujian Impak
4.3.1. Data Hasil Pengujian Impak Rata-rata Pada Alkali 2 Jam
Tabel 4.25. Hasil Data Pengujian Impak Alkali 2 Jam
Spesimen
Kekuatan Impak RataRata
Energi yang terserap Rata-rata
20 % T1
0,433
2,522
30 % T1
0,467
3,761
40 % T1
0,700
7,016
50 % T1
0,733
7,289
20 % T2
0,867
9,254
30 % T2
0,767
12,047
40 % T2
0,600
9,716
50 % T2
0,967
18,619
20 % T3
1,067
17,757
30 % T3
1,133
21,379
40 % T3
1,167
23,307
50 % T3
1,067
23,421
20 % T4
1,433
29,375
30 % T4
1,133
28,023
40 % T4
1,267
32,180
50 % T4
1,500
35,908
20 % T5
1,667
47,014
30 % T5
1,633
45,242
40 % T5
1,733
48,920
50 % T5
1,700
48,555
94
2
Harga impak rata-rata
(J/mm2)
1,8
1,7
1,6
1,5
1,4
1,2
1,067
0,967
1
0,8
0,733
0,6
0,4
0,2
0
0%
10%
20%
30%
40%
50%
60%
Fraksi volume
(%)
Tebal 1mm
Tebal 2mm
Tebal 3mm
Tebal 4mm
tebal 5mm
Gambar 4.29. Grafik hubungan Harga Impak rata-rata dengan
Energi terserap impak rata-rata
(J/mm2)
60
50
48,555
40
35,908
30
23,421
18,619
20
10
7,289
0
0%
10%
20%
30%
40%
50%
60%
Fraksi volume
(%)
Tebal 1mm
Tebal 2mm
Tebal 3mm
Tebal 4mm
Tebal 5mm
Gambar 4.30. Grafik Hubungan Energi Serap Impak Rata-rata
dengan Fraksi Volume Terhadap Tebal Komposit.
95
4.3.1.1 Pembahasan Pengujian Impak Dengan Alkali 2 Jam
Dari hasil pengujian Impak didapatkan harga yang paling
optimal pada Vf 40% dengan tebal 5mm yaitu sebesar 1,733 J/mm2
20% pada tebal 1mm yang mempunyai harga Impak rata- rata
0,433 J/mm². Hal ini dipengaruhi oleh luasan daerah Impak semakin
luas daerah Impak semakin kecil pula harga Impak komposit
tersebut.
Dan energi terserap Impak yang paling tinggi pada Vf 40%
dengan tebal 5mm yaitu sebesar 48,920 J/mm2 sedangkan yang
terendah adalah komposit serat rami dengan Vf 20% pada tebal
1mm yang mempunyai harga Impak rata- rata 2,522 J/mm².
96
Spesimen
20 % T1
0,500
3,188
30 % T1
0,533
4,343
40 % T1
0,700
7,428
50 % T1
0,767
7,578
20 % T2
0,833
8,869
30 % T2
0,800
12,586
40 % T2
0,700
11,254
50 % T2
1,000
19,304
20 % T3
1,133
18,873
30 % T3
1,233
23,236
40 % T3
1,067
21,357
50 % T3
1,433
31,457
20 % T4
1,467
30,026
30 % T4
1,233
30,384
40 % T4
1,533
38,947
50 % T4
1,567
37,683
20 % T5
1,467
41,267
30 % T5
1,633
45,155
40 % T5
1,767
49,961
50 % T5
1,767
50,555
(J/mm2)
97
2
1,8
1,6
1,4
1,2
1
0,8
0,6
0,4
0,2
0
1,767
1,567
1,433
1
0,767
0%
10%
20%
30%
40%
50%
60%
Fraksi volume
(%)
Tebal 1mm
Tebal 2mm
Tebal 3mm
Tebal 4mm
Tebal 5mm
Gambar 4.31. Grafik hubungan Harga Impak rata-rata dengan fraksi
(J/mm2)
60
50,555
50
40
30
37,683
31,457
20
19,304
10
7,578
0
0%
10%
20%
30%
40%
50%
60%
Fraksi volume
(%)
Tebal 1mm
Tebal 2mm
Tebal 3mm
Tebal 4mm
Tebal 5mm
Gambar 4.32. Grafik Hubungan Energi Serap Impak Rata-rata dengan
Fraksi Volume Terhadap Tebal Komposit.
98
optimal pada Vf 40% dan Vf 50% dengan tebal 5mm yaitu sebesar
1,767 J/mm2 sedangkan yang terendah adalah komposit serat rami
dengan Vf 20% pada tebal 1mm yang mempunyai harga Impak ratarata 0,500 J/mm².
99
Spesimen
20 % T1
0,533
3,206
30 % T1
0,500
3,998
40 % T1
0,600
5,669
50 % T1
0,700
6,962
20 % T2
0,900
9,562
30 % T2
0,733
11,541
40 % T2
0,800
12,506
50 % T2
1,133
15,720
20 % T3
1,000
16,701
30 % T3
1,267
23,711
40 % T3
1,267
25,206
50 % T3
1,333
29,245
20 % T4
1,233
25,240
30 % T4
1,267
31,399
40 % T4
1,533
38,979
50 % T4
1,733
41,514
20 % T5
1,567
44,231
30 % T5
1,667
46,135
40 % T5
1,700
48,132
50 % T5
1,833
52,704
(J/mm2)
100
2
1,8
1,6
1,4
1,2
1
0,8
0,6
0,4
0,2
0
1,833
1,733
1,333
1,133
0,7
0%
10%
20%
30%
40%
50%
60%
Fraksi volume
(%)
Tebal 1mm
Tebal 2mm
Tebal 3mm
Tebal 4mm
Tebal 5mm
(J/mm2)
60
52,704
50
40
41,514
30
29,245
20
15,72
10
6,962
0
0%
10%
20%
30%
40%
50%
60%
Fraksi volume
(%)
Tebal 1mm
Tebal 2mm
Tebal 3mm
Tebal 4mm
Tebal 5mm
Fraksi Volume Terhadap Tebal Komposit.
101
30% pada tebal 1mm yang mempunyai harga Impak rata- rata
0,500 J/mm².
102
Spesimen
20 % T1
0,533
3,273
30 % T1
0,533
4,409
40 % T1
0,667
6,045
50 % T1
0,800
7,949
20 % T2
0,833
8,904
30 % T2
0,967
15,213
40 % T2
0,767
11,922
50 % T2
0,933
12,997
20 % T3
1,133
18,873
30 % T3
1,167
21,833
40 % T3
1,233
24,468
50 % T3
1,367
29,980
20 % T4
1,133
23,191
30 % T4
1,433
35,444
40 % T4
1,433
36,438
50 % T4
1,700
40,737
20 % T5
1,633
46,026
30 % T5
1,600
44,432
40 % T5
1,667
46,971
50 % T5
1,733
47,617
(J/mm2)
103
2
1,8
1,6
1,4
1,2
1
0,8
0,6
0,4
0,2
0
1,733
1,7
1,367
0,933
0,8
0%
10%
20%
30%
40%
50%
60%
Fraksi volume
(%)
Tebal 1mm
Tebal 2mm
Tebal 3mm
Tebal 4mm
Tebal 5mm
(J/mm2)
50
45
40
35
30
25
20
15
10
5
0
47,617
40,737
29,98
12,997
7,949
0%
10%
20%
30%
40%
50%
60%
Fraksi volume
(%)
Tebal 1mm
Tebal 2mm
Tebal 3mm
Tebal 4mm
Tebal 5mm
Fraksi Volume Terhadap Tebal Komposit
104
20%, 30% pada tebal 1mm yang mempunyai harga Impak rata- rata
0,533 J/mm².
1mm yang mempunyai harga Impak rata- rata 3,273 J/mm².Hal ini
dipengaruhi oleh fraksi volume dan ketebalan spesimen,semakin
tebal dan meningkatnya fraksi volume maka harga energi serapnya
meningkat.
105
4.4.
Pengamatan Stuktur Makro
Pengamatan struktur makro dilakukan pada bentuk patahan
benda uji. Berikut ini adalah data gambar-gambar foto patahan makro,
seperti ditunjukkan pada gambar:
1mm
1mm
Matrik
Serat rami
Vf 40% 3mm 2 jam
1mm
1mm
Vf 40% 2mm 4 jam
Patahan akibat gaya
tekan
1mm
Patahan akibat gaya
tarik
Patahan akibat gaya tekan
Patahan akibat gaya tarik
Vf 40% 3mm 6 jam
Vf 50% 3mm 8 jam
an
Gambar 4.37.Contoh Patahan Spesimen pada Uji Bending dengan
perbedaan waktu alkali.
1mm
Broken fiber
Serat rami
Kegagalan
akibat patah
getas
Matrik
Vf 40% 5mm 2 jam
106
1mm
Vf 40% 5mm 4 jam
1mm
Vf 50% 5mm 6 jam
1mm
Serat rami
Broken fiber
Kegagalan
akibat patah
getas
Matrik
Vf 50% 5mm 8 jam
Gambar 4.38.Contoh Patahan spesimen pada Uji Impak dengan
107
1mm
1mm
Vf 50% 5mm 2 jam
1mm
Vf 50% 5mm 4 jam
1mm
Matrik
Broken fiber
Serat rami
Vf 50% 5mm 6 jam
Vf 50% 4mm 8 jam
Gambar 4.39.Contoh Patahan spesimen pada Uji Tarik dengan
4.4.1. Pembahasan Foto Patahan
Dari hasi foto patahan dapat dilihat bahwa jenis patahan
yang terjadi adalah patahan jenis broken fiber. Patahan broken
fiber yaitu patahan pada spesimen dimana serat mengalami patah
108
atau rusak dan membentuk seperti serabut. Hal ini disebabkan
oleh distribusi matrik dengan serat kurang merata dan adanya void
di sekitar serat.
Pada bentuk patahan dapat disimpulkan bahwa jenis
patahan yang terjadi adalah patah getas. Arah dari perambatan
retak adalah tegak lurus dengan arah tegangan tarik yang bekerja
dan menghasilkan permukaan yang relatif rata.
109
BAB V
KESIMPULAN DAN SARAN
5.1.
KESIMPULAN
Dari hasil penelitian dan analisa pengujian serta pembahasan data
yang diperoleh, dapat disimpulkan:
1 Kekuatan bending rata-rata komposit serat (fibrous composite)
serat rami acak dengan perlakuan alkali 2 jam,4 jam,6 jam dan 8
jam yang optimal yaitu :
 Pada alkali 2 jam tebal 3mm Vf 40% sebesar 143,9594 MPa.
Dari data-data yang telah diperoleh menunjukkan harga
kekuatan bending yang paling optimal yaitu pada alkali 2 jam
tebal spesimen 3mm Vf 40% yaitu sebesar 143,9594 MPa.
2 Untuk harga tarik rata-rata komposit serat (fibrous composite)
109
110
Dari data-data yang telah diperoleh harga tarik yang
paling optimal komposit serat rami acak yaitu pada alkali 2 jam
tebal 5mm Vf 50% sebesar 12,644 MPa.
3 Kekuatan impak rata-rata komposit serat (fibrous composite)
 Pada alkali 2 jam tebal 5mm Vf 40% sebesar 1,733 J/mm2
Dari data-data yang telah diperoleh menunjukkan harga
kekuatan impak yang paling optimal yaitu pada alkali 6 jam tebal
spesimen 5mm Vf 50% yaitu sebesar 1,833 J/mm2
4
Pengamatan Foto Makro
Dari hasi foto patahan dapat dilihat bahwa jenis patahan
yang terjadi adalah patahan jenis broken fiber. Patahan broken
fiber yaitu patahan pada spesimen dimana serat mengalami
patah atau rusak dan membentuk seperti serabut.
Pada bentuk patahan dapat disimpulkan bahwa jenis
patahan yang terjadi adalah patah getas. Arah dari perambatan
retak adalah tegak lurus dengan arah tegangan tarik yang
bekerja dan menghasilkan permukaan yang relatif rata.
111
5.2.
SARAN
Dari hasil proses percetakan ada beberapa hal yang perlu
diperhatikan, diantaranya:
1 Pada proses pembuatan serat acak hendaknya serat disusun
merata agar
memudahkan pencetakan,dan menghasilkan
cetakan komposit yang tebalnya sama dalam satu bidang.
2 Meminimalkan keberadaan rongga udara (void) pada komposit
yang akan dibuat sehingga akan menaikkan kekuatan komposit
dengan menggunakan alat tekan yang lebih baik.
3 Dalam melakukan pembuatan benda uji hendaknya memakai
alat pengaman, karena bahan benda uji merupakan bahan
kimia.
4 Pada proses penuangan matrik kedalam serat harus merata
dan cepat
agar serat benar-benar terbungkus oleh matrik,
sehingga dapat meminimalkan terjadinya void.
5 Dalam melakukan pengujian hendaknya dilakukan sendiri agar
kita mengetahui proses pengujian tersebut.
DAFTAR PUSTAKA
ASTM. D 790 – 02 Standard test methods for flexural properties of
unreinforced and reinforced plastics and electrical insulating material.
Philadelphia, PA : American Society for Testing and Materials.
ASTM. D 570 – 98 Standard test method for water absorption of plastics.
ASTM. D 256 – 00 Standard test methods for determining the izod
pendulum impact resistance of plastics.
ASTM. D 638-02 Standart test method for tensile properties of plastics.
Callister, W. D., 2007, Material Science and Enginering, An Introduction
7ed, Department of Metallurgical Enginering The University of Utah,
John Willey and Sons, Inc.
Diharjo, K., dan Triyono, T., 2003, Buku Pegangan Kuliah Material Teknik,
Universitas Sebelas Maret, Surakarta.
Fajar, S.N., 2008, Optimasi Kekuatan Bending Dan Impact Komposit
Berpenguat Serat Ramie Bermatrik Polyester Bqtn 157 Terhadap
Fraksi Volume Dan Tebal Skin
Gibson, 1994.Principle Of Composite Material Mechanics. New York : Mc
Graw Hill,Inc.
Nurkholis., 2008, Analisis Sifat Tarik dan Impak Komposit Serat Rami
Dengan Perlakuan Alkali Dalam Waktu 2, 4, 6, dan 8 jam, Fraksi
Volume Serat 10% Dengan Matrik Poliester BQTN 157.
Harper, A. C., 1996, Handbook of Plastics, Elastomers and Composites,
Mc Graw Hill Componies, Inc.
Jones, M. R., 1975, Mechanics of Composite Material, Mc Graww Hill
Kogakusha, Ltd.
Junaedi, 2008, Penelitian Kekuatan Tarik dan Impak Komposit
Serat Rami Dengan Variasi Panjang Serat 25mm, 50mm, dan
100mm, Dengan Fraksi Volume Serat 10% Dengan Matrik Poliester
BQTN 157.
Lukkassen, Dag dan Annette Meidell. 13 Oktober 2003. Advanced
Materials and Structures and their Fabrication Processes, edisi III.
HiN: NarvikUniversity College.
Mueler, Dieter H. October 2003. New Discovery in the Properties of
Composites Reinforced with Natural Fibers. JOURNAL OF
INDUSTRIAL TEXTILES, Vol. 33, No. 2. Sage Publications.
Nanang, 2006, Penelitian Kekuatan Bending Dan Impak Komposit Serat
Kenaf Tanpa Perlakuan Alkali Dengan Fraksi Volume Serat 10%, 15%
dan 20% Dengan Matrik Poliester.
Saprudin, 2004, Penelitian Kekuatan Bending dan Impak Komposit Serat
Kenaf Tanpa Perlakuan Alkali Dengan Fraksi Volume Serat 30% dan
40%.
Surdia, 1992, Pengetahuan Bahan Teknik, FT, Pradnaya Paramita,
Jakarta.
Van Vlack, 2005, Ilmu dan Teknologi Bahan, Erlangga Jakarta.
http://www.kemahasiswaan.its.ac.id.pdf : 15 Januari 2008
http://www.iptek.net.id/ind/?mnu=8&ch=jsti&id=115 : 20 Agustus 2008
http://www.gatra.com/2006-01-01/versi_cetak.php?id=91072 : 20 Agustus
2008
An American National Standard
Designation: D 638 – 02
Standard Test Method for
Tensile Properties of Plastics1
This standard is issued under the fixed designation D 638; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
1.6 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
1. Scope *
1.1 This test method covers the determination of the tensile
properties of unreinforced and reinforced plastics in the form
of standard dumbbell-shaped test specimens when tested under
defined conditions of pretreatment, temperature, humidity, and
testing machine speed.
1.2 This test method can be used for testing materials of any
thickness up to 14 mm (0.55 in.). However, for testing
specimens in the form of thin sheeting, including film less than
1.0 mm (0.04 in.) in thickness, Test Methods D 882 is the
preferred test method. Materials with a thickness greater than
14 mm (0.55 in.) must be reduced by machining.
1.3 This test method includes the option of determining
Poisson’s ratio at room temperature.
2. Referenced Documents
2.1 ASTM Standards:
D 229 Test Methods for Rigid Sheet and Plate Materials
Used for Electrical Insulation2
D 412 Test Methods for Vulcanized Rubber and Thermoplastic Elastomers—Tension3
D 618 Practice for Conditioning Plastics for Testing4
D 651 Test Method for Tensile Strength of Molded Electrical Insulating Materials5
D 882 Test Methods for Tensile Properties of Thin Plastic
Sheeting4
D 883 Terminology Relating to Plastics4
D 1822 Test Method for Tensile-Impact Energy to Break
Plastics and Electrical Insulating Materials4
D 3039/D 3039M Test Method for Tensile Properties of
Polymer Matrix Composite Materials6
D 4000 Classification System for Specifying Plastic Materials7
D 4066 Classification System for Nylon Injection and Extrusion Materials7
D 5947 Test Methods for Physical Dimensions of Solid
Plastic Specimens8
E 4 Practices for Force Verification of Testing Machines9
E 83 Practice for Verification and Classification of Extensometer9
E 132 Test Method for Poisson’s Ratio at Room Temperature9
E 691 Practice for Conducting an Interlaboratory Study to
NOTE 1—This test method and ISO 527-1 are technically equivalent.
NOTE 2—This test method is not intended to cover precise physical
procedures. It is recognized that the constant rate of crosshead movement
type of test leaves much to be desired from a theoretical standpoint, that
wide differences may exist between rate of crosshead movement and rate
of strain between gage marks on the specimen, and that the testing speeds
specified disguise important effects characteristic of materials in the
plastic state. Further, it is realized that variations in the thicknesses of test
specimens, which are permitted by these procedures, produce variations in
the surface-volume ratios of such specimens, and that these variations may
influence the test results. Hence, where directly comparable results are
desired, all samples should be of equal thickness. Special additional tests
should be used where more precise physical data are needed.
NOTE 3—This test method may be used for testing phenolic molded
resin or laminated materials. However, where these materials are used as
electrical insulation, such materials should be tested in accordance with
Test Methods D 229 and Test Method D 651.
NOTE 4—For tensile properties of resin-matrix composites reinforced
with oriented continuous or discontinuous high modulus >20-GPa
(>3.0 3 106-psi) fibers, tests shall be made in accordance with Test
Method D 3039/D 3039M.
1.4 Test data obtained by this test method are relevant and
appropriate for use in engineering design.
1.5 The values stated in SI units are to be regarded as the
standard. The values given in parentheses are for information
only.
2
Annual Book of ASTM Standards, Vol 10.01.
4
5
Discontinued; see 1994 Annual Book of ASTM Standards, Vol 10.01.
6
7
8
9
3
1
This test method is under the jurisdiction of ASTM Committee D20 on Plastics
and is the direct responsibility of Subcommittee D20.10 on Mechanical Properties.
Current edition approved April 10, 2002. Published June 2002. Originally
published as D 638 – 41 T. Last previous edition D 638 – 01.
*A Summary of Changes section appears at the end of this standard.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
1
D 638
Determine the Precision of a Test Method10
2.2 ISO Standard:
ISO 527-1 Determination of Tensile Properties11
modulus of the usually defined type. Such a constant is useful if its
arbitrary nature and dependence on time, temperature, and similar factors
are realized.
4.4 Poisson’s Ratio—When uniaxial tensile force is applied
to a solid, the solid stretches in the direction of the applied
force (axially), but it also contracts in both dimensions lateral
to the applied force. If the solid is homogeneous and isotropic,
and the material remains elastic under the action of the applied
force, the lateral strain bears a constant relationship to the axial
strain. This constant, called Poisson’s ratio, is defined as the
negative ratio of the transverse (negative) to axial strain under
uniaxial stress.
4.4.1 Poisson’s ratio is used for the design of structures in
which all dimensional changes resulting from the application
of force need to be taken into account and in the application of
the generalized theory of elasticity to structural analysis.
3. Terminology
3.1 Definitions—Definitions of terms applying to this test
method appear in Terminology D 883 and Annex A2.
4. Significance and Use
4.1 This test method is designed to produce tensile property
data for the control and specification of plastic materials. These
data are also useful for qualitative characterization and for
research and development. For many materials, there may be a
specification that requires the use of this test method, but with
some procedural modifications that take precedence when
adhering to the specification. Therefore, it is advisable to refer
to that material specification before using this test method.
Table 1 in Classification D 4000 lists the ASTM materials
standards that currently exist.
4.2 Tensile properties may vary with specimen preparation
and with speed and environment of testing. Consequently,
where precise comparative results are desired, these factors
must be carefully controlled.
4.2.1 It is realized that a material cannot be tested without
also testing the method of preparation of that material. Hence,
when comparative tests of materials per se are desired, the
greatest care must be exercised to ensure that all samples are
prepared in exactly the same way, unless the test is to include
the effects of sample preparation. Similarly, for referee purposes or comparisons within any given series of specimens,
care must be taken to secure the maximum degree of uniformity in details of preparation, treatment, and handling.
4.3 Tensile properties may provide useful data for plastics
engineering design purposes. However, because of the high
degree of sensitivity exhibited by many plastics to rate of
straining and environmental conditions, data obtained by this
test method cannot be considered valid for applications involving load-time scales or environments widely different from
those of this test method. In cases of such dissimilarity, no
reliable estimation of the limit of usefulness can be made for
most plastics. This sensitivity to rate of straining and environment necessitates testing over a broad load-time scale (including impact and creep) and range of environmental conditions if
tensile properties are to suffice for engineering design purposes.
NOTE 6—The accuracy of the determination of Poisson’s ratio is
usually limited by the accuracy of the transverse strain measurements
because the percentage errors in these measurements are usually greater
than in the axial strain measurements. Since a ratio rather than an absolute
quantity is measured, it is only necessary to know accurately the relative
value of the calibration factors of the extensometers. Also, in general, the
value of the applied loads need not be known accurately.
5. Apparatus
5.1 Testing Machine—A testing machine of the constantrate-of-crosshead-movement type and comprising essentially
the following:
5.1.1 Fixed Member—A fixed or essentially stationary
member carrying one grip.
5.1.2 Movable Member—A movable member carrying a
second grip.
5.1.3 Grips—Grips for holding the test specimen between
the fixed member and the movable member of the testing
machine can be either the fixed or self-aligning type.
5.1.3.1 Fixed grips are rigidly attached to the fixed and
movable members of the testing machine. When this type of
grip is used extreme care should be taken to ensure that the test
specimen is inserted and clamped so that the long axis of the
test specimen coincides with the direction of pull through the
center line of the grip assembly.
5.1.3.2 Self-aligning grips are attached to the fixed and
movable members of the testing machine in such a manner that
they will move freely into alignment as soon as any load is
applied so that the long axis of the test specimen will coincide
with the direction of the applied pull through the center line of
the grip assembly. The specimens should be aligned as perfectly as possible with the direction of pull so that no rotary
motion that may induce slippage will occur in the grips; there
is a limit to the amount of misalignment self-aligning grips will
accommodate.
5.1.3.3 The test specimen shall be held in such a way that
slippage relative to the grips is prevented insofar as possible.
Grip surfaces that are deeply scored or serrated with a pattern
similar to those of a coarse single-cut file, serrations about 2.4
mm (0.09 in.) apart and about 1.6 mm (0.06 in.) deep, have
been found satisfactory for most thermoplastics. Finer serrations have been found to be more satisfactory for harder
plastics, such as the thermosetting materials. The serrations
NOTE 5—Since the existence of a true elastic limit in plastics (as in
many other organic materials and in many metals) is debatable, the
propriety of applying the term “elastic modulus” in its quoted, generally
accepted definition to describe the “stiffness” or “rigidity” of a plastic has
been seriously questioned. The exact stress-strain characteristics of plastic
materials are highly dependent on such factors as rate of application of
stress, temperature, previous history of specimen, etc. However, stressstrain curves for plastics, determined as described in this test method,
almost always show a linear region at low stresses, and a straight line
drawn tangent to this portion of the curve permits calculation of an elastic
10
Available from American National Standards Institute, 25 W. 43rd St., 4th
Floor, New York, NY 10036.
11
2
D 638
ments meets this requirement.
5.2.2 Low-Extension Measurements—For elongation-atyield and low-extension measurements (nominally 20 % or
less), the same above extensometer, attenuated to 20 % extension, may be used. In any case, the extensometer system must
meet at least Class C (Practice E 83) requirements, which
include a fixed strain error of 0.001 strain or 61.0 % of the
indicated strain, whichever is greater.
5.2.3 High-Extension Measurements—For making measurements at elongations greater than 20 %, measuring techniques with error no greater than 610 % of the measured value
are acceptable.
5.2.4 Poisson’s Ratio—Bi-axial extensometer or axial and
transverse extensometers capable of recording axial strain and
transverse strain simultaneously. The extensometers shall be
capable of measuring the change in strains with an accuracy of
1 % of the relevant value or better.
should be kept clean and sharp. Breaking in the grips may
occur at times, even when deep serrations or abraded specimen
surfaces are used; other techniques must be used in these cases.
Other techniques that have been found useful, particularly with
smooth-faced grips, are abrading that portion of the surface of
the specimen that will be in the grips, and interposing thin
pieces of abrasive cloth, abrasive paper, or plastic, or rubbercoated fabric, commonly called hospital sheeting, between the
specimen and the grip surface. No. 80 double-sided abrasive
paper has been found effective in many cases. An open-mesh
fabric, in which the threads are coated with abrasive, has also
been effective. Reducing the cross-sectional area of the specimen may also be effective. The use of special types of grips is
sometimes necessary to eliminate slippage and breakage in the
grips.
5.1.4 Drive Mechanism—A drive mechanism for imparting
to the movable member a uniform, controlled velocity with
respect to the stationary member, with this velocity to be
regulated as specified in Section 8.
5.1.5 Load Indicator—A suitable load-indicating mechanism capable of showing the total tensile load carried by the
test specimen when held by the grips. This mechanism shall be
essentially free of inertia lag at the specified rate of testing and
shall indicate the load with an accuracy of 61 % of the
indicated value, or better. The accuracy of the testing machine
shall be verified in accordance with Practices E 4.
NOTE 8—Strain gages can be used as an alternative method to measure
axial and transverse strain; however, proper techniques for mounting
strain gages are crucial to obtaining accurate data. Consult strain gage
suppliers for instruction and training in these special techniques.
5.3 Micrometers—Suitable micrometers for measuring the
width and thickness of the test specimen to an incremental
discrimination of at least 0.025 mm (0.001 in.) should be used.
All width and thickness measurements of rigid and semirigid
plastics may be measured with a hand micrometer with ratchet.
A suitable instrument for measuring the thickness of nonrigid
test specimens shall have: (1) a contact measuring pressure of
25 6 2.5 kPa (3.6 6 0.36 psi), (2) a movable circular contact
foot 6.35 6 0.025 mm (0.250 6 0.001 in.) in diameter, and (3)
a lower fixed anvil large enough to extend beyond the contact
foot in all directions and being parallel to the contact foot
within 0.005 mm (0.0002 in.) over the entire foot area. Flatness
of the foot and anvil shall conform to Test Method D 5947.
5.3.1 An optional instrument equipped with a circular contact foot 15.88 6 0.08 mm (0.625 6 0.003 in.) in diameter is
recommended for thickness measuring of process samples or
larger specimens at least 15.88 mm in minimum width.
NOTE 7—Experience has shown that many testing machines now in use
are incapable of maintaining accuracy for as long as the periods between
inspection recommended in Practices E 4. Hence, it is recommended that
each machine be studied individually and verified as often as may be
found necessary. It frequently will be necessary to perform this function
daily.
5.1.6 The fixed member, movable member, drive mechanism, and grips shall be constructed of such materials and in
such proportions that the total elastic longitudinal strain of the
system constituted by these parts does not exceed 1 % of the
total longitudinal strain between the two gage marks on the test
specimen at any time during the test and at any load up to the
rated capacity of the machine.
5.2 Extension Indicator (extensometer)—A suitable instrument shall be used for determining the distance between two
designated points within the gage length of the test specimen as
the specimen is stretched. For referee purposes, the extensometer must be set at the full gage length of the specimen, as
shown in Fig. 1. It is desirable, but not essential, that this
instrument automatically record this distance, or any change in
it, as a function of the load on the test specimen or of the
elapsed time from the start of the test, or both. If only the latter
is obtained, load-time data must also be taken. This instrument
shall be essentially free of inertia at the specified speed of
testing. Extensometers shall be classified and their calibration
periodically verified in accordance with Practice E 83.
5.2.1 Modulus-of-Elasticity Measurements—For modulusof-elasticity measurements, an extensometer with a maximum
strain error of 0.0002 mm/mm (in./in.) that automatically and
continuously records shall be used. An extensometer classified
by Practice E 83 as fulfilling the requirements of a B-2
classification within the range of use for modulus measure-
6. Test Specimens
6.1 Sheet, Plate, and Molded Plastics:
6.1.1 Rigid and Semirigid Plastics—The test specimen shall
conform to the dimensions shown in Fig. 1. The Type I
specimen is the preferred specimen and shall be used where
sufficient material having a thickness of 7 mm (0.28 in.) or less
is available. The Type II specimen may be used when a
material does not break in the narrow section with the preferred
Type I specimen. The Type V specimen shall be used where
only limited material having a thickness of 4 mm (0.16 in.) or
less is available for evaluation, or where a large number of
specimens are to be exposed in a limited space (thermal and
environmental stability tests, etc.). The Type IV specimen
should be used when direct comparisons are required between
materials in different rigidity cases (that is, nonrigid and
semirigid). The Type III specimen must be used for all
materials with a thickness of greater than 7 mm (0.28 in.) but
not more than 14 mm (0.55 in.).
6.1.2 Nonrigid Plastics—The test specimen shall conform
to the dimensions shown in Fig. 1. The Type IV specimen shall
3
D 638
Specimen Dimensions for Thickness, T, mm (in.)A
7 (0.28) or under
Over 7 to 14 (0.28 to 0.55), incl
Dimensions (see drawings)
W—Width of narrow sectionE,F
L—Length of narrow section
WO—Width overall, minG
WO—Width overall, minG
LO—Length overall, minH
G—Gage lengthI
G—Gage lengthI
D—Distance between grips
R—Radius of fillet
RO—Outer radius (Type IV)
4 (0.16) or under
Type I
Type II
Type III
Type IVB
Type VC,D
13 (0.50)
57 (2.25)
19 (0.75)
...
165 (6.5)
50 (2.00)
...
115 (4.5)
76 (3.00)
...
6 (0.25)
57 (2.25)
19 (0.75)
...
183 (7.2)
50 (2.00)
...
135 (5.3)
76 (3.00)
...
19 (0.75)
57 (2.25)
29 (1.13)
...
246 (9.7)
50 (2.00)
...
115 (4.5)
76 (3.00)
...
6 (0.25)
33 (1.30)
19 (0.75)
...
115 (4.5)
...
25 (1.00)
65 (2.5)J
14 (0.56)
25 (1.00)
3.18 (0.125)
9.53 (0.375)
...
9.53 (0.375)
63.5 (2.5)
7.62 (0.300)
...
25.4 (1.0)
12.7 (0.5)
...
Tolerances
60.5 (60.02)B,C
60.5 (60.02)C
+ 6.4 ( + 0.25)
+ 3.18 ( + 0.125)
no max (no max)
60.25 (60.010)C
60.13 (60.005)
65 (60.2)
61 (60.04)C
61 (60.04)
A
Thickness, T, shall be 3.26 0.4 mm (0.13 6 0.02 in.) for all types of molded specimens, and for other Types I and II specimens where possible. If specimens are
machined from sheets or plates, thickness, T, may be the thickness of the sheet or plate provided this does not exceed the range stated for the intended specimen type.
For sheets of nominal thickness greater than 14 mm (0.55 in.) the specimens shall be machined to 14 6 0.4 mm (0.55 6 0.02 in.) in thickness, for use with the Type III
specimen. For sheets of nominal thickness between 14 and 51 mm (0.55 and 2 in.) approximately equal amounts shall be machined from each surface. For thicker sheets
both surfaces of the specimen shall be machined, and the location of the specimen with reference to the original thickness of the sheet shall be noted. Tolerances on
thickness less than 14 mm (0.55 in.) shall be those standard for the grade of material tested.
B
For the Type IV specimen, the internal width of the narrow section of the die shall be 6.00 6 0.05 mm (0.2506 0.002 in.). The dimensions are essentially those of Die
C in Test Methods D 412.
C
The Type V specimen shall be machined or die cut to the dimensions shown, or molded in a mold whose cavity has these dimensions. The dimensions shall be:
W = 3.18 6 0.03 mm (0.125 6 0.001 in.),
L = 9.53 6 0.08 mm (0.375 6 0.003 in.),
G = 7.62 6 0.02 mm (0.300 6 0.001 in.), and
R = 12.7 6 0.08 mm (0.500 6 0.003 in.).
The other tolerances are those in the table.
D
Supporting data on the introduction of the L specimen of Test Method D 1822 as the Type V specimen are available from ASTM Headquarters. Request RR:D20-1038.
E
The width at the center Wc shall be +0.00 mm, −0.10 mm ( +0.000 in., −0.004 in.) compared with width W at other parts of the reduced section. Any reduction in W
at the center shall be gradual, equally on each side so that no abrupt changes in dimension result.
F
For molded specimens, a draft of not over 0.13 mm (0.005 in.) may be allowed for either Type I or II specimens 3.2 mm (0.13 in.) in thickness, and this should be taken
into account when calculating width of the specimen. Thus a typical section of a molded Type I specimen, having the maximum allowable draft, could be as follows:
G
Overall widths greater than the minimum indicated may be desirable for some materials in order to avoid breaking in the grips.
H
Overall lengths greater than the minimum indicated may be desirable either to avoid breaking in the grips or to satisfy special test requirements.
I
Test marks or initial extensometer span.
J
When self-tightening grips are used, for highly extensible polymers, the distance between grips will depend upon the types of grips used and may not be critical if
maintained uniform once chosen.
FIG. 1 Tension Test Specimens for Sheet, Plate, and Molded Plastics
be used for testing nonrigid plastics with a thickness of 4 mm
(0.16 in.) or less. The Type III specimen must be used for all
materials with a thickness greater than 7 mm (0.28 in.) but not
more than 14 mm (0.55 in.).
6.1.3 Reinforced Composites—The test specimen for reinforced composites, including highly orthotropic laminates,
shall conform to the dimensions of the Type I specimen shown
in Fig. 1.
4
D 638
6.1.4 Preparation—Test specimens shall be prepared by
machining operations, or die cutting, from materials in sheet,
plate, slab, or similar form. Materials thicker than 14 mm (0.55
in.) must be machined to 14 mm (0.55 in.) for use as Type III
specimens. Specimens can also be prepared by molding the
material to be tested.
NOTE 9—Test results have shown that for some materials such as glass
cloth, SMC, and BMC laminates, other specimen types should be
considered to ensure breakage within the gage length of the specimen, as
mandated by 7.3.
NOTE 10—When preparing specimens from certain composite laminates such as woven roving, or glass cloth, care must be exercised in
cutting the specimens parallel to the reinforcement. The reinforcement
will be significantly weakened by cutting on a bias, resulting in lower
laminate properties, unless testing of specimens in a direction other than
parallel with the reinforcement constitutes a variable being studied.
NOTE 11—Specimens prepared by injection molding may have different
tensile properties than specimens prepared by machining or die-cutting
because of the orientation induced. This effect may be more pronounced
in specimens with narrow sections.
6.2 Rigid Tubes—The test specimen for rigid tubes shall be
as shown in Fig. 2. The length, L, shall be as shown in the table
in Fig. 2. A groove shall be machined around the outside of the
specimen at the center of its length so that the wall section after
machining shall be 60 % of the original nominal wall thickness. This groove shall consist of a straight section 57.2 mm
(2.25 in.) in length with a radius of 76 mm (3 in.) at each end
joining it to the outside diameter. Steel or brass plugs having
diameters such that they will fit snugly inside the tube and
having a length equal to the full jaw length plus 25 mm (1 in.)
shall be placed in the ends of the specimens to prevent
crushing. They can be located conveniently in the tube by
separating and supporting them on a threaded metal rod.
Details of plugs and test assembly are shown in Fig. 2.
6.3 Rigid Rods—The test specimen for rigid rods shall be as
shown in Fig. 3. The length, L, shall be as shown in the table
in Fig. 3. A groove shall be machined around the specimen at
the center of its length so that the diameter of the machined
portion shall be 60 % of the original nominal diameter. This
groove shall consist of a straight section 57.2 mm (2.25 in.) in
length with a radius of 76 mm (3 in.) at each end joining it to
the outside diameter.
6.4 All surfaces of the specimen shall be free of visible
flaws, scratches, or imperfections. Marks left by coarse machining operations shall be carefully removed with a fine file or
abrasive, and the filed surfaces shall then be smoothed with
abrasive paper (No. 00 or finer). The finishing sanding strokes
shall be made in a direction parallel to the long axis of the test
specimen. All flash shall be removed from a molded specimen,
taking great care not to disturb the molded surfaces. In
machining a specimen, undercuts that would exceed the
dimensional tolerances shown in Fig. 1 shall be scrupulously
avoided. Care shall also be taken to avoid other common
machining errors.
6.5 If it is necessary to place gage marks on the specimen,
this shall be done with a wax crayon or India ink that will not
affect the material being tested. Gage marks shall not be
scratched, punched, or impressed on the specimen.
6.6 When testing materials that are suspected of anisotropy,
DIMENSIONS OF ROD SPECIMENS
Nominal Diam- Length of Radial
eter
Sections, 2R.S.
Standard Length, L, of
Total Calculated
Specimen to Be Used
Minimum
for 89-mm (31⁄2-in.)
Length of Specimen
JawsA
mm (in.)
3.2 ( ⁄ )
4.7 (1⁄16)
6.4 (1⁄4)
9.5 (3⁄8)
12.7 (1⁄2)
15.9 (5⁄8)
19.0 (3⁄4)
22.2 (7⁄8)
25.4 (1)
31.8 (11⁄4)
38.1 (11⁄2)
42.5 (13⁄4)
50.8 (2)
18
19.6
24.0
27.7
33.9
39.0
43.5
47.6
51.5
54.7
60.9
66.4
71.4
76.0
(0.773)
(0.946)
(1.091)
(1.333)
(1.536)
(1.714)
(1.873)
(2.019)
(2.154)
(2.398)
(2.615)
(2.812)
(2.993)
356
361
364
370
376
380
384
388
391
398
403
408
412
(14.02)
(14.20)
(14.34)
(14.58)
(14.79)
(14.96)
(15.12)
(15.27)
(15.40)
(15.65)
(15.87)
(16.06)
(16.24)
381
381
381
381
400
400
400
400
419
419
419
419
432
(15)
(15)
(15)
(15)
(15.75)
(15.75)
(15.75)
(15.75)
(16.5)
(16.5)
(16.5)
(16.5)
(17)
A
For other jaws greater than 89 mm (3.5 in.), the standard length shall be
increased by twice the length of the jaws minus 178 mm (7 in.). The standard
length permits a slippage of approximately 6.4 to 12.7 mm (0.25 to 0.50 in.) in each
jaw while maintaining the maximum length of the jaw grip.
FIG. 3 Diagram Showing Location of Rod Tension Test Specimen
in Testing Machine
duplicate sets of test specimens shall be prepared, having their
long axes respectively parallel with, and normal to, the
suspected direction of anisotropy.
7. Number of Test Specimens
7.1 Test at least five specimens for each sample in the case
of isotropic materials.
5
D 638
a variable to be studied.
NOTE 12—Before testing, all transparent specimens should be inspected
in a polariscope. Those which show atypical or concentrated strain
patterns should be rejected, unless the effects of these residual strains
constitute a variable to be studied.
8. Speed of Testing
8.1 Speed of testing shall be the relative rate of motion of
the grips or test fixtures during the test. The rate of motion of
the driven grip or fixture when the testing machine is running
idle may be used, if it can be shown that the resulting speed of
testing is within the limits of variation allowed.
8.2 Choose the speed of testing from Table 1. Determine
this chosen speed of testing by the specification for the material
being tested, or by agreement between those concerned. When
the speed is not specified, use the lowest speed shown in Table
1 for the specimen geometry being used, which gives rupture
within 1⁄2 to 5-min testing time.
8.3 Modulus determinations may be made at the speed
selected for the other tensile properties when the recorder
response and resolution are adequate.
8.4 Poisson’s ratio determinations shall be made at the same
speed selected for modulus determinations.
9. Conditioning
9.1 Conditioning—Condition the test specimens at 23 6
2°C (73.4 6 3.6°F) and 50 6 5 % relative humidity for not less
than 40 h prior to test in accordance with Procedure A of
Practice D 618, unless otherwise specified by contract or the
relevant ASTM material specification. Reference pre-test conditioning, to settle disagreements, shall apply tolerances of
61°C (1.8°F) and 62 % relative humidity.
9.2 Test Conditions—Conduct the tests at 23 6 2°C (73.4 6
3.6°F) and 50 6 5 % relative humidity, unless otherwise
specified by contract or the relevant ASTM material specification. Reference testing conditions, to settle disagreements,
DIMENSIONS OF TUBE SPECIMENS
Nominal Wall
Thickness
Length of Radial
Total Calculated
Sections,
Minimum
2R.S.
Length of Specimen
Standard Length, L,
of Specimen to Be
Used for 89-mm
(3.5-in.) JawsA
mm (in.)
0.79 (1⁄32)
1.2 (3⁄64)
1.6 (1⁄16)
2.4 (3⁄32)
3.2 (1⁄8)
4.8 (3⁄16)
6.4 (1⁄4)
7.9 (5⁄16)
9.5 (3⁄8)
11.1 (7⁄16)
12.7 (1⁄2)
13.9
17.0
19.6
24.0
27.7
33.9
39.0
43.5
47.6
51.3
54.7
(0.547)
(0.670)
(0.773)
(0.946)
(1.091)
(1.333)
(1.536)
(1.714)
(1.873)
(2.019)
(2.154)
350
354
356
361
364
370
376
380
384
388
391
(13.80)
(13.92)
(14.02)
(14.20)
(14.34)
(14.58)
(14.79)
(14.96)
(15.12)
(15.27)
(15.40)
381
381
381
381
381
381
400
400
400
400
419
TABLE 1 Designations for Speed of TestingA
(15)
(15)
(15)
(15)
(15)
(15)
(15.75)
(15.75)
(15.75)
(15.75)
(16.5)
Classification
B
Rigid and Semirigid
Specimen Type
I, II, III rods and
tubes
IV
A
For other jaws greater than 89 mm (3.5 in.), the standard length shall be
increased by twice the length of the jaws minus 178 mm (7 in.). The standard
length permits a slippage of approximately 6.4 to 12.7 mm (0.25 to 0.50 in.) in each
jaw while maintaining the maximum length of the jaw grip.
V
Nonrigid
FIG. 2 Diagram Showing Location of Tube Tension Test
Specimens in Testing Machine
III
IV
7.2 Test ten specimens, five normal to, and five parallel
with, the principle axis of anisotropy, for each sample in the
case of anisotropic materials.
7.3 Discard specimens that break at some flaw, or that break
outside of the narrow cross-sectional test section (Fig. 1,
dimension “L”), and make retests, unless such flaws constitute
Speed of Testing,
mm/min (in./min)
5 (0.2) 6 25 %
50 (2) 6 10 %
500 (20) 6 10 %
5 (0.2) 6 25 %
50 (2) 6 10 %
500 (20) 6 10 %
1 (0.05) 6 25 %
10 (0.5) 6 25 %
100 (5)6 25 %
50 (2) 6 10 %
500 (20) 6 10 %
50 (2) 6 10 %
500 (20) 6 10 %
Nominal
StrainC Rate at
Start of Test,
mm/mm· min
(in./in.·min)
0.1
1
10
0.15
1.5
15
0.1
1
10
1
10
1.5
15
A
Select the lowest speed that produces rupture in 1⁄2 to 5 min for the specimen
geometry being used (see 8.2).
B
See Terminology D 883 for definitions.
C
The initial rate of straining cannot be calculated exactly for dumbbell-shaped
specimens because of extension, both in the reduced section outside the gage
length and in the fillets. This initial strain rate can be measured from the initial slope
of the tensile strain-versus-time diagram.
6
D 638
shall apply tolerances of 61°C (1.8°F) and 62 % relative
humidity.
TABLE 4 Elongation at Yield, %, for Eight Laboratories, Three
Materials
10. Procedure
10.1 Measure the width and thickness of rigid flat specimens (Fig. 1) with a suitable micrometer to the nearest 0.025
mm (0.001 in.) at several points along their narrow sections.
Measure the thickness of nonrigid specimens (produced by a
Type IV die) in the same manner with the required dial
micrometer. Take the width of this specimen as the distance
between the cutting edges of the die in the narrow section.
Measure the diameter of rod specimens, and the inside and
outside diameters of tube specimens, to the nearest 0.025 mm
(0.001 in.) at a minimum of two points 90° apart; make these
measurements along the groove for specimens so constructed.
Use plugs in testing tube specimens, as shown in Fig. 2.
Cellulose acetate butyrate
Acrylic
Polypropylene
Polypropylene
Acrylic
Glass-reinforced nylon
Glass-reinforced polyester
Sr
SR
Ir
IR
0.210
0.246
0.481
1.17
1.39
0.0089
0.0179
0.0179
0.0537
0.0894
0.071
0.035
0.063
0.217
0.266
0.025
0.051
0.051
0.152
0.253
0.201
0.144
0.144
0.614
0.753
10.3.1 Poisson’s Ratio Determination:
10.3.1.1 When Poisson’s ratio is determined, the speed of
testing and the load range at which it is determined shall be the
same as those used for modulus of elasticity.
10.3.1.2 Attach the transverse strain measuring device. The
transverse strain measuring device must continuously measure
the strain simultaneously with the axial strain measuring
device.
TABLE 3 Tensile Stress at Yield, 103 psi, for Eight Laboratories,
Three Materials
Sr
SR
Ir
IR
3.63
5.01
10.4
0.022
0.058
0.067
0.161
0.227
0.317
0.062
0.164
0.190
0.456
0.642
0.897
Ir
IR
0.62
0.55
5.86
0.76
0.59
1.27
1.75
1.56
16.5
11. Calculation
11.1 Toe compensation shall be made in accordance with
Annex A1, unless it can be shown that the toe region of the
curve is not due to the take-up of slack, seating of the
specimen, or other artifact, but rather is an authentic material
response.
11.2 Tensile Strength—Calculate the tensile strength by
dividing the maximum load in newtons (or pounds-force) by
the original minimum cross-sectional area of the specimen in
square metres (or square inches). Express the result in pascals
(or pounds-force per square inch) and report it to three
significant figures as tensile strength at yield or tensile strength
at break, whichever term is applicable. When a nominal yield
or break load less than the maximum is present and applicable,
it may be desirable also to calculate, in a similar manner, the
corresponding tensile stress at yield or tensile stress at break
and report it to three significant figures (see Note A2.8).
11.3 Percent Elongation—If the specimen gives a yield load
that is larger than the load at break, calculate percent elongation at yield. Otherwise, calculate percent elongation at break.
Do this by reading the extension (change in gage length) at the
moment the applicable load is reached. Divide that extension
by the original gage length and multiply by 100. Report percent
elongation at yield or percent elongation at break to two
significant figures. When a yield or breaking load less than the
maximum is present and of interest, it is desirable to calculate
and report both percent elongation at yield and percent
elongation at break (see Note A2.2).
11.4 Modulus of Elasticity—Calculate the modulus of elasticity by extending the initial linear portion of the loadextension curve and dividing the difference in stress corresponding to any segment of section on this straight line by the
corresponding difference in strain. All elastic modulus values
shall be computed using the average initial cross-sectional area
NOTE 13—Modulus of materials is determined from the slope of the
linear portion of the stress-strain curve. For most plastics, this linear
portion is very small, occurs very rapidly, and must be recorded automatically. The change in jaw separation is never to be used for calculating
modulus or elongation.
Mean
SR
0.27
0.21
0.45
NOTE 14—If it is desired to measure both modulus and failure properties (yield or break, or both), it may be necessary, in the case of highly
extensible materials, to run two independent tests. The high magnification
extensometer normally used to determine properties up to the yield point
may not be suitable for tests involving high extensibility. If allowed to
remain attached to the specimen, the extensometer could be permanently
damaged. A broad-range incremental extensometer or hand-rule technique
may be needed when such materials are taken to rupture.
10.2 Place the specimen in the grips of the testing machine,
taking care to align the long axis of the specimen and the grips
with an imaginary line joining the points of attachment of the
grips to the machine. The distance between the ends of the
gripping surfaces, when using flat specimens, shall be as
indicated in Fig. 1. On tube and rod specimens, the location for
the grips shall be as shown in Fig. 2 and Fig. 3. Tighten the
grips evenly and firmly to the degree necessary to prevent
slippage of the specimen during the test, but not to the point
where the specimen would be crushed.
10.3 Attach the extension indicator. When modulus is being
determined, a Class B-2 or better extensometer is required (see
5.2.1).
Polypropylene
Acrylic
Sr
3.65
4.89
8.79
10.3.1.3 Make simultaneous measurements of load and
strain and record the data. The precision of the value of
Poisson’s ratio will depend on the number of data points of
axial and transverse strain taken.
10.4 Set the speed of testing at the proper rate as required in
Section 8, and start the machine.
10.5 Record the load-extension curve of the specimen.
10.6 Record the load and extension at the yield point (if one
exists) and the load and extension at the moment of rupture.
TABLE 2 Modulus, 106 psi, for Eight Laboratories, Five Materials
Mean
Mean
7
D 638
FIG. 4 Plot of Strains Versus Load for Determination of Poisson’s Ratio
of the test specimens in the calculations. The result shall be
expressed in pascals (pounds-force per square inch) and
reported to three significant figures.
11.5 Secant Modulus—At a designated strain, this shall be
calculated by dividing the corresponding stress (nominal) by
the designated strain. Elastic modulus values are preferable and
shall be calculated whenever possible. However, for materials
where no proportionality is evident, the secant value shall be
calculated. Draw the tangent as directed in A1.3 and Fig. A1.2,
and mark off the designated strain from the yield point where
the tangent line goes through zero stress. The stress to be used
in the calculation is then determined by dividing the loadextension curve by the original average cross-sectional area of
the specimen.
11.6 Poisson’s Ratio—The axial strain, ea, indicated by the
axial extensometer, and the transverse strain, e, indicated by
the transverse extensometers, are plotted against the applied
load, P, as shown in Fig. 4. A straight line is drawn through
each set of points, and the slopes, dea / dP and det / dP, of these
lines are determined. Poisson’s ratio, µ, is then calculated as
follows:
µ 5 2~det / dP!/~dea / dP!
where:
s = estimated standard deviation,
X = value of single observation,
n = number of observations, and
X̄ = arithmetic mean of the set of observations.
11.9 See Annex A1 for information on toe compensation.
TABLE 5 Tensile Strength at Break, 103 psi, for Eight
Laboratories, Five MaterialsA
Polypropylene
Acrylic
SR
Ir
IR
1.54
0.058
0.452
0.233
0.277
1.65
0.180
0.751
0.437
0.698
4.37
0.164
1.27
0.659
0.784
4.66
0.509
2.13
1.24
1.98
TABLE 6 Elongation at Break, %, for Eight Laboratories, Five
MaterialsA
(1)
Acrylic
Polypropylene
Mean
Sr
SR
Ir
IR
3.68
3.87
13.2
14.1
293.0
0.20
0.10
2.05
1.87
50.9
2.33
2.13
3.65
6.62
119.0
0.570
0.283
5.80
5.29
144.0
6.59
6.03
10.3
18.7
337.0
A
Tensile strength and elongation at break values obtained for unreinforced
propylene plastics generally are highly variable due to inconsistencies in necking
or “drawing” of the center section of the test bar. Since tensile strength and
elongation at yield are more reproducible and relate in most cases to the practical
usefulness of a molded part, they are generally recommended for specification
purposes.
(2)
11.6.1 The errors that may be introduced by drawing a
straight line through the points can be reduced by applying the
method of least squares.
11.7 For each series of tests, calculate the arithmetic mean
of all values obtained and report it as the “average value” for
the particular property in question.
11.8 Calculate the standard deviation (estimated) as follows
and report it to two significant figures:
s 5 =~ (X 2 2 nX̄ 2! / ~n 2 1!
Sr
2.97
4.82
9.09
20.8
23.6
A
Tensile strength and elongation at break values obtained for unreinforced
propylene plastics generally are highly variable due to inconsistencies in necking
or “drawing” of the center section of the test bar. Since tensile strength and
elongation at yield are more reproducible and relate in most cases to the practical
usefulness of a molded part, they are generally recommended for specification
purposes.
where:
det = change in transverse strain,
dea = change in axial strain, and
dP = change in applied load;
or
µ 5 2~det! / ~dea!
Mean
12. Report
12.1 Report the following information:
12.1.1 Complete identification of the material tested, including type, source, manufacturer’s code numbers, form, principal
dimensions, previous history, etc.,
12.1.2 Method of preparing test specimens,
12.1.3 Type of test specimen and dimensions,
(3)
8
D 638
TABLE 7 Tensile Yield Strength, for Ten Laboratories, Eight
Materials
Material
LDPE
LDPE
LLDPE
LLDPE
LLDPE
LLDPE
HDPE
HDPE
Test
Speed,
in./min
Average
Sr
SR
r
R
20
20
20
20
20
20
2
2
1544
1894
1879
1791
2900
1730
4101
3523
52.4
53.1
74.2
49.2
55.5
63.9
196.1
175.9
64.0
61.2
99.9
75.8
87.9
96.0
371.9
478.0
146.6
148.7
207.8
137.9
155.4
178.9
549.1
492.4
179.3
171.3
279.7
212.3
246.1
268.7
1041.3
1338.5
TABLE 9 Tensile Break Strength, for Nine Laboratories, Six
Materials
Values Expressed in psi Units
Material
LDPE
LDPE
LLDPE
LLDPE
LLDPE
LLDPE
Test
Speed,
in./min
Average
Sr
SR
r
R
20
20
20
20
20
20
1592
1750
4379
2840
1679
2660
52.3
66.6
127.1
78.6
34.3
119.1
74.9
102.9
219.0
143.5
47.0
166.3
146.4
186.4
355.8
220.2
95.96
333.6
209.7
288.1
613.3
401.8
131.6
465.6
Values Expressed in psi Units
TABLE 10 Tensile Break Elongation, for Nine Laboratories, Six
Materials
12.1.4 Conditioning procedure used,
12.1.5 Atmospheric conditions in test room,
12.1.6 Number of specimens tested,
12.1.7 Speed of testing,
12.1.8 Classification of extensometers used. A description
of measuring technique and calculations employed instead of a
minimum Class-C extensometer system,
12.1.9 Tensile strength at yield or break, average value, and
standard deviation,
12.1.10 Tensile stress at yield or break, if applicable,
average value, and standard deviation,
12.1.11 Percent elongation at yield or break, or both, as
applicable, average value, and standard deviation,
12.1.12 Modulus of elasticity, average value, and standard
deviation,
12.1.13 Date of test, and
12.1.14 Revision date of Test Method D 638.
Material
LDPE
LDPE
LLDPE
LLDPE
LLDPE
LLDPE
TABLE 8 Tensile Yield Elongation, for Eight Laboratories, Eight
Materials
LDPE
LDPE
LLDPE
LLDPE
LLDPE
LLDPE
HDPE
HDPE
Test
Speed,
in./min
Average
Sr
SR
r
R
20
20
20
20
20
20
2
2
17.0
14.6
15.7
16.6
11.7
15.2
9.27
9.63
1.26
1.02
1.37
1.59
1.27
1.27
1.40
1.23
3.16
2.38
2.85
3.30
2.88
2.59
2.84
2.75
3.52
2.86
3.85
4.46
3.56
3.55
3.91
3.45
8.84
6.67
7.97
9.24
8.08
7.25
7.94
7.71
Average
Sr
SR
r
R
20
20
20
20
20
20
567
569
890
64.4
803
782
31.5
61.5
25.7
6.68
25.7
41.6
59.5
89.2
113.8
11.7
104.4
96.7
88.2
172.3
71.9
18.7
71.9
116.6
166.6
249.7
318.7
32.6
292.5
270.8
Values Expressed in Percent Units
individual specimens were prepared at the laboratories that
tested them. Each test result was the average of five individual
determinations. Each laboratory obtained three test results for
each material. Data from some laboratories could not be used
for various reasons, and this is noted in each table.
13.1.2 In Tables 2-10, for the materials indicated, and for
test results that derived from testing five specimens:
13.1.2.1 Sr is the within-laboratory standard deviation of
the average; Ir = 2.83 Sr. (See 13.1.2.3 for application of Ir.)
13.1.2.2 SR is the between-laboratory standard deviation of
the average; IR = 2.83 SR. (See 13.1.2.4 for application of IR.)
13.1.2.3 Repeatability—In comparing two test results for
the same material, obtained by the same operator using the
same equipment on the same day, those test results should be
judged not equivalent if they differ by more than the Ir value
for that material and condition.
13.1.2.4 Reproducibility—In comparing two test results for
the same material, obtained by different operators using different equipment on different days, those test results should be
judged not equivalent if they differ by more than the IR value
for that material and condition. (This applies between different
laboratories or between different equipment within the same
laboratory.)
13.1.2.5 Any judgment in accordance with 13.1.2.3 and
13.1.2.4 will have an approximate 95 % (0.95) probability of
being correct.
13.1.2.6 Other formulations may give somewhat different
results.
13.1.2.7 For further information on the methodology used in
this section, see Practice E 691.
13.1.2.8 The precision of this test method is very dependent
upon the uniformity of specimen preparation, standard practices for which are covered in other documents.
13.2 Bias—There are no recognized standards on which to
base an estimate of bias for this test method.
13. Precision and Bias 12
13.1 Precision—Tables 2-6 are based on a round-robin test
conducted in 1984, involving five materials tested by eight
laboratories using the Type I specimen, all of nominal 0.125-in.
thickness. Each test result was based on five individual
determinations. Each laboratory obtained two test results for
each material.
Material
Test
Speed,
in./min
Values Expressed in Percent Units
13.1.1 Tables 7-10 are based on a round-robin test conducted by the polyolefin subcommittee in 1988, involving eight
polyethylene materials tested in ten laboratories. For each
material, all samples were molded at one source, but the
12
Supporting data are available from ASTM Headquarters. Request RR:D201125 for the 1984 round robin and RR:D20-1170 for the 1988 round robin.
9
D 638
14. Keywords
14.1 modulus of elasticity; percent elongation; plastics;
tensile properties; tensile strength
ANNEXES
(Mandatory Information)
A1. TOE COMPENSATION
A1.1 In a typical stress-strain curve (Fig. A1.1) there is a
toe region, AC, that does not represent a property of the
material. It is an artifact caused by a takeup of slack and
alignment or seating of the specimen. In order to obtain correct
values of such parameters as modulus, strain, and offset yield
point, this artifact must be compensated for to give the
corrected zero point on the strain or extension axis.
elastic modulus can be determined by dividing the stress at any
point along the line CD (or its extension) by the strain at the
same point (measured from Point B, defined as zero-strain).
A1.3 In the case of a material that does not exhibit any
linear region (Fig. A1.2), the same kind of toe correction of the
zero-strain point can be made by constructing a tangent to the
maximum slope at the inflection point (H8). This is extended to
intersect the strain axis at Point B8, the corrected zero-strain
point. Using Point B8 as zero strain, the stress at any point (G8)
on the curve can be divided by the strain at that point to obtain
a secant modulus (slope of Line B8 G8). For those materials
with no linear region, any attempt to use the tangent through
the inflection point as a basis for determination of an offset
yield point may result in unacceptable error.
A1.2 In the case of a material exhibiting a region of
Hookean (linear) behavior (Fig. A1.1), a continuation of the
linear (CD) region of the curve is constructed through the
zero-stress axis. This intersection (B) is the corrected zerostrain point from which all extensions or strains must be
measured, including the yield offset (BE), if applicable. The
NOTE 1—Some chart recorders plot the mirror image of this graph.
NOTE 1—Some chart recorders plot the mirror image of this graph.
FIG. A1.1 Material with Hookean Region
FIG. A1.2 Material with No Hookean Region
10
D 638
A2. DEFINITIONS OF TERMS AND SYMBOLS RELATING TO TENSION TESTING OF PLASTICS
A2.1 elastic limit—the greatest stress which a material is
capable of sustaining without any permanent strain remaining
upon complete release of the stress. It is expressed in force per
unit area, usually pounds-force per square inch (megapascals).
NOTE A2.1—Measured values of proportional limit and elastic limit
vary greatly with the sensitivity and accuracy of the testing equipment,
eccentricity of loading, the scale to which the stress-strain diagram is
plotted, and other factors. Consequently, these values are usually replaced
by yield strength.
A2.2 elongation—the increase in length produced in the
gage length of the test specimen by a tensile load. It is
expressed in units of length, usually inches (millimetres). (Also
known as extension.)
NOTE A2.2—Elongation and strain values are valid only in cases where
uniformity of specimen behavior within the gage length is present. In the
case of materials exhibiting necking phenomena, such values are only of
qualitative utility after attainment of yield point. This is due to inability to
ensure that necking will encompass the entire length between the gage
marks prior to specimen failure.
FIG. A2.1 Offset Yield Strength
The stress at the point of intersection r is the “offset yield strength.” The
specified value of the offset must be stated as a percent of the original gage
length in conjunction with the strength value. Example: 0.1 % offset yield
strength = ... MPa (psi), or yield strength at 0.1 % offset ... MPa (psi).
A2.3 gage length—the original length of that portion of the
specimen over which strain or change in length is determined.
A2.7 percent elongation—the elongation of a test specimen
expressed as a percent of the gage length.
A2.4 modulus of elasticity—the ratio of stress (nominal) to
corresponding strain below the proportional limit of a material.
It is expressed in force per unit area, usually megapascals
(pounds-force per square inch). (Also known as elastic modulus or Young’s modulus).
A2.8 percent elongation at break and yield:
A2.8.1 percent elongation at break
the percent elongation at the moment of rupture of the test
specimen.
A2.8.2 percent elongation at yield
the percent elongation at the moment the yield point (A2.21)
is attained in the test specimen.
NOTE A2.3—The stress-strain relations of many plastics do not conform to Hooke’s law throughout the elastic range but deviate therefrom
even at stresses well below the elastic limit. For such materials the slope
of the tangent to the stress-strain curve at a low stress is usually taken as
the modulus of elasticity. Since the existence of a true proportional limit
in plastics is debatable, the propriety of applying the term “modulus of
elasticity” to describe the stiffness or rigidity of a plastic has been
seriously questioned. The exact stress-strain characteristics of plastic
materials are very dependent on such factors as rate of stressing,
temperature, previous specimen history, etc. However, such a value is
useful if its arbitrary nature and dependence on time, temperature, and
other factors are realized.
A2.9 percent reduction of area (nominal)—the difference
between the original cross-sectional area measured at the point
of rupture after breaking and after all retraction has ceased,
expressed as a percent of the original area.
A2.5 necking—the localized reduction in cross section
which may occur in a material under tensile stress.
A2.10 percent reduction of area (true)—the difference
between the original cross-sectional area of the test specimen
and the minimum cross-sectional area within the gage boundaries prevailing at the moment of rupture, expressed as a
percentage of the original area.
A2.6 offset yield strength—the stress at which the strain
exceeds by a specified amount (the offset) an extension of the
initial proportional portion of the stress-strain curve. It is
expressed in force per unit area, usually megapascals (poundsforce per square inch).
A2.11 proportional limit—the greatest stress which a
material is capable of sustaining without any deviation from
proportionality of stress to strain (Hooke’s law). It is expressed
in force per unit area, usually megapascals (pounds-force per
square inch).
NOTE A2.4—This measurement is useful for materials whose stressstrain curve in the yield range is of gradual curvature. The offset yield
strength can be derived from a stress-strain curve as follows (Fig. A2.1):
A2.12 rate of loading—the change in tensile load carried
by the specimen per unit time. It is expressed in force per unit
time, usually newtons (pounds-force) per minute. The initial
rate of loading can be calculated from the initial slope of the
load versus time diagram.
On the strain axis lay off OM equal to the specified offset.
Draw OA tangent to the initial straight-line portion of the stress-strain
curve.
Through M draw a line MN parallel to OA and locate the intersection of
MN with the stress-strain curve.
A2.13 rate of straining—the change in tensile strain per
unit time. It is expressed either as strain per unit time, usually
11
D 638
metres per metre (inches per inch) per minute, or percent
elongation per unit time, usually percent elongation per minute.
The initial rate of straining can be calculated from the initial
slope of the tensile strain versus time diagram.
NOTE A2.5—The initial rate of straining is synonymous with the rate of
crosshead movement divided by the initial distance between crossheads
only in a machine with constant rate of crosshead movement and when the
specimen has a uniform original cross section, does not “neck down,” and
does not slip in the jaws.
FIG. A2.2 Illustration of True Strain Equation
eT 5
A2.14 rate of stressing (nominal)—the change in tensile
stress (nominal) per unit time. It is expressed in force per unit
area per unit time, usually megapascals (pounds-force per
square inch) per minute. The initial rate of stressing can be
calculated from the initial slope of the tensile stress (nominal)
versus time diagram.
* dL/L 5 ln L/L
L
Lo
o
(A2.1)
where:
dL = increment of elongation when the distance between
the gage marks is L,
Lo = original distance between gage marks, and
L
= distance between gage marks at any time.
A2.21 yield point—the first point on the stress-strain curve
at which an increase in strain occurs without an increase in
stress (Fig. A2.2).
NOTE A2.6—The initial rate of stressing as determined in this manner
has only limited physical significance. It does, however, roughly describe
the average rate at which the initial stress (nominal) carried by the test
specimen is applied. It is affected by the elasticity and flow characteristics
of the materials being tested. At the yield point, the rate of stressing (true)
may continue to have a positive value if the cross-sectional area is
decreasing.
NOTE A2.9—Only materials whose stress-strain curves exhibit a point
of zero slope may be considered as having a yield point.
NOTE A2.10—Some materials exhibit a distinct “break” or discontinuity in the stress-strain curve in the elastic region. This break is not a yield
point by definition. However, this point may prove useful for material
characterization in some cases.
A2.15 secant modulus—the ratio of stress (nominal) to
corresponding strain at any specified point on the stress-strain
curve. It is expressed in force per unit area, usually megapascals (pounds-force per square inch), and reported together with
the specified stress or strain.
A2.22 yield strength—the stress at which a material exhibits a specified limiting deviation from the proportionality of
stress to strain. Unless otherwise specified, this stress will be
the stress at the yield point and when expressed in relation to
the tensile strength shall be designated either tensile strength at
yield or tensile stress at yield as required in A2.17 (Fig. A2.3).
(See offset yield strength.)
NOTE A2.7—This measurement is usually employed in place of modulus of elasticity in the case of materials whose stress-strain diagram does
not demonstrate proportionality of stress to strain.
A2.16 strain—the ratio of the elongation to the gage length
of the test specimen, that is, the change in length per unit of
original length. It is expressed as a dimensionless ratio.
A2.17 tensile strength (nominal)—the maximum tensile
stress (nominal) sustained by the specimen during a tension
test. When the maximum stress occurs at the yield point
(A2.21), it shall be designated tensile strength at yield. When
the maximum stress occurs at break, it shall be designated
tensile strength at break.
A2.23 Symbols—The following symbols may be used for
the above terms:
Symbol
W
DW
L
Lo
Lu
DL
A
Ao
DA
Au
A2.18 tensile stress (nominal)—the tensile load per unit
area of minimum original cross section, within the gage
boundaries, carried by the test specimen at any given moment.
It is expressed in force per unit area, usually megapascals
(pounds-force per square inch).
AT
t
Dt
s
Ds
sT
sU
sUT
e
De
eU
eT
%El
Y.P.
E
NOTE A2.8—The expression of tensile properties in terms of the
minimum original cross section is almost universally used in practice. In
the case of materials exhibiting high extensibility or necking, or both
(A2.15), nominal stress calculations may not be meaningful beyond the
yield point (A2.21) due to the extensive reduction in cross-sectional area
that ensues. Under some circumstances it may be desirable to express the
tensile properties per unit of minimum prevailing cross section. These
properties are called true tensile properties (that is, true tensile stress, etc.).
A2.19 tensile stress-strain curve—a diagram in which
values of tensile stress are plotted as ordinates against corresponding values of tensile strain as abscissas.
Term
Load
Increment of load
Distance between gage marks at any time
Original distance between gage marks
Distance between gage marks at moment of rupture
Increment of distance between gage marks = elongation
Minimum cross-sectional area at any time
Original cross-sectional area
Increment of cross-sectional area
Cross-sectional area at point of rupture measured after
breaking specimen
Cross-sectional area at point of rupture, measured at the
moment of rupture
Time
Increment of time
Tensile stress
Increment of stress
True tensile stress
Tensile strength at break (nominal)
Tensile strength at break (true)
Strain
Increment of strain
Total strain, at break
True strain
Percentage elongation
Yield point
Modulus of elasticity
A2.24
Relations between these various terms may be
defined as follows:
A2.20 true strain (see Fig. A2.2) is defined by the following equation for eT:
12
D 638
sU
sUT
e
eU
eT
%El
=
=
=
=
=
=
W/Ao (where W is breaking load)
W/AT (where W is breaking load)
DL/Lo = (L − Lo)/Lo
(Lu − Lo)/Lo
*LLo dL/L 5 ln L/Lo
[(L − Lo)/Lo] 3 100 = e 3 100
Percent reduction of area (nominal) = [(Ao − Au)/Ao] 3 100
Percent reduction of area (true) = [(Ao − AT)/Ao] 3 100
Rate of loading = DW/Dt
Rate of stressing (nominal) = Ds/D = (DW]/Ao)/Dt
Rate of straining = De/Dt = (DL/Lo)Dt
For the case where the volume of the test specimen does not
change during the test, the following three relations hold:
sT 5 s~1 1 e! 5 sL/Lo
(A2.2)
sUT 5 sU ~1 1 eU! 5 sU Lu /Lo
A 5 Ao /~1 1 e!
FIG. A2.3 Tensile Designations
s
sT
=
=
W/Ao
W/A
SUMMARY OF CHANGES
This section identifies the location of selected changes to this test method. For the convenience of the user,
Committee D20 has highlighted those changes that may impact the use of this test method. This section may also
include descriptions of the changes or reasons for the changes, or both.
D 638–02:
(1) Revised 9.1 and 9.2.
D 638–01:
(1) Modified 7.3 regarding conditions for specimen discard.
D 638–00:
(1) Added 11.1 and renumbered subsequent sections.
D 638–99:
(1) Added and clarified extensometer classification requirements.
D 638–98:
(1) Revised 10.3 and added 12.1.8 to clarify extensometer
usage.
(2) Added 12.1.14.
(3) Replaced reference to Test Methods D 374 with Test
Method D 5947 in 2.1 and 5.3.
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13
D 638
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14
Standard Test Methods for
Flexural Properties of Unreinforced and Reinforced Plastics
and Electrical Insulating Materials1
This standard has been approved for use by agencies of the Department of Defense.
1. Scope *
1.1 These test methods cover the determination of flexural
properties of unreinforced and reinforced plastics, including
high-modulus composites and electrical insulating materials in
the form of rectangular bars molded directly or cut from sheets,
plates, or molded shapes. These test methods are generally
applicable to both rigid and semirigid materials. However,
flexural strength cannot be determined for those materials that
do not break or that do not fail in the outer surface of the test
specimen within the 5.0 % strain limit of these test methods.
These test methods utilize a three-point loading system applied
to a simply supported beam. A four-point loading system
method can be found in Test Method D 6272.
1.1.1 Procedure A, designed principally for materials that
break at comparatively small deflections.
1.1.2 Procedure B, designed particularly for those materials
that undergo large deflections during testing.
1.1.3 Procedure A shall be used for measurement of flexural
properties, particularly flexural modulus, unless the material
specification states otherwise. Procedure B may be used for
measurement of flexural strength only. Tangent modulus data
obtained by Procedure A tends to exhibit lower standard
deviations than comparable data obtained by means of Procedure B.
1.2 Comparative tests may be run in accordance with either
procedure, provided that the procedure is found satisfactory for
the material being tested.
standard. The values provided in parentheses are for information only.
2.1 ASTM Standards:
D 638 Test Method for Tensile Properties of Plastics2
D 5947 Test Methods for Physical Dimensions of Solid
Plastic Specimens4
D 6272 Test Method for Flexural Properties of Unreinforced and Reinforced Plastics and Electrical Insulating
Materials by Four-Point Bending4
E 4 Practices for Force Verification of Testing Machines5
E 691 Practice for Conducting an Interlaboratory Study to
Determine the Precision of a Test Method6
3. Terminology
3.1 Definitions—Definitions of terms applying to these test
methods appear in Terminology D 883 and Annex A1 of Test
Method D 638.
4. Summary of Test Method
4.1 A bar of rectangular cross section rests on two supports
and is loaded by means of a loading nose midway between the
supports (see Fig. 1). A support span-to-depth ratio of 16:1
shall be used unless there is reason to suspect that a larger
span-to-depth ratio may be required, as may be the case for
certain laminated materials (see Section 7 and Note 8 for
guidance).
4.2 The specimen is deflected until rupture occurs in the
outer surface of the test specimen or until a maximum strain
(see 12.7) of 5.0 % is reached, whichever occurs first.
4.3 Procedure A employs a strain rate of 0.01 mm/mm/min
(0.01 in./in./min) and is the preferred procedure for this test
method, while Procedure B employs a strain rate of 0.10
mm/mm/min (0.10 in./in./min).
NOTE 1—These test methods are not technically equivalent to ISO 178.
2
1
These test methods are under the jurisdiction of ASTM Committee D20 on
Plastics and are the direct responsibility of Subcommittee D20.10 on Mechanical
Properties.
Current edition approved April 10, 2002. Published June 2002. Originally
published as D 790 – 70. Last previous edition D 790 – 00.
Annual
Annual
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Book
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of
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ASTM
ASTM
ASTM
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Standards,
Standards,
Standards,
Standards,
Standards,
1
Vol
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08.01.
08.02.
08.03.
03.01.
14.02.
D 790
TABLE 1 Flexural Strength
Material
ABS
DAP thermoset
Cast acrylic
GR polyester
GR polycarbonate
SMC
Mean, 103 psi
9.99
14.3
16.3
19.5
21.0
26.0
Values Expressed in Units of %
of 103 psi
VrA
VRB
rC
RD
1.59
6.58
1.67
1.43
5.16
4.76
6.05
6.58
11.3
2.14
6.05
7.19
4.44
18.6
4.73
4.05
14.6
13.5
17.2
18.6
32.0
6.08
17.1
20.4
A
Vr = within-laboratory coefficient of variation for the indicated material. It is
obtained by first pooling the within-laboratory standard deviations of the test
results from all of the participating laboratories: Sr = [[(s1)2 + (s2)2 . . . + ( sn)2]/n]
1/2 then Vr = (Sr divided by the overall average for the material) 3 100.
B
Vr = between-laboratory reproducibility, expressed as the coefficient of variation: SR = {Sr2 + SL2}1/2 where SL is the standard deviation of laboratory means.
Then: VR = (S R divided by the overall average for the material) 3 100.
C
r = within-laboratory critical interval between two test results = 2.8 3 Vr.
D
R = between-laboratory critical interval between two test results = 2.8 3 VR.
testing, or appropriate corrections shall be made. The load
indicating mechanism shall be essentially free from inertial lag
at the crosshead rate used. The accuracy of the testing machine
shall be verified in accordance with Practices E 4.
6.2 Loading Noses and Supports—The loading nose and
supports shall have cylindrical surfaces. In order to avoid
excessive indentation, or failure due to stress concentration
directly under the loading nose, the radii of the loading nose
and supports shall be 5.0 6 0.1 mm (0.197 6 0.004 in.) unless
otherwise specified or agreed upon between the interested
clients. When other loading noses and supports are used they
must comply with the following requirements: they shall have
a minimum radius of 3.2 mm (1⁄8 in.) for all specimens, and for
specimens 3.2 mm or greater in depth, the radius of the
supports may be up to 1.6 times the specimen depth. They shall
be this large if significant indentation or compressive failure
occurs. The arc of the loading nose in contact with the
specimen shall be sufficiently large to prevent contact of the
specimen with the sides of the nose (see Fig. 1). The maximum
radius of the loading nose shall be no more than 4 times the
specimen depth.
NOTE—(a) Minimum radius = 3.2 mm (1⁄8 in.). (b) Maximum radius
supports 1.6 times specimen depth; maximum radius loading nose = 4
times specimen depth.
FIG. 1
Allowable Range of Loading Nose and Support Radii
5.1 Flexural properties as determined by these test methods
are especially useful for quality control and specification
purposes.
5.2 Materials that do not fail by the maximum strain
allowed under these test methods (3-point bend) may be more
suited to a 4-point bend test. The basic difference between the
two test methods is in the location of the maximum bending
moment and maximum axial fiber stresses. The maximum axial
fiber stresses occur on a line under the loading nose in 3-point
bending and over the area between the loading noses in 4-point
bending.
5.3 Flexural properties may vary with specimen depth,
temperature, atmospheric conditions, and the difference in rate
of straining as specified in Procedures A and B (see also Note
8).
5.4 Before proceeding with these test methods, reference
should be made to the specification of the material being tested.
Any test specimen preparation, conditioning, dimensions, or
testing parameters, or combination thereof, covered in the
materials specification shall take precedence over those mentioned in these test methods. If there are no material specifications, then the default conditions apply. Table 1 in Classification System D 4000 lists the ASTM materials standards that
currently exist for plastics.
NOTE 2—Test data have shown that the loading nose and support
dimensions can influence the flexural modulus and flexural strength
values. The loading nose dimension has the greater influence. Dimensions
of the loading nose and supports must be specified in the material
specification.
6.3 Micrometers— Suitable micrometers for measuring the
width and thickness of the test specimen to an incremental
discrimination of at least 0.025 mm (0.001 in.) should be used.
All width and thickness measurements of rigid and semirigid
plastics may be measured with a hand micrometer with ratchet.
A suitable instrument for measuring the thickness of nonrigid
test specimens shall have: a contact measuring pressure of
25 6 2.5 kPa (3.6 6 0.36 psi), a movable circular contact foot
6.35 6 0.025 mm (0.250 6 0.001 in.) in diameter and a lower
fixed anvil large enough to extend beyond the contact foot in
all directions and being parallel to the contact foot within 0.005
mm (0.002 in.) over the entire foot area. Flatness of foot and
anvil shall conform to the portion of the Calibration section of
Test Methods D 5947.
6. Apparatus
6.1 Testing Machine— A properly calibrated testing machine that can be operated at constant rates of crosshead motion
over the range indicated, and in which the error in the load
measuring system shall not exceed 61 % of the maximum load
expected to be measured. It shall be equipped with a deflection
measuring device. The stiffness of the testing machine shall be
such that the total elastic deformation of the system does not
exceed 1 % of the total deflection of the test specimen during
7. Test Specimens
7.1 The specimens may be cut from sheets, plates, or
2
D 790
be necessary (32:1 or 40:1 are recommended). When laminated
materials exhibit low compressive strength perpendicular to the
laminations, they shall be loaded with a large radius loading
nose (up to four times the specimen depth to prevent premature
damage to the outer fibers.
7.4 Molding Materials (Thermoplastics and Thermosets)—
The recommended specimen for molding materials is 127 by
12.7 by 3.2 mm (5 by 1⁄2by 1⁄8 in.) tested flatwise on a support
span, resulting in a support span-to-depth ratio of 16 (tolerance
61). Thicker specimens should be avoided if they exhibit
significant shrink marks or bubbles when molded.
7.5 High-Strength Reinforced Composites, Including Highly
Orthotropic Laminates—The span-to-depth ratio shall be chosen such that failure occurs in the outer fibers of the specimens
and is due only to the bending moment (see Note 8). A
span-to-depth ratio larger than 16:1 may be necessary (32:1 or
40:1 are recommended). For some highly anisotropic composites, shear deformation can significantly influence modulus
measurements, even at span-to-depth ratios as high as 40:1.
Hence, for these materials, an increase in the span-to-depth
ratio to 60:1 is recommended to eliminate shear effects when
modulus data are required, it should also be noted that the
flexural modulus of highly anisotropic laminates is a strong
function of ply-stacking sequence and will not necessarily
correlate with tensile modulus, which is not stacking-sequence
dependent.
molded shapes, or may be molded to the desired finished
dimensions. The actual dimensions used in Section 4.2, Calculation, shall be measured in accordance with Test Methods
D 5947.
NOTE 3—Any necessary polishing of specimens shall be done only in
the lengthwise direction of the specimen.
7.2 Sheet Materials (Except Laminated Thermosetting Materials and Certain Materials Used for Electrical Insulation,
Including Vulcanized Fiber and Glass Bonded Mica):
7.2.1 Materials 1.6 mm (1⁄16 in.) or Greater in Thickness—
For flatwise tests, the depth of the specimen shall be the
thickness of the material. For edgewise tests, the width of the
specimen shall be the thickness of the sheet, and the depth shall
not exceed the width (see Notes 4 and 5). For all tests, the
support span shall be 16 (tolerance 61) times the depth of the
beam. Specimen width shall not exceed one fourth of the
support span for specimens greater than 3.2 mm (1⁄8 in.) in
depth. Specimens 3.2 mm or less in depth shall be 12.7 mm (1⁄2
in.) in width. The specimen shall be long enough to allow for
overhanging on each end of at least 10 % of the support span,
but in no case less than 6.4 mm (1⁄4 in.) on each end. Overhang
shall be sufficient to prevent the specimen from slipping
through the supports.
NOTE 4—Whenever possible, the original surface of the sheet shall be
unaltered. However, where testing machine limitations make it impossible
to follow the above criterion on the unaltered sheet, one or both surfaces
shall be machined to provide the desired dimensions, and the location of
the specimens with reference to the total depth shall be noted. The value
obtained on specimens with machined surfaces may differ from those
obtained on specimens with original surfaces. Consequently, any specifications for flexural properties on thicker sheets must state whether the
original surfaces are to be retained or not. When only one surface was
machined, it must be stated whether the machined surface was on the
tension or compression side of the beam.
NOTE 5—Edgewise tests are not applicable for sheets that are so thin
that specimens meeting these requirements cannot be cut. If specimen
depth exceeds the width, buckling may occur.
NOTE 8—As a general rule, support span-to-depth ratios of 16:1 are
satisfactory when the ratio of the tensile strength to shear strength is less
than 8 to 1, but the support span-to-depth ratio must be increased for
composite laminates having relatively low shear strength in the plane of
the laminate and relatively high tensile strength parallel to the support
span.
8. Number of Test Specimens
8.1 Test at least five specimens for each sample in the case
of isotropic materials or molded specimens.
8.2 For each sample of anisotropic material in sheet form,
test at least five specimens for each of the following conditions.
Recommended conditions are flatwise and edgewise tests on
specimens cut in lengthwise and crosswise directions of the
sheet. For the purposes of this test, “lengthwise” designates the
principal axis of anisotropy and shall be interpreted to mean the
direction of the sheet known to be stronger in flexure. “Crosswise” indicates the sheet direction known to be the weaker in
flexure and shall be at 90° to the lengthwise direction.
7.2.2 Materials Less than 1.6 mm (1⁄16 in.) in Thickness—
The specimen shall be 50.8 mm (2 in.) long by 12.7 mm (1⁄2 in.)
wide, tested flatwise on a 25.4-mm (1-in.) support span.
NOTE 6—Use of the formulas for simple beams cited in these test
methods for calculating results presumes that beam width is small in
comparison with the support span. Therefore, the formulas do not apply
rigorously to these dimensions.
NOTE 7—Where machine sensitivity is such that specimens of these
dimensions cannot be measured, wider specimens or shorter support
spans, or both, may be used, provided the support span-to-depth ratio is at
least 14 to 1. All dimensions must be stated in the report (see also Note 6).
9. Conditioning
2°C (73.4 6 3.6°F) and 50 6 5 % relative humidity for not less
than 40 h prior to test in accordance with Procedure A of
Practice D 618 unless otherwise specified by contract or the
relevant ASTM material specification. Reference pre-test conditioning, to settle disagreements, shall apply tolerances of
61°C (1.8°F) and 62 % relative humidity.
9.2 Test Conditions—Conduct the tests at 23 6 2°C (73.4 6
3.6°F) and 50 6 5 % relative humidity unless otherwise
specified by contract or the relevant ASTM material specification. Reference testing conditions, to settle disagreements,
7.3 Laminated Thermosetting Materials and Sheet and
Plate Materials Used for Electrical Insulation, Including
Vulcanized Fiber and Glass-Bonded Mica—For paper-base
and fabric-base grades over 25.4 mm (1 in.) in nominal
thickness, the specimens shall be machined on both surfaces to
a depth of 25.4 mm. For glass-base and nylon-base grades,
specimens over 12.7 mm (1⁄2 in.) in nominal depth shall be
machined on both surfaces to a depth of 12.7 mm. The support
span-to-depth ratio shall be chosen such that failures occur in
the outer fibers of the specimens, due only to the bending
moment (see Note 8). Therefore, a ratio larger than 16:1 may
3
D 790
shall apply tolerances of 61°C (1.8°F) and 62 % relative
humidity.
outer surface of the test specimen has reached 0.05 mm/mm
(in./in.) or at break if break occurs prior to reaching the
maximum strain (Notes 9 and 10). The deflection at which this
strain will occur may be calculated by letting r equal 0.05
mm/mm (in./in.) in Eq 2:
10. Procedure
10.1 Procedure A:
10.1.1 Use an untested specimen for each measurement.
Measure the width and depth of the specimen to the nearest
0.03 mm (0.001 in.) at the center of the support span. For
specimens less than 2.54 mm (0.100 in.) in depth, measure the
depth to the nearest 0.003 mm (0.0005 in.). These measurements shall be made in accordance with Test Methods D 5947.
10.1.2 Determine the support span to be used as described in
Section 7 and set the support span to within 1 % of the
determined value.
10.1.3 For flexural fixtures that have continuously adjustable spans, measure the span accurately to the nearest 0.1 mm
(0.004 in.) for spans less than 63 mm (2.5 in.) and to the nearest
0.3 mm (0.012 in.) for spans greater than or equal to 63 mm
(2.5 in.). Use the actual measured span for all calculations. For
flexural fixtures that have fixed machined span positions, verify
the span distance the same as for adjustable spans at each
machined position. This distance becomes the span for that
position and is used for calculations applicable to all subsequent tests conducted at that position. See Annex A2 for
information on the determination of and setting of the span.
10.1.4 Calculate the rate of crosshead motion as follows and
set the machine for the rate of crosshead motion as calculated
by Eq 1:
R 5 ZL 2/6d
D 5 rL2/6d
(2)
where:
D = midspan deflection, mm (in.),
r = strain, mm/mm (in./in.),
L = support span, mm (in.), and
d = depth of beam, mm (in.).
NOTE 9—For some materials that do not yield or break within the 5 %
strain limit when tested by Procedure A, the increased strain rate allowed
by Procedure B (see 10.2) may induce the specimen to yield or break, or
both, within the required 5 % strain limit.
NOTE 10—Beyond 5 % strain, this test method is not applicable. Some
other mechanical property might be more relevant to characterize materials that neither yield nor break by either Procedure A or Procedure B
within the 5 % strain limit (for example, Test Method D 638 may be
considered).
10.2 Procedure B:
10.2.1 Use an untested specimen for each measurement.
10.2.2 Test conditions shall be identical to those described
in 10.1, except that the rate of straining of the outer surface of
the test specimen shall be 0.10 mm/mm (in./in.)/min.
10.2.3 If no break has occurred in the specimen by the time
the maximum strain in the outer surface of the test specimen
has reached 0.05 mm/mm (in./in.), discontinue the test (see
Note 10).
(1)
where:
R = rate of crosshead motion, mm (in.)/min,
L = support span, mm (in.),
d = depth of beam, mm (in.), and
Z = rate of straining of the outer fiber, mm/mm/min (in./
in./min). Z shall be equal to 0.01.
In no case shall the actual crosshead rate differ from that
calculated using Eq 1, by more than 610 %.
10.1.5 Align the loading nose and supports so that the axes
of the cylindrical surfaces are parallel and the loading nose is
midway between the supports. The parallelism of the apparatus
may be checked by means of a plate with parallel grooves into
which the loading nose and supports will fit when properly
aligned (see A2.3). Center the specimen on the supports, with
the long axis of the specimen perpendicular to the loading nose
and supports.
10.1.6 Apply the load to the specimen at the specified
crosshead rate, and take simultaneous load-deflection data.
Measure deflection either by a gage under the specimen in
contact with it at the center of the support span, the gage being
mounted stationary relative to the specimen supports, or by
measurement of the motion of the loading nose relative to the
supports. Load-deflection curves may be plotted to determine
the flexural strength, chord or secant modulus or the tangent
modulus of elasticity, and the total work as measured by the
area under the load-deflection curve. Perform the necessary toe
compensation (see Annex A1) to correct for seating and
indentation of the specimen and deflections in the machine.
10.1.7 Terminate the test when the maximum strain in the
11. Retests
11.1 Values for properties at rupture shall not be calculated
for any specimen that breaks at some obvious, fortuitous flaw,
unless such flaws constitute a variable being studied. Retests
shall be made for any specimen on which values are not
calculated.
12. Calculation
12.1 Toe compensation shall be made in accordance with
Annex A1 unless it can be shown that the toe region of the
curve is not due to the take-up of slack, seating of the
specimen, or other artifact, but rather is an authentic material
response.
12.2 Flexural Stress (sf)—When a homogeneous elastic
material is tested in flexure as a simple beam supported at two
points and loaded at the midpoint, the maximum stress in the
outer surface of the test specimen occurs at the midpoint. This
stress may be calculated for any point on the load-deflection
curve by means of the following equation (see Notes 11-13):
sf 5 3PL/2bd2
(3)
where:
s = stress in the outer fibers at midpoint, MPa (psi),
P = load at a given point on the load-deflection curve, N
(lbf),
L = support span, mm (in.),
b = width of beam tested, mm (in.), and
4
D 790
d = depth of beam tested, mm (in.).
NOTE 11—Eq 3 applies strictly to materials for which stress is linearly
proportional to strain up to the point of rupture and for which the strains
are small. Since this is not always the case, a slight error will be
introduced if Eq 3 is used to calculate stress for materials that are not true
Hookean materials. The equation is valid for obtaining comparison data
and for specification purposes, but only up to a maximum fiber strain of
5 % in the outer surface of the test specimen for specimens tested by the
procedures described herein.
NOTE 12—When testing highly orthotropic laminates, the maximum
stress may not always occur in the outer surface of the test specimen.7
Laminated beam theory must be applied to determine the maximum
tensile stress at failure. If Eq 3 is used to calculate stress, it will yield an
apparent strength based on homogeneous beam theory. This apparent
strength is highly dependent on the ply-stacking sequence of highly
orthotropic laminates.
NOTE 13—The preceding calculation is not valid if the specimen slips
excessively between the supports.
12.3 Flexural Stress for Beams Tested at Large Support
Spans (s f)—If support span-to-depth ratios greater than 16 to
1 are used such that deflections in excess of 10 % of the
support span occur, the stress in the outer surface of the
specimen for a simple beam can be reasonably approximated
with the following equation (see Note 14):
sf 5 ~3PL/2bd2!@1 1 6~D/L! 2 2 4~d/L!~D/L!#
NOTE—Curve a: Specimen that breaks before yielding.
Curve b: Specimen that yields and then breaks before the 5 % strain
limit.
Curve c: Specimen that neither yields nor breaks before the 5 % strain
limit.
(4)
where:
sf, P, L, b, and d are the same as for Eq 3, and
D = deflection of the centerline of the specimen at the
middle of the support span, mm (in.).
FIG. 2
NOTE 14—When large support span-to-depth ratios are used, significant
end forces are developed at the support noses which will affect the
moment in a simple supported beam. Eq 4 includes additional terms that
are an approximate correction factor for the influence of these end forces
in large support span-to-depth ratio beams where relatively large deflections exist.
Typical Curves of Flexural Stress (ßf) Versus Flexural
Strain (ef)
according to Eq 3 or Eq 4. Some materials may give a load
deflection curve that shows a break point, B, without a yield
point (Fig. 2, Curve a) in which case s fB = sfM. Other
materials may give a yield deflection curve with both a yield
and a break point, B (Fig. 2, Curve b). The flexural stress at
break may be calculated for these materials by letting P (in Eq
3 or Eq 4) equal this point, B.
12.7 Stress at a Given Strain—The stress in the outer
surface of a test specimen at a given strain may be calculated
in accordance with Eq 3 or Eq 4 by letting P equal the load read
from the load-deflection curve at the deflection corresponding
to the desired strain (for highly orthotropic laminates, see Note
12).
12.8 Flexural Strain, ef—Nominal fractional change in the
length of an element of the outer surface of the test specimen
at midspan, where the maximum strain occurs. It may be
calculated for any deflection using Eq 5:
12.4 Flexural Strength (sfM)—Maximum flexural stress
sustained by the test specimen (see Note 12) during a bending
test. It is calculated according to Eq 3 or Eq 4. Some materials
that do not break at strains of up to 5 % may give a load
deflection curve that shows a point at which the load does not
increase with an increase in strain, that is, a yield point (Fig. 2,
Curve B), Y. The flexural strength may be calculated for these
materials by letting P (in Eq 3 or Eq 4) equal this point, Y.
12.5 Flexural Offset Yield Strength—Offset yield strength is
the stress at which the stress-strain curve deviates by a given
strain (offset) from the tangent to the initial straight line portion
of the stress-strain curve. The value of the offset must be given
whenever this property is calculated.
ef 5 6Dd/L2
NOTE 15—This value may differ from flexural strength defined in 12.4.
Both methods of calculation are described in the annex to Test Method
D 638.
(5)
where:
ef = strain in the outer surface, mm/mm (in./in.),
D = maximum deflection of the center of the beam, mm
(in.),
d = depth, mm (in.).
D = maximum deflection of the center of the beam, mm
(in.),
12.6 Flexural Stress at Break (sfB )—Flexural stress at
break of the test specimen during a bending test. It is calculated
7
For a discussion of these effects, see Zweben, C., Smith, W. S., and Wardle, M.
W., “Test Methods for Fiber Tensile Strength, Composite Flexural Modulus and
Properties of Fabric-Reinforced Laminates, “ Composite Materials: Testing and
Design (Fifth Conference), ASTM STP 674, 1979, pp. 228–262.
5
D 790
curve. The selected points are to be chosen at two prespecified
stress or strain points in accordance with the appropriate
material specification or by customer contract. The chosen
stress or strain points used for the determination of the chord
modulus shall be reported. Calculate the chord modulus, Ef
using the following equation:
d = depth, mm (in.).
12.9 Modulus of Elasticity:
12.9.1 Tangent Modulus of Elasticity—The tangent modulus of elasticity, often called the “modulus of elasticity,” is the
ratio, within the elastic limit, of stress to corresponding strain.
It is calculated by drawing a tangent to the steepest initial
straight-line portion of the load-deflection curve and using Eq
6 (for highly anisotropic composites, see Note 16).
EB 5 L3m/4bd 3
where:
EB =
L =
b =
d =
m =
Ef 5 ~sf2 2 sf1!/~ef2 2 ef1!
where:
sf2 and sf1 are the flexural stresses, calculated from Eq 3 or
Eq 4 and measured at the predefined points on the load
deflection curve, and e f2 and
ef1 are the flexural strain values, calculated from Eq 5 and
measured at the predetermined points on the load deflection
curve.
12.10 Arithmetic Mean— For each series of tests, the
arithmetic mean of all values obtained shall be calculated to
three significant figures and reported as the “average value” for
the particular property in question.
12.11 Standard Deviation—The standard deviation (estimated) shall be calculated as follows and be reported to two
significant figures:
(6)
modulus of elasticity in bending, MPa (psi),
support span, mm (in.),
width of beam tested, mm (in.),
depth of beam tested, mm (in.), and
slope of the tangent to the initial straight-line portion
of the load-deflection curve, N/mm (lbf/in.) of deflection.
NOTE 16—Shear deflections can seriously reduce the apparent modulus
of highly anisotropic composites when they are tested at low span-todepth ratios.7 For this reason, a span-to-depth ratio of 60 to 1 is
recommended for flexural modulus determinations on these composites.
Flexural strength should be determined on a separate set of replicate
specimens at a lower span-to-depth ratio that induces tensile failure in the
outer fibers of the beam along its lower face. Since the flexural modulus
of highly anisotropic laminates is a critical function of ply-stacking
sequence, it will not necessarily correlate with tensile modulus, which is
not stacking-sequence dependent.
s 5 =~ (X 2 2 nX̄ 2! / ~n 2 1!
13. Report
13.1.1 Complete identification of the material tested, including type, source, manufacturer’s code number, form, principal
dimensions, and previous history (for laminated materials,
ply-stacking sequence shall be reported),
13.1.2 Direction of cutting and loading specimens, when
appropriate,
13.1.3 Conditioning procedure,
13.1.4 Depth and width of specimen,
13.1.5 Procedure used (A or B),
13.1.6 Support span length,
13.1.7 Support span-to-depth ratio if different than 16:1,
13.1.8 Radius of supports and loading noses if different than
5 mm,
13.1.9 Rate of crosshead motion,
13.1.10 Flexural strain at any given stress, average value
and standard deviation,
13.1.11 If a specimen is rejected, reason(s) for rejection,
13.1.12 Tangent, secant, or chord modulus in bending,
average value, standard deviation, and the strain level(s) used
if secant or chord modulus,
13.1.13 Flexural strength (if desired), average value, and
standard deviation,
13.1.14 Stress at any given strain up to and including 5 % (if
desired), with strain used, average value, and standard deviation,
13.1.15 Flexural stress at break (if desired), average value,
TABLE 2 Flexural Modulus
Mean, 103 psi
ABS
DAP thermoset
Cast acrylic
GR polyester
GR polycarbonate
SMC
338
485
810
816
1790
1950
Values Expressed in units of %
of 103 psi
VrA
VRB
rC
RD
4.79
2.89
13.7
3.49
5.52
10.9
7.69
7.18
16.1
4.20
5.52
13.8
13.6
8.15
38.8
9.91
15.6
30.8
21.8
20.4
45.4
11.9
15.6
39.1
(8)
where:
s = estimated standard deviation,
X = value of single observation,
n = number of observations, and
X̄ = arithmetic mean of the set of observations.
12.9.2 Secant Modulus— The secant modulus is the ratio of
stress to corresponding strain at any selected point on the
stress-strain curve, that is, the slope of the straight line that
joins the origin and a selected point on the actual stress-strain
curve. It shall be expressed in megapascals (pounds per square
inch). The selected point is chosen at a prespecified stress or
strain in accordance with the appropriate material specification
or by customer contract. It is calculated in accordance with Eq
6 by letting m equal the slope of the secant to the loaddeflection curve. The chosen stress or strain point used for the
determination of the secant shall be reported.
12.9.3 Chord Modulus (Ef)—The chord modulus may be
calculated from two discrete points on the load deflection
Material
(7)
A
Vr = within-laboratory coefficient of variation for the indicated material. It is
obtained by first pooling the within-laboratory standard deviations of the test
results from all of the participating laboratories: Sr = [[(s1)2 + ( s2)2 . . . + (sn)2]/n]
1/2 then Vr = (Sr divided by the overall average for the material) 3 100.
B
Vr = between-laboratory reproducibility, expressed as the coefficient of variation: SR = {Sr2 + SL2}1/2 where SL is the standard deviation of laboratory means.
Then: VR = (SR divided by the overall average for the material) 3 100.
C
r = within-laboratory critical interval between two test results = 2.8 3 Vr.
D
R = between-laboratory critical interval between two test results = 2.8 3 VR.
6
D 790
and standard deviation,
13.1.16 Type of behavior, whether yielding or rupture, or
both, or other observations, occurring within the 5 % strain
limit, and
13.1.17 Date of specific version of test used.
specific laboratories. The principles of 14.2-14.2.3 would then be valid for
such data.
14.2 Concept of “r” and “R” in Tables 1 and 2—If Sr and
SR have been calculated from a large enough body of data, and
for test results that were averages from testing five specimens
for each test result, then:
14.2.1 Repeatability— Two test results obtained within one
laboratory shall be judged not equivalent if they differ by more
than the r value for that material. r is the interval representing
the critical difference between two test results for the same
material, obtained by the same operator using the same
equipment on the same day in the same laboratory.
14.2.2 Reproducibility— Two test results obtained by different laboratories shall be judged not equivalent if they differ
by more than the R value for that material. R is the interval
representing the critical difference between two test results for
the same material, obtained by different operators using different equipment in different laboratories.
14.2.3 The judgments in 14.2.1 and 14.2.2 will have an
approximately 95 % (0.95) probability of being correct.
14.3 Bias—No statement may be made about the bias of
these test methods, as there is no standard reference material or
reference test method that is applicable.
14. Precision and Bias 8
14.1 Tables 1 and 2 are based on a round-robin test
conducted in 1984, in accordance with Practice E 691, involving six materials tested by six laboratories using Procedure A.
For each material, all the specimens were prepared at one
source. Each “test result” was the average of five individual
determinations. Each laboratory obtained two test results for
each material.
NOTE 17—Caution: The following explanations of r and R (14.214.2.3) are intended only to present a meaningful way of considering the
approximate precision of these test methods. The data given in Tables 2
and 3 should not be applied rigorously to the acceptance or rejection of
materials, as those data are specific to the round robin and may not be
representative of other lots, conditions, materials, or laboratories. Users of
these test methods should apply the principles outlined in Practice E 691
to generate data specific to their laboratory and materials, or between
15. Keywords
15.1 flexural properties; plastics; stiffness; strength
8
Supporting data are available from ASTM Headquarters. Request RR:
D20 – 1128.
ANNEXES
A1. TOE COMPENSATION
A1.1 In a typical stress-strain curve (see Fig. A1.1) there is
a toe region, AC, that does not represent a property of the
material. It is an artifact caused by a takeup of slack and
alignment or seating of the specimen. In order to obtain correct
values of such parameters as modulus, strain, and offset yield
point, this artifact must be compensated for to give the
corrected zero point on the strain or extension axis.
A1.2 In the case of a material exhibiting a region of
Hookean (linear) behavior (see Fig. A1.1), a continuation of
the linear (CD) region of the curve is constructed through the
zero-stress axis. This intersection (B) is the corrected zerostrain point from which all extensions or strains must be
measured, including the yield offset (BE), if applicable. The
elastic modulus can be determined by dividing the stress at any
point along the Line CD (or its extension) by the strain at the
same point (measured from Point B, defined as zero-strain).
A1.3 In the case of a material that does not exhibit any
linear region (see Fig. A1.2), the same kind of toe correction of
the zero-strain point can be made by constructing a tangent to
the maximum slope at the inflection Point H8. This is extended
to intersect the strain axis at Point B8, the corrected zero-strain
point. Using Point B8 as zero strain, the stress at any point (G8)
on the curve can be divided by the strain at that point to obtain
a secant modulus (slope of Line B8 G8). For those materials
with no linear region, any attempt to use the tangent through
NOTE—Some chart recorders plot the mirror image of this graph.
FIG. A1.1
Material with Hookean Region
7
D 790
yield point may result in unacceptable error.
NOTE—Some chart recorders plot the mirror image of this graph.
FIG. A1.2 Material with No Hookean Region
the inflection point as a basis for determination of an offset
A2. MEASURING AND SETTING SPAN
A2.1 For flexural fixtures that have adjustable spans, it is
important that the span between the supports is maintained
constant or the actual measured span is used in the calculation
of stress, modulus, and strain, and the loading nose or noses are
positioned and aligned properly with respect to the supports.
Some simple steps as follows can improve the repeatability of
your results when using these adjustable span fixtures.
FIG. A2.1 Markings on Fixed Specimen Supports
A2.2 Measurement of Span:
A2.2.1 This technique is needed to ensure that the correct
span, not an estimated span, is used in the calculation of
results.
A2.2.2 Scribe a permanent line or mark at the exact center
of the support where the specimen makes complete contact.
The type of mark depends on whether the supports are fixed or
rotatable (see Figs. A2.1 and A2.2).
A2.2.3 Using a vernier caliper with pointed tips that is
readable to at least 0.1 mm (0.004 in.), measure the distance
between the supports, and use this measurement of span in the
calculations.
FIG. A2.2 Markings on Rotatable Specimen Supports
A2.3 Setting the Span and Alignment of Loading
Nose(s)—To ensure a consistent day-to-day setup of the span
and ensure the alignment and proper positioning of the loading
nose, simple jigs should be manufactured for each of the
standard setups used. An example of a jig found to be useful is
shown in Fig. A2.3.
8
D 790
FIG. A2.3 Fixture Used to Set Loading Nose and Support Spacing and Alignment
SUMMARY OF CHANGES
This section identifies the location of selected changes to these test methods. For the convenience of the user,
Committee D20 has highlighted those changes that may impact the use of these test methods. This section may
also include descriptions of the changes or reasons for the changes, or both.
D 790 – 02:
(1) Revised 9.1 and 9.2.
D 790 – 00:
(1) Revised 12.1.
D 790 – 99:
(1) Revised 10.1.3.
D 790 – 98:
(1) Section 4.2 was rewritten extensively to bring this standard
closer to ISO 178.
(2) Fig. 2 was added to clarify flexural behaviors that may be
observed and to define what yielding and breaking behaviors
look like, as well as the appropriate place to select these points
on the stress strain curve.
(www.astm.org).
9
Designation: D 256 – 00e1
Standard Test Methods for
Determining the Izod Pendulum Impact Resistance of
Plastics1
e1 NOTE—Note 2 was editorially added in April 2002. Title of Table 1 was editorially corrected in April 2002.
1. Scope *
1.1 These test methods cover the determination of the
resistance of plastics to “standardized” (see Note 1) pendulumtype hammers, mounted in “standardized” machines, in breaking standard specimens with one pendulum swing (see Note 2).
The standard tests for these test methods require specimens
made with a milled notch (see Note 3). In Test Methods A, C,
and D, the notch produces a stress concentration that increases
the probability of a brittle, rather than a ductile, fracture. In
Test Method E, the impact resistance is obtained breakage by
flexural shock as indicated by the energy extracted from by
reversing the notched specimen 180° in the clamping vise. The
results of all test methods are reported in terms of energy
absorbed per unit of specimen width or per unit of crosssectional area under the notch. (See Note 4.)
of a plastic’s “notch sensitivity” may be obtained with Test Method D by
comparing the energies to break specimens having different radii at the
base of the notch.
NOTE 4—Caution must be exercised in interpreting the results of these
standard test methods. The following testing parameters may affect test
results significantly:
Method of fabrication, including but not limited to processing
technology, molding conditions, mold design, and thermal
treatments;
Method of notching;
Speed of notching tool;
Design of notching apparatus;
Quality of the notch;
Time between notching and test;
Test specimen thickness,
Test specimen width under notch, and
Environmental conditioning.
standard. The values given in parentheses are for information
only.
NOTE 1—The machines with their pendulum-type hammers have been
“standardized” in that they must comply with certain requirements,
including a fixed height of hammer fall that results in a substantially fixed
velocity of the hammer at the moment of impact. However, hammers of
different initial energies (produced by varying their effective weights) are
recommended for use with specimens of different impact resistance.
Moreover, manufacturers of the equipment are permitted to use different
lengths and constructions of pendulums with possible differences in
pendulum rigidities resulting. (See Section 5.) Be aware that other
differences in machine design may exist. The specimens are “standardized” in that they are required to have one fixed length, one fixed depth,
and one particular design of milled notch. The width of the specimens is
permitted to vary between limits.
NOTE 2—Results generated using pendulums that utilize a load cell to
record the impact force and thus impact energy, may not be equivalent to
results that are generated using manually or digitally encoded testers that
measure the energy remaining in the pendulum after impact.
NOTE 3—The notch in the Izod specimen serves to concentrate the
stress, minimize plastic deformation, and direct the fracture to the part of
the specimen behind the notch. Scatter in energy-to-break is thus reduced.
However, because of differences in the elastic and viscoelastic properties
of plastics, response to a given notch varies among materials. A measure
NOTE 5—These test methods resemble ISO 180:1993 in regard to title
only. The contents are significantly different.
2.1 ASTM Standards:
D 3641 Practice for Injection Molding Test Specimens of
Thermoplastics Molding Extrusion Materials3
D 4066 Specification for Nylon Injection and Extrusion
Materials3
1
These test methods are under the jurisdiction of ASTM Committee D20 on
Plastics and are the direct responsibility of Subcommittee D20.10 on Mechanical
Properties.
Current edition approved Nov. 10, 2000. Published January 2001. Originally
published as D 256 – 26T. Last previous edition D 256 – 97.
2
3
1
D 256
TABLE 1 Precision Data, Test Method A—Reversed Notch Izod
NOTE 1—Values in ft·lbf/in. of width (J/m of width).
NOTE 2—See Footnote 10.
Material
Phenolic
Acetal
Reinforced nylon
Polypropylene
ABS
Polycarbonate
Average
0.57 (30.4)
1.45 (77.4)
1.98 (105.7)
2.66 (142.0)
10.80 (576.7)
16.40 (875.8)
SrA
0.024
0.075
0.083
0.154
0.136
0.295
(1.3)
(4.0)
(4.4)
(8.2)
(7.3)
(15.8)
SRB
IrC
IRD
Number of
Laboratories
0.076 (4.1)
0.604 (32.3)
0.245 (13.1)
0.573 (30.6)
0.585 (31.2)
1.056 (56.4)
0.06 (3.2)
0.21 (11.2)
0.23 (12.3)
0.43 (23.0)
0.38 (20.3)
0.83 (44.3)
0.21 (11.2)
1.70 (90.8)
0.69 (36.8)
1.62 (86.5)
1.65 (88.1)
2.98 (159.1)
19
9
15
24
25
25
A
Sr = within-laboratory standard deviation of the average.
SR = between-laboratories standard deviation of the average.
C
Ir = 2.83 Sr.
D
IR = 2.83 SR.
B
4.1.3 Test Method D provides a measure of the notch
sensitivity of a material. The stress-concentration at the notch
increases with decreasing notch radius.
4.1.3.1 For a given system, greater stress concentration
results in higher localized rates-of-strain. Since the effect of
strain-rate on energy-to-break varies among materials, a measure of this effect may be obtained by testing specimens with
different notch radii. In the Izod-type test it has been demonstrated that the function, energy-to-break versus notch radius,
is reasonably linear from a radius of 0.03 to 2.5 mm (0.001 to
0.100 in.), provided that all specimens have the same type of
break. (See 5.8 and 22.1.)
4.1.3.2 For the purpose of this test, the slope, b (see 22.1),
of the line between radii of 0.25 and 1.0 mm (0.010 and 0.040
in.) is used, unless tests with the 1.0-mm radius give “nonbreak” results. In that case, 0.25 and 0.50-mm (0.010 and
0.020-in.) radii may be used. The effect of notch radius on the
impact energy to break a specimen under the conditions of this
test is measured by the value b. Materials with low values of b,
whether high or low energy-to-break with the standard notch,
are relatively insensitive to differences in notch radius; while
the energy-to-break materials with high values of b is highly
dependent on notch radius. The parameter b cannot be used in
design calculations but may serve as a guide to the designer
and in selection of materials.
4.2 Test Method E is similar to Test Method A, except that
the specimen is reversed in the vise of the machine 180° to the
usual striking position, such that the striker of the apparatus
impacts the specimen on the face opposite the notch. (See Fig.
1, Fig. 2.) Test Method E is used to give an indication of the
unnotched impact resistance of plastics; however, results obtained by the reversed notch method may not always agree with
those obtained on a completely unnotched specimen. (See
28.1.)7,8
D 4812 Test Methods for Unnoticed Cantilever Beam Impact Strength of Plastics4
E 691 Practice for Conducting an Interlaboratory Test Program to Determine the Precision of Test Methods5
2.2 ISO Standard:
ISO 180:1993 Plastics—Determination of Izod Impact
Strength of Rigid Materials6
3. Terminology
3.1 Definitions— For definitions related to plastics see
Terminology D 883.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 cantilever—a projecting beam clamped at only one
end.
3.2.2 notch sensitivity—a measure of the variation of impact
energy as a function of notch radius.
4. Types of Tests
4.1 Four similar methods are presented in these test methods. (See Note 6.) All test methods use the same testing
machine and specimen dimensions. There is no known means
for correlating the results from the different test methods.
NOTE 6—Test Method B for Charpy has been removed and is being
revised under a new standard.
4.1.1 In Test Method A, the specimen is held as a vertical
cantilever beam and is broken by a single swing of the
pendulum. The line of initial contact is at a fixed distance from
the specimen clamp and from the centerline of the notch and on
the same face as the notch.
4.1.2 Test Method C is similar to Test Method A, except for
the addition of a procedure for determining the energy expended in tossing a portion of the specimen. The value reported
is called the “estimated net Izod impact resistance.” Test
Method C is preferred over Test Method A for materials that
have an Izod impact resistance of less than 27 J/m (0.5
ft·lbf/in.) under notch. (See Appendix X4 for optional units.)
The differences between Test Methods A and C become
unimportant for materials that have an Izod impact resistance
higher than this value.
5.1 Before proceeding with these test methods, reference
should be made to the specification of the material being tested.
Any test specimen preparation, conditioning, dimensions, and
7
Supporting data giving results of the interlaboratory tests are available from
ASTM Headquarters. Request RR: D20-1021.
8
Supporting data giving results of the interlaboratory tests are available from
ASTM Headquarters. Request RR: D20-1026.
4
6
Available from American National Standards Institute, 11 W. 42nd St., 13th
5
2
D 256
5.3.4 Energy to bend the specimen;
5.3.5 Energy to produce vibration in the pendulum arm;
5.3.6 Energy to produce vibration or horizontal movement
of the machine frame or base;
5.3.7 Energy to overcome friction in the pendulum bearing
and in the excess energy indicating mechanism, and to overcome windage (pendulum air drag);
5.3.8 Energy to indent or deform plastically the specimen at
the line of impact; and
5.3.9 Energy to overcome the friction caused by the rubbing
of the striker (or other part of the pendulum) over the face of
the bent specimen.
5.4 For relatively brittle materials, for which fracture propagation energy is small in comparison with the fracture initiation
energy, the indicated impact energy absorbed is, for all
practical purposes, the sum of factors 5.3.1 and 5.3.3. The toss
correction (see 5.3.3) may represent a very large fraction of the
total energy absorbed when testing relatively dense and brittle
materials. Test Method C shall be used for materials that have
an Izod impact resistance of less than 27 J/m (0.5 ft·lbf/in.).
(See Appendix X4 for optional units.) The toss correction
obtained in Test Method C is only an approximation of the toss
error, since the rotational and rectilinear velocities may not be
the same during the re-toss of the specimen as for the original
toss, and because stored stresses in the specimen may have
been released as kinetic energy during the specimen fracture.
5.5 For tough, ductile, fiber filled, or cloth-laminated materials, the fracture propagation energy (see 5.3.2) may be large
compared to the fracture initiation energy (see 5.3.1). When
testing these materials, factors (see 5.3.2, 5.3.5, and 5.3.9) can
become quite significant, even when the specimen is accurately
machined and positioned and the machine is in good condition
with adequate capacity. (See Note 7.) Bending (see 5.3.4) and
indentation losses (see 5.3.8) may be appreciable when testing
soft materials.
FIG. 2 Relationship of Vise, Specimen, and Striking Edge to Each
Other for Test Method E
NOTE 7—Although the frame and base of the machine should be
sufficiently rigid and massive to handle the energies of tough specimens
without motion or excessive vibration, the design must ensure that the
center of percussion be at the center of strike. Locating the striker
precisely at the center of percussion reduces vibration of the pendulum
arm when used with brittle specimens. However, some losses due to
pendulum arm vibration, the amount varying with the design of the
pendulum, will occur with tough specimens, even when the striker is
properly positioned.
FIG. 1 Relationship of Vise, Specimen, and Striking Edge to Each
Other for Izod Test Methods A and C
5.6 In a well-designed machine of sufficient rigidity and
mass, the losses due to factors 5.3.6 and 5.3.7 should be very
small. Vibrational losses (see 5.3.6) can be quite large when
wide specimens of tough materials are tested in machines of
insufficient mass, not securely fastened to a heavy base.
5.7 With some materials, a critical width of specimen may
be found below which specimens will appear ductile, as
evidenced by considerable drawing or necking down in the
region behind the notch and by a relatively high-energy
absorption, and above which they will appear brittle as
evidenced by little or no drawing down or necking and by a
relatively low-energy absorption. Since these methods permit a
variation in the width of the specimens, and since the width
dictates, for many materials, whether a brittle, low-energy
break or a ductile, high energy break will occur, it is necessary
testing parameters covered in the materials specification shall
take precedence over those mentioned in these test methods. If
there is no material specification, then the default conditions
apply.
5.2 The excess energy pendulum impact test indicates the
energy to break standard test specimens of specified size under
stipulated parameters of specimen mounting, notching, and
pendulum velocity-at-impact.
5.3 The energy lost by the pendulum during the breakage of
the specimen is the sum of the following:
5.3.1 Energy to initiate fracture of the specimen;
5.3.2 Energy to propagate the fracture across the specimen;
5.3.3 Energy to throw the free end (or ends) of the broken
specimen (“toss correction”);
3
D 256
pendulum holding and releasing mechanism and a pointer and
dial mechanism for indicating the excess energy remaining in
the pendulum after breaking the specimen. Optionally, an
electronic digital display or computer can be used in place of
the dial and pointer to measure the energy loss and indicate the
breaking energy of the specimen.
6.2 A jig for positioning the specimen in the vise and graphs
or tables to aid in the calculation of the correction for friction
and windage also should be included. One type of machine is
shown in Fig. 3. One design of specimen-positioning jig is
illustrated in Fig. 4. Detailed requirements are given in
subsequent paragraphs. General test methods for checking and
calibrating the machine are given in Appendix X1. Additional
instructions for adjusting a particular machine should be
supplied by the manufacturer.
6.3 The pendulum shall consist of a single or multimembered arm with a bearing on one end and a head,
containing the striker, on the other. The arm must be sufficiently rigid to maintain the proper clearances and geometric
relationships between the machine parts and the specimen and
to minimize vibrational energy losses that are always included
in the measured impact resistance. Both simple and compound
pendulum designs may comply with this test method.
6.4 The striker of the pendulum shall be hardened steel and
shall be a cylindrical surface having a radius of curvature of
0.80 6 0.20 mm (0.031 6 0.008 in.) with its axis horizontal
and perpendicular to the plane of swing of the pendulum. The
line of contact of the striker shall be located at the center of
percussion of the pendulum within 62.54 mm (60.100 in.)
(See Note 9.) Those portions of the pendulum adjacent to the
cylindrical striking edge shall be recessed or inclined at a
suitable angle so that there will be no chance for other than this
cylindrical surface coming in contact with the specimen during
the break.
that the width be stated in the specification covering that
material and that the width be reported along with the impact
resistance. In view of the preceding, one should not make
comparisons between data from specimens having widths that
differ by more than a few mils.
5.8 The type of failure for each specimen shall be recorded
as one of the four categories listed as follows:
C
H
P
NB
Complete Break—A break where the specimen
separates into two or more pieces.
Hinge Break—An incomplete break, such that one
part of the specimen cannot support itself above
the horizontal when the other part is held vertically
(less than 90° included angle).
Partial Break—An incomplete break that does not
meet the definition for a hinge break but has fractured at least 90 % of the distance between the
vertex of the notch and the opposite side.
Non-Break—An incomplete break where the fracture extends less than 90 % of the distance between the vertex of the notch and the opposite
side.
For tough materials, the pendulum may not have the energy
necessary to complete the breaking of the extreme fibers and
toss the broken piece or pieces. Results obtained from “nonbreak” specimens shall be considered a departure from standard and shall not be reported as a standard result. Impact
resistance cannot be directly compared for any two materials
that experience different types of failure as defined in the test
method by this code. Averages reported must likewise be
derived from specimens contained within a single failure
category. This letter code shall suffix the reported impact
identifying the types of failure associated with the reported
value. If more than one type of failure is observed for a sample
material, then the report will indicate the average impact
resistance for each type of failure, followed by the percent of
the specimens failing in that manner and suffixed by the letter
code.
5.9 The value of the impact methods lies mainly in the areas
of quality control and materials specification. If two groups of
specimens of supposedly the same material show significantly
different energy absorptions, types of breaks, critical widths, or
critical temperatures, it may be assumed that they were made
of different materials or were exposed to different processing or
conditioning environments. The fact that a material shows
twice the energy absorption of another under these conditions
of test does not indicate that this same relationship will exist
under another set of test conditions. The order of toughness
may even be reversed under different testing conditions.
NOTE 8—A documented discrepancy exists between manual and digital
impact testers, primarily with thermoset materials, including phenolics,
having an impact value of less than 54 J/m (1 ft-lb/in.). Comparing data
on the same material, tested on both manual and digital impact testers,
may show the data from the digital tester to be significantly lower than
data from a manual tester. In such cases a correlation study may be
necessary to properly define the true relationship between the instruments.
TEST METHOD A—CANTILEVER BEAM TEST
6. Apparatus
6.1 The machine shall consist of a massive base on which is
mounted a vise for holding the specimen and to which is
connected, through a rigid frame and bearings, a pendulumtype hammer. (See 6.2.) The machine must also have a
FIG. 3 Cantilever Beam (Izod-Type) Impact Machine
4
D 256
ft·lbf). This pendulum shall be used with all specimens that
extract less than 85 % of this energy. Heavier pendulums shall
be provided for specimens that require more energy to break.
These may be separate interchangeable pendulums or one basic
pendulum to which extra pairs of equal calibrated weights may
be rigidly attached to opposite sides of the pendulum. It is
imperative that the extra weights shall not significantly change
the position of the center of percussion or the free-hanging rest
point of the pendulum (that would consequently take the
machine outside of the allowable calibration tolerances). A
range of pendulums having energies from 2.7 to 21.7 J (2 to 16
ft·lbf) has been found to be sufficient for use with most plastic
specimens and may be used with most machines. A series of
pendulums such that each has twice the energy of the next will
be found convenient. Each pendulum shall have an energy
within 6 0.5 % of its nominal capacity.
6.8 A vise shall be provided for clamping the specimen
rigidly in position so that the long axis of the specimen is
vertical and at right angles to the top plane of the vise. (See Fig.
1.) This top plane shall bisect the angle of the notch with a
tolerance of 0.12 mm (0.005 in.). Correct positioning of the
specimen is generally done with a jig furnished with the
machine. The top edges of the fixed and moveable jaws shall
have a radius of 0.25 6 0.12 mm (0.010 6 0.005 in.). For
specimens whose thickness approaches the lower limiting
value of 3.00 mm (0.118 in.), means shall be provided to
prevent the lower half of the specimen from moving during the
clamping or testing operations (see Fig. 4 and Note 11.)
FIG. 4 Jig for Positioning Specimen for Clamping
NOTE 9—The distance from the axis of support to the center of
percussion may be determined experimentally from the period of small
amplitude oscillations of the pendulum by means of the following
equation:
L 5 ~g/4p 2!p 2
NOTE 11—Some plastics are sensitive to clamping pressure; therefore,
cooperating laboratories should agree upon some means of standardizing
the clamping force. One method is using a torque wrench on the screw of
the specimen vise. If the faces of the vise or specimen are not flat and
parallel, a greater sensitivity to clamping pressure may be evident. See the
calibration procedure in Appendix X2 for adjustment and correction
instructions for faulty instruments.
where:
L = distance from the axis of support to the center of percussion, m
(or ft),
g = local gravitational acceleration (known to an accuracy of one
part in one thousand), m/s2 (or ft/s 2),
p = 3.1416 (4p 2 = 39.48), and
p = period, s, of a single complete swing (to and fro) determined by
averaging at least 20 consecutive and uninterrupted swings. The
angle of swing shall be less than 5° each side of center.
6.9 When the pendulum is free hanging, the striking surface
shall come within 0.2 % of scale of touching the front face of
a standard specimen. During an actual swing this element shall
make initial contact with the specimen on a line 22.00 6 0.05
mm (0.87 6 0.002 in.) above the top surface of the vise.
6.10 Means shall be provided for determining energy remaining in the pendulum after breaking the specimen. This
may consist of a pointer and dial mechanism which indicate the
height of rise of the pendulum beyond the point of impact in
terms of energy removed from that specific pendulum. Since
the indicated remaining energy must be corrected for
pendulum-bearing friction, pointer friction, pointer inertia, and
pendulum windage, instructions for making these corrections
are included in 10.3 and Annex A1 and Annex A2. Optionally,
an electronic digital display or computer can be used in place
of the dial and pointer to measure the energy loss and indicate
the breaking energy of the specimen. If the electronic display
does not automatically correct for windage and friction, it shall
be incumbent for the operator to determine the energy loss
manually. (See Note 12.)
6.5 The position of the pendulum holding and releasing
mechanism shall be such that the vertical height of fall of the
striker shall be 610 6 2 mm (24.0 6 0.1 in.). This will produce
a velocity of the striker at the moment of impact of approximately 3.5 m (11.4 ft)/s. (See Note 10.) The mechanism shall
be so constructed and operated that it will release the pendulum
without imparting acceleration or vibration to it.
NOTE 10—
V 5 ~2gh!0.5
where:
V = velocity of the striker at the moment of impact (m/s),
g = local gravitational acceleration (m/s2), and
h = vertical height of fall of the striker (m).
This assumes no windage or friction.
6.6 The effective length of the pendulum shall be between
0.33 and 0.40 m (12.8 and 16.0 in.) so that the required
elevation of the striker may be obtained by raising the
pendulum to an angle between 60 and 30° above the horizontal.
6.7 The machine shall be provided with a basic pendulum
capable of delivering an energy of 2.7 6 0.14 J (2.00 6 0.10
NOTE 12—Many digital indicating systems automatically correct for
windage and friction. The equipment manufacturer may be consulted for
details concerning how this is performed, or if it is necessary to determine
5
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result in an equivalent accuracy. Appendix X1 also describes a
dynamic test for checking certain features of the machine and
specimen.
the means for manually calculating the energy loss due to windage and
friction.
6.11 The vise, pendulum, and frame shall be sufficiently
rigid to maintain correct alignment of the hammer and specimen, both at the moment of impact and during the propagation
of the fracture, and to minimize energy losses due to vibration.
The base shall be sufficiently massive that the impact will not
cause it to move. The machine shall be so designed, constructed, and maintained that energy losses due to pendulum air
drag (windage), friction in the pendulum bearings, and friction
and inertia in the excess energy-indicating mechanism are held
to a minimum.
6.12 A check of the calibration of an impact machine is
difficult to make under dynamic conditions. The basic parameters are normally checked under static conditions; if the
machine passes the static tests, then it is assumed to be
accurate. The calibration procedure in Appendix X2 should be
used to establish the accuracy of the equipment. However, for
some machine designs it might be necessary to change the
recommended method of obtaining the required calibration
measurements. Other methods of performing the required
checks may be substituted, provided that they can be shown to
A
B
C
D
E
7. Test Specimens
7.1 The test specimens shall conform to the dimensions and
geometry of Fig. 5, except as modified in accordance with 7.2,
7.3, 7.4, and 7.5. To ensure the correct contour and conditions
of the specified notch, all specimens shall be notched as
directed in Section 8.
7.2 Molded specimens shall have a width between 3.0 and
12.7 mm (0.118 and 0.500 in.). Use the specimen width as
specified in the material specification or as agreed upon
between the supplier and the customer. All specimens having
one dimension less than 12.7 mm (0.500 in.) shall have the
notch cut on the shorter side. Otherwise, all compressionmolded specimens shall be notched on the side parallel to the
direction of application of molding pressure. (Due to the draft
of the mold, the notched surface and the opposite surface may
not be parallel in molded specimens. Therefore, it is essential
that the notched surface be machined parallel to its opposite
surface within 0.025 mm (0.001 in.), removing a minimum of
10.16 6 0.05
32 6 1
64 6 2
0.25R 6 0.05
12.7 6 0.2
0.400 6 0.002
1.26 6 0.04
2.50 6 0.08
0.010R 6 0.002
0.500 6 0.008
FIG. 5 Dimensions of Izod-Type Test Specimen
6
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specimens shall be noted in the report of test results.
7.4.2 Care must be taken to select a solvent or adhesive that
will not affect the impact resistance of the material under test.
If solvents or solvent-containing adhesives are employed, a
conditioning procedure shall be established to ensure complete
removal of the solvent prior to test.
7.5 Each specimen shall be free of twist (see Note 13) and
shall have mutually perpendicular pairs of plane parallel
surfaces and free from scratches, pits, and sink marks. The
specimens shall be checked for compliance with these requirements by visual observation against straightedges, squares, and
flat plates, and by measuring with micrometer calipers. Any
specimen showing observable or measurable departure from
one or more of these requirements shall be rejected or
machined to the proper size and shape before testing.
material in the process, so as to remain within the allowable
tolerance for the specimen depth). (See Fig. 5.)
7.2.1 Extreme care must be used in handling specimens less
than 6.4 mm (0.250 in.) wide. Such specimens must be
accurately positioned and supported to prevent twist or lateral
buckling during the test. Some materials, furthermore, are very
sensitive to clamping pressure (see Note 11).
7.2.2 A critical investigation of the mechanics of impact
testing has shown that tests made upon specimens under 6.4
mm (0.250 in.) wide absorb more energy due to crushing,
bending, and twisting than do wider specimens. Therefore,
specimens 6.4 mm (0.250 in.) or over in width are recommended. The responsibility for determining the minimum
specimen width shall be the investigator’s, with due reference
to the specification for that material.
7.2.3 Material specification should be consulted for preferred molding conditions. The type of mold and molding
machine used and the flow behavior in the mold cavity will
influence the impact resistance obtained. A specimen taken
from one end of a molded plaque may give different results
than a specimen taken from the other end. Cooperating
laboratories should therefore agree on standard molds conforming to the material specification. Practice D 3641 can be
used as a guide for general molding tolerances, but refer to the
material specification for specific molding conditions.
7.2.4 The impact resistance of a plastic material may be
different if the notch is perpendicular to, rather than parallel to,
the direction of molding. The same is true for specimens cut
with or across the grain of an anisotropic sheet or plate.
7.3 For sheet materials, the specimens shall be cut from the
sheet in both the lengthwise and crosswise directions unless
otherwise specified. The width of the specimen shall be the
thickness of the sheet if the sheet thickness is between 3.0 and
12.7 mm (0.118 and 0.500 in.). Sheet material thicker than 12.7
mm shall be machined down to 12.7 mm. Specimens with a
12.7-mm square cross section may be tested either edgewise or
flatwise as cut from the sheet. When specimens are tested
flatwise, the notch shall be made on the machined surface if the
specimen is machined on one face only. When the specimen is
cut from a thick sheet, notation shall be made of the portion of
the thickness of the sheet from which the specimen was cut, for
example, center, top, or bottom surface.
7.4 The practice of cementing, bolting, clamping, or otherwise combining specimens of substandard width to form a
composite test specimen is not recommended and should be
avoided since test results may be seriously affected by interface
effects or effects of solvents and cements on energy absorption
of composite test specimens, or both. However, if Izod test data
on such thin materials are required when no other means of
preparing specimens are available, and if possible sources of
error are recognized and acceptable, the following technique of
preparing composites may be utilized.
7.4.1 The test specimen shall be a composite of individual
thin specimens totaling 6.4 to 12.7 mm (0.250 to 0.500 in.) in
width. Individual members of the composite shall be accurately
aligned with each other and clamped, bolted, or cemented
together. The composite shall be machined to proper dimensions and then notched. In all such cases the use of composite
NOTE 13—A specimen that has a slight twist to its notched face of 0.05
mm (0.002 in.) at the point of contact with the pendulum striking edge will
be likely to have a characteristic fracture surface with considerable greater
fracture area than for a normal break. In this case the energy to break and
toss the broken section may be considerably larger (20 to 30 %) than for
a normal break. A tapered specimen may require more energy to bend it
in the vise before fracture.
8. Notching Test Specimens
8.1 Notching shall be done on a milling machine, engine
lathe, or other suitable machine tool. Both the feed speed and
the cutter speed shall be constant throughout the notching
operation (see Note 14). Provision for cooling the specimen
with either a liquid or gas coolant is recommended. A singletooth cutter shall be used for notching the specimen, unless
notches of an equivalent quality can be produced with a
multi-tooth cutter. Single-tooth cutters are preferred because of
the ease of grinding the cutter to the specimen contour and
because of the smoother cut on the specimen. The cutting edge
shall be carefully ground and honed to ensure sharpness and
freedom from nicks and burrs. Tools with no rake and a work
relief angle of 15 to 20° have been found satisfactory.
NOTE 14—For some thermoplastics, cutter speeds from 53 to 150
m/min (175 to 490 ft/min) at a feed speed of 89 to 160 mm/min (3.5 to 6.3
in./min) without a water coolant or the same cutter speeds at a feed speed
of from 36 to 160 mm/min (1.4 to 6.3 in./min) with water coolant
produced suitable notches.
8.2 Specimens may be notched separately or in a group.
However, in either case an unnotched backup or “dummy bar”
shall be placed behind the last specimen in the sample holder
to prevent distortion and chipping by the cutter as it exits from
the last test specimen.
8.3 The profile of the cutting tooth or teeth shall be such as
to produce a notch of the contour and depth in the test
specimen as specified in Fig. 5 (see Note 15). The included
angle of the notch shall be 45 6 1° with a radius of curvature
at the apex of 0.25 6 0.05 mm (0.010 6 0.002 in.). The plane
bisecting the notch angle shall be perpendicular to the face of
the test specimen within 2°.
NOTE 15—There is evidence that notches in materials of widely varying
physical dimensions may differ in contour even when using the same
cutter. If the notch in the specimen should take the contour of the cutter,
then the contour of the tip of the cutter may be checked instead of the
notch in the specimen for single-tooth cutters. Under the same condition,
7
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tions are not selected.9 The notching parameters used shall not
alter the physical state of the material such as by raising the
temperature of a thermoplastic above its glass transition
temperature. In general, high cutter speeds, slow feed rates, and
lack of coolant induce more thermal damage than a slow cutter
speed, fast feed speed, and the use of a coolant. Too high a feed
speed/cutter speed ratio, however, may cause impacting and
multi-tooth cutters may be checked by measuring the contour of a strip of
soft metal shim inserted between two specimens for notching.
8.4 The depth of the plastic material remaining in the
specimen under the notch shall be 10.16 6 0.05 mm (0.400 6
0.002 in.). This dimension shall be measured, with a micrometer or other suitable measuring device. (See Fig. 6.)
8.5 Cutter speed and feed speed should be chosen appropriate for the material being tested since the quality of the notch
may be adversely affected by thermal deformations and
stresses induced during the cutting operation if proper condi-
NOTE
NOTE
NOTE
NOTE
NOTE
NOTE
NOTE
9
Supporting data are available from ASTM Headquarters. Request RR: D201066.
1—These views not to scale.
2—Micrometer to be satin-chrome finished with friction thimble.
3—Special anvil for micrometer caliper 0 to 25.4 mm range (50.8 mm frame) (0 to 1 in. range (2-in. frame)).
4—Anvil to be oriented with respect to frame as shown.
5—Anvil and spindle to have hardened surfaces.
6—Range: 0 to 25.4 mm (0 to 1 in. in thousandths of an inch).
7—Adjustment must be at zero when spindle and anvil are in contact.
FIG. 6 Early (ca. 1970) Version of a Notch-Depth Micrometer
8
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cracking of the specimen. The range of cutter speed/feed ratios
possible to produce acceptable notches can be extended by the
use of a suitable coolant. (See Note 16.) In the case of new
types of plastics, it is necessary to study the effect of variations
in the notching conditions. (See Note 17.)
pendulum that is expected to break each specimen in the group
with a loss of not more than 85 % of its energy (see Note 19).
Check the machine with the proper pendulum in place for
conformity with the requirements of Section 6 before starting
the tests. (See Appendix X1.)
NOTE 16—Water or compressed gas is a suitable coolant for many
plastics.
NOTE 17—Embedded thermocouples, or another temperature measuring device, can be used to determine the temperature rise in the material
near the apex of the notch during machining. Thermal stresses induced
during the notching operation can be observed in transparent materials by
viewing the specimen at low magnification between crossed polars in
monochromatic light.
NOTE 19—Ideally an impact test would be conducted at a constant test
velocity. In a pendulum-type test, the velocity decreases as the fracture
progresses. For specimens that have an impact energy approaching the
capacity of the pendulum there is insufficient energy to complete the break
and toss. By avoiding the higher 15 % scale energy readings, the velocity
of the pendulum will not be reduced below 1.3 m/s (4.4 ft/s). On the other
hand, the use of too heavy a pendulum would reduce the sensitivity of the
reading.
8.6 The specimen notch produced by each cutter will be
examined, at a minimum, after every 500 notches. The notch in
the specimen, made of the material to be tested, shall be
inspected and verified. One procedure for the inspection and
verification of the notch is presented in Appendix X1. Each
type of material being notched must be inspected and verified
at that time. If the angle or radius does not fall within the
specified limits for materials of satisfactory machining characteristics, then the cutter shall be replaced with a newly
sharpened and honed one. (See Note 18.)
10.3 If the machine is equipped with a mechanical pointer
and dial, perform the following operations before testing the
specimens:
10.3.1 With the excess energy indicating pointer in its
normal starting position but without a specimen in the vise,
release the pendulum from its normal starting position and note
the position the pointer attains after the swing as one reading of
Factor A.
10.3.2 Without resetting the pointer, raise the pendulum and
release again. The pointer should move up the scale an
additional amount. Repeat (10.3.2) until a swing causes no
additional movement of the pointer and note the final reading
as one reading of Factor B (see Note 20).
10.3.3 Repeat the preceding two operations several times
and calculate and record the average A and B readings.
NOTE 18—A carbide-tipped or industrial diamond-tipped notching
cutter is recommended for longer service life.
9. Conditioning
2°C (73 6 3.6°F) and 50 6 5 % relative humidity for not less
than 40 h after notching and prior to testing in accordance with
Procedure A of Practice D 618, unless it can be documented
(between supplier and customer) that a shorter conditioning
time is sufficient for a given material to reach equilibrium of
impact resistance.
9.1.1 Note that for some hygroscopic materials, such as
nylons, the material specifications (for example, Specification
D 4066) call for testing “dry as-molded specimens.” Such
requirements take precedence over the above routine preconditioning to 50 % relative humidity and require sealing the
specimens in water vapor-impermeable containers as soon as
molded and not removing them until ready for testing.
9.2 Test Conditions—Conduct tests in the standard laboratory atmosphere of 23 6 2°C (73 6 3.6°F) and 50 6 5 %
relative humidity, unless otherwise specified in the material
specification or by customer requirements. In cases of disagreement, the tolerances shall be 61°C (61.8°F) and 6 2 %
relative humidity.
NOTE 20—Factor B is an indication of the energy lost by the pendulum
to friction in the pendulum bearings and to windage. The difference A – B
is an indication of the energy lost to friction and inertia in the excess
energy indicating mechanism. However, the actual corrections will be
smaller than these factors, since in an actual test the energy absorbed by
the specimen prevents the pendulum from making a full swing. Therefore,
the indicated breaking energy of the specimen must be included in the
calculation of the machine correction before determining the breaking
energy of the specimen (see 10.7). The A and B values also provide an
indication of the condition of the machine.
10.3.4 If excessive friction is indicated, the machine shall be
adjusted before starting a test. If the machine is equipped with
a digital energy indicating system, follow the manufacturer’s
instructions to correct for windage and friction. If excessive
friction is indicated, the machine shall be adjusted before
starting a test.
10.4 Check the specimens for conformity with the requirements of Sections 7, 8, and 10.1.
10.5 Measure the width and depth to the nearest 0.025 mm
(0.001 in.) after notching of each specimen. Measure the width
in the region of the notch. A micrometer or other measuring
device is necessary for measuring the depth. (See Fig. 6.)
10.6 Position the specimen precisely (see 6.7) so that it is
rigidly, but not too tightly (see Note 11), clamped in the vise.
Pay special attention to ensure that the “impacted end” of the
specimen as shown and dimensioned in Fig. 5 is the end
projecting above the vise. Release the pendulum and record the
excess energy remaining in the pendulum after breaking the
specimen, together with a description of the appearance of the
broken specimen (see failure categories in 5.8).
10.7 Subtract the windage and friction correction from the
10. Procedure
10.1 At least five and preferably ten or more individual
determinations of impact resistance must be made on each
sample to be tested under the conditions prescribed in Section
9. Each group shall consist of specimens with the same
nominal width (60.13 mm (60.005 in.)). In the case of
specimens cut from sheets that are suspected of being anisotropic, prepare and test specimens from each principal direction (lengthwise and crosswise to the direction of anisotropy).
10.2 Estimate the breaking energy for the specimen and
select a pendulum of suitable energy. Use the lightest standard
9
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(kJ/m 2 (ft·lbf/in.2)) may also need to be reported (see Appendix
X4), and
11.1.11 The percent of specimens failing in each category
suffixed by the corresponding letter code from 5.8.
indicated breaking energy of the specimen, unless determined
automatically by the indicating system (that is, digital display
or computer). If a mechanical dial and pointer is employed, use
the A and B factors and the appropriate tables or the graph
described in Annex A1 and Annex A2 to determine the
correction. For those digital systems that do not automatically
compensate for windage and friction, follow the manufacturer’s procedure for performing this correction.
10.7.1 In other words, either manually or automatically, the
windage and friction correction value is subtracted from the
uncorrected, indicated breaking energy to obtain the new
breaking energy. Compare the net value so found with the
energy requirement of the hammer specified in 10.2. If a
hammer of improper energy was used, discard the result and
make additional tests on new specimens with the proper
hammer. (See Annex A1 and Annex A2.)
10.8 Divide the net value found in 10.7 by the measured
width of the particular specimen to obtain the impact resistance
under the notch in J/m (ft·lbf/in.). If the optional units of kJ/m
2
2 (ft·lbf/in. ) are used, divide the net value found in 10.7 by the
measured width and depth under the notch of the particular
specimen to obtain the impact strength. The term, “depth under
the notch,” is graphically represented by Dimension A in Fig.
5. Consequently, the cross-sectional area (width times depth
under the notch) will need to be reported. (See Appendix X4.)
10.9 Calculate the average Izod impact resistance of the
group of specimens. However, only values of specimens
having the same nominal width and type of break may be
averaged. Values obtained from specimens that did not break in
the manner specified in 5.8 shall not be included in the average.
Also calculate the standard deviation of the group of values.
TEST METHOD C—CANTILEVER BEAM TEST FOR
MATERIALS OF LESS THAN 27 J/m (0.5 ft·lbf/in.)
12. Apparatus
12.1 The apparatus shall be the same as specified in Section
6.
13. Test Specimens
13.1 The test specimens shall be the same as specified in
Section 7.
14.1 Notching test specimens shall be the same as specified
in Section 8.
15. Conditioning
15.1 Specimen conditioning and test environment shall be
in accordance with Section 9.
16. Procedure
16.1 The procedure shall be the same as in Section 10 with
the addition of a procedure for estimating the energy to toss the
broken specimen part.
16.1.1 Make an estimate of the magnitude of the energy to
toss each different type of material and each different specimen
size (width). This is done by repositioning the free end of the
broken specimen on the clamped portion and striking it a
second time with the pendulum released in such a way as to
impart to the specimen approximately the same velocity it had
attained during the test. This is done by releasing the pendulum
from a height corresponding to that to which it rose following
the breakage of the test specimen. The energy to toss is then
considered to be the difference between the reading previously
described and the free swing reading obtained from this height.
A reproducible method of starting the pendulum from the
proper height must be devised.
11. Report
11.1.1 The test method used (Test Method A, C, D, or E),
11.1.2 Complete identification of the material tested, including type source, manufacturer’s code number, and previous
history,
11.1.3 A statement of how the specimens were prepared, the
testing conditions used, the number of hours the specimens
were conditioned after notching, and, for sheet materials, the
direction of testing with respect to anisotropy, if any,
11.1.4 The capacity of the pendulum in joules, or foot
pound-force, or inch pound-force,
11.1.5 The width and depth under the notch of each specimen tested,
11.1.6 The total number of specimens tested per sample of
material,
11.1.7 The type of failure (see 5.8),
11.1.8 The impact resistance must be reported in J/m
(ft·lbf/in.); the optional units of kJ/m2 (ft·lbf/in.2) may also be
required (see 10.8),
11.1.9 The number of those specimens that resulted in
failures which conforms to each of the requirement categories
in 5.8,
11.1.10 The average impact resistance and standard deviation (in J/m (ft·lbf/in.)) for those specimens in each failure
category, except non-break as presented in 5.8. Optional units
17. Report
17.1.1 Same as 11.1.1,
17.1.2 Same as 11.1.2,
17.1.3 Same as 11.1.3,
17.1.4 Same as 11.1.4,
17.1.5 Same as 11.1.5,
17.1.6 Same as 11.1.6,
17.1.7 The average reversed notch impact resistance, J/m
(ft·lbf/in.) (see 5.8 for failure categories),
17.1.8 Same as 11.1.8,
17.1.9 Same as 11.1.9,
17.1.10 Same as 11.1.10, and
17.1.11 Same as 11.1.11.
17.1.12 The estimated toss correction, expressed in terms of
joule (J) or foot pound-force (ft·lbf).
17.1.13 The difference between the Izod impact energy and
the toss correction energy is the net Izod energy. This value is
10
D 256
b 5 192.17 J/m 0.75 mm
5 256.23 J/m
of notch per mm of radius
divided by the specimen width (at the base of notch) to obtain
the net Izod impact resistance for the report.
TEST METHOD D—NOTCH RADIUS SENSITIVITY
TEST
24. Report
24.1.1 Same as 11.1.1,
24.1.2 Same as 11.1.2,
24.1.3 Same as 11.1.3,
24.1.4 Same as 11.1.4,
24.1.5 Same as 11.1.5,
24.1.6 Same as 11.1.6,
24.1.7 The average reversed notch impact resistance, in J/m
24.1.8 Same as 11.1.8,
24.1.9 Same as 11.1.9,
24.1.10 Same as 11.1.10, and
24.1.11 Same as 11.1.11.
24.1.12 Report the average value of b with its units, and the
average Izod impact resistance for a 0.25-mm (0.010-in.)
notch.
18. Apparatus
6.
19. Test Specimens
19.1 The test specimens shall be the same as specified in
Section 7. All specimens must be of the same nominal width,
preferably 6.4-mm (0.25-in.).
20.1 Notching shall be done as specified in Section 8 and
Fig. 5, except those ten specimens shall be notched with a
radius of 0.25 mm (0.010 in.) and ten specimens with a radius
of 1.0 mm (0.040 in.).
21. Conditioning
TEST METHOD E—CANTILEVER BEAM REVERSED
NOTCH TEST
25. Apparatus
6.
22. Procedure
22.1 Proceed in accordance with Section 10, testing ten
specimens of each notch radius.
22.2 The average impact resistance of each group shall be
calculated, except that within each group the type of break
must be homogeneously C, H, C and H, or P.
22.3 If the specimens with the 0.25-mm (0.010-in.) radius
notch do not break, the test is not applicable.
22.4 If any of ten specimens tested with the 1.0-mm
(0.040-in.) radius notch fail as in category NB, non-break, the
notch sensitivity procedure cannot be used without obtaining
additional data. A new set of specimens should be prepared
from the same sample, using a 0.50-mm (0.020-in.) notch
radius and the procedure of 22.1 and 22.2 repeated.
26. Test Specimens
26.1 The test specimen shall be the same as specified in
Section 7.
27.1 Notch the test specimens in accordance with Section 8.
28. Conditioning
29. Procedure
29.1 Proceed in accordance with Section 10, except clamp
the specimen so that the striker impacts it on the face opposite
the notch, hence subjecting the notch to compressive rather
than tensile stresses during impact (see Fig. 2 and Note 21,
Note 22, and Note 23).
23. Calculation
23.1 Calculate the slope of the line connecting the values for
impact resistance for 0.25 and 1.0-mm notch radii (or 0.010
and 0.040-in. notch radii) by the equation presented as follows.
(If a 0.500-mm (0.020-in.) notch radius is substituted, adjust
the calculation accordingly.)
NOTE 21—The reversed notch test employs a standard 0.25-mm (0.010in.) notch specimen to provide an indication of unnotched impact
resistance. Use of the reversed notch test obviates the need for machining
unnotched specimens to the required 10.2 6 0.05-mm (0.400 6 0.002-in.)
depth before testing and provides the same convenience of specimen
mounting as the standard notch tests (Test Methods A and C).
NOTE 22—Results obtained by the reversed notch test may not always
agree with those obtained on unnotched bars that have been machined to
the 10.2-mm (0.400-in.) depth requirement. For some materials, the
effects arising from the difference in the clamped masses of the two
specimen types during test, and those attributable to a possible difference
in toss energies ascribed to the broken ends of the respective specimens,
may contribute significantly to a disparity in test results.
NOTE 23—Where materials are suspected of anisotropy, due to molding
or other fabricating influences, notch reversed notch specimens on the face
opposite to that used for the standard Izod test; that is, present the same
face to the impact blow.
b 5 ~E2 2 E 1!/~R2 2 R1!
where:
E 2 = average impact resistance for the larger notch, J/m of
notch,
E1 = average impact resistance for the smaller notch, J/m
of notch,
R2 = radius of the larger notch, mm, and
R 1 = radius of the smaller notch, mm.
Example:
E1.0 5 330.95 J/m; E0.25 5 138.78 J/m
b 5 ~330.95 2 138.78 J/m!/~1.00 2 0.25 mm!
11
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30. Report
30.1.1 Same as 11.1.1,
30.1.2 Same as 11.1.2,
30.1.3 Same as 11.1.3,
30.1.4 Same as 11.1.4,
30.1.5 Same as 11.1.5,
30.1.6 Same as 11.1.6,
30.1.7 The average reversed notch impact resistance, J/m
30.1.8 Same as 11.1.8,
30.1.9 Same as 11.1.9,
30.1.10 Same as 11.1.10, and
30.1.11 Same as 11.1.11.
NOTE 24—Caution: The following explanations of Irand IR (see 31.331.3.3) are only intended to present a meaningful way of considering the
precision of this test method. The data in Tables 1-3 should not be
rigorously applied to acceptance or rejection of material, as those data are
specific to the round robin and may not be representative of other lots,
conditions, materials, or laboratories. Users of this test method should
apply the principles outlined in Practice E 691 to generate data specific to
their laboratory and materials, or between specific laboratories. The
principles of 31.3-31.3.3 would then be valid for such data.
31.3 Concept of Ir and IR—If Sr and SR have been calculated
from a large enough body of data, and for test results that were
averages from testing five specimens.
31.3.1 Repeatability, Ir (Comparing Two Test Results for the
Same Material, Obtained by the Same Operator Using the
Same Equipment on the Same Day)—The two test results
should be judged not equivalent if they differ by more than the
Ir value for that material.
31.3.2 Reproducibility, IR (Comparing Two Test Results for
the Same Material, Obtained by Different Operators Using
Different Equipment on Different Days)—The two test results
should be judged not equivalent if they differ by more than the
IR value for that material.
31.3.3 Any judgment in accordance with 31.3.1 and 31.3.2
would have an approximate 95 % (0.95) probability of being
correct.
31.4 Bias—There is no recognized standards by which to
estimate bias of these test methods.
31. Precision and Bias
31.1 Table 1 and Table 2 are based on a round robin10 in
accordance with Practice E 691. For each material, all the test
bars were prepared at one source, except for notching. Each
participating laboratory notched the bars that they tested. Table
1 and Table 2 are presented on the basis of a test result being
the average for five specimens. In the round robin each
laboratory tested, on average, nine specimens of each material.
31.2 Table 3 is based on a round robin8 involving five
materials tested by seven laboratories. For each material, all the
samples were prepared at one source, and the individual
specimens were all notched at the same laboratory. Table 3 is
presented on the basis of a test result being the average for five
specimens. In the round robin, each laboratory tested ten
specimens of each material. (See Note 24.)
NOTE 25—Numerous changes have occurred since the collection of the
original round-robin data in 1973.10 Consequently, a new task group has
been formed to evaluate a precision and bias statement for the latest
revision of these test methods.
32. Keywords
32.1 impact resistance; Izod impact; notch sensitivity;
notched specimen; reverse notch impact
10
Supporting data are available from ASTM Headquarters. Request RR: D201034.
TABLE 2 Precision Data, Test Method C—Reversed Notch Izod
Material
Phenolic
Average
SrA
SRB
IrC
IRD
0.45 (24.0)
0.038 (2.0)
0.129 (6.9)
0.10 (5.3)
0.36 (19.2)
A
B
C
Ir = 2.83 Sr.
D
IR = 2.83 SR.
12
Number of
Laboratories
15
D 256
TABLE 3 Precision Data, Test Method E—Reversed Notch Izod
Material
Acrylic sheet, unmodified
Premix molding compounds laminate
acrylic, injection molded
compound (SMC) laminate
Preformed mat laminate
SrA
Average
3.02 (161.3)
6.11 (326.3)
10.33 (551.6)
11.00 (587.4)
19.43 (1037.6)
0.243
0.767
0.878
0.719
0.960
(13.0)
(41.0)
(46.9)
(38.4)
(51.3)
SRB
0.525
0.786
1.276
0.785
1.618
(28.0)
(42.0)
(68.1)
(41.9)
(86.4)
IrC
IRD
0.68 (36.3)
2.17 (115.9)
2.49 (133.0)
2.03 (108.4)
2.72 (145.2)
0.71 (37.9)
2.22 (118.5)
3.61 (192.8)
2.22 (118.5)
4.58 (244.6)
A
Ir = 2.83 Sr.
D
IR = 2.83 SR.
B
C
ANNEXES
A1. INSTRUCTIONS FOR THE CONSTRUCTION OF A WINDAGE AND FRICTION CORRECTION CHART
A1.1 The construction and use of the chart herein described
is based upon the assumption that the friction and windage
losses are proportional to the angle through which these loss
torques are applied to the pendulum. Fig. A1.1 shows the
assumed energy loss versus the angle of the pendulum position
during the pendulum swing. The correction chart to be described is principally the left half of Fig. A1.1. The windage
and friction correction charts should be available from commercial testing machine manufacturers. The energy losses
designated as A and B are described in 10.3.
A1.2 Start the construction of the correction chart (see Fig.
A1.2) by laying off to some convenient linear scale on the
abscissa of a graph the angle of pendulum position for the
portion of the swing beyond the free hanging position. For
convenience, place the free hanging reference point on the
right end of the abscissa with the angular displacement
increasing linearly to the left. The abscissa is referred to as
Scale C. Although angular displacement is the quantity to be
represented linearly on the abscissa, this displacement is more
conveniently expressed in terms of indicated energy read from
the machine dial. This yields a nonlinear Scale C with indicated
pendulum energy increasing to the right.
FIG. A1.2 Sample Windage and Friction Correction Chart
starting with zero at the bottom and stopping at the maximum
expected pendulum friction and windage value at the top.
A1.3 On the right-hand ordinate lay off a linear Scale B
A1.4 On the left ordinate construct a linear Scale D ranging
from zero at the bottom to 1.2 times the maximum ordinate
value appearing on Scale B, but make the scale twice the scale
used in the construction of Scale B.
A1.5 Adjoining Scale D draw a curve OA that is the focus
of points whose coordinates have equal values of energy
correction on Scale D and indicated energy on Scale C. This
curve is referred to as Scale A and utilizes the same divisions
and numbering system as the adjoining Scale D.
A1.6 Instructions for Using Chart:
A1.6.1 Locate and mark on Scale A the reading A obtained
from the free swing of the pendulum with the pointer prepositioned in the free hanging or maximum indicated energy
position on the dial.
FIG. A1.1 Method of Construction of a Windage and Friction
Correction Chart
13
D 256
A1.6.2 Locate and mark on Scale B the reading B obtained
after several free swings with the pointer pushed up close to the
zero indicated energy position of the dial by the pendulum in
accordance with instructions in 10.3.
A1.6.3 Connect the two points thus obtained by a straight
line.
A1.6.4 From the indicated impact energy on Scale C project
up to the constructed line and across to the left to obtain the
correction for windage and friction from Scale D.
A1.6.5 Subtract this correction from the indicated impact
reading to obtain the energy delivered to the specimen.
A2. PROCEDURE FOR THE CALCULATION OF WINDAGE AND FRICTION CORRECTION
A2.1 The procedure for the calculation of the windage and
friction correction in this annex is based on the equations
developed by derivation in Appendix X3. This procedure can
be used as a substitute for the graphical procedure described in
Annex A1 and is applicable to small electronic calculator and
computer analysis.
hM
b max
A2.7 Measure specimen breaking energy, Es, J (ft·lbf).
A2.2 Calculate L, the distance from the axis of support to
the center of percussion as indicated in 6.3. (It is assumed here
that the center of percussion is approximately the same as the
center of gravity.)
A2.8 Calculate b for specimen measurement Es as:
b 5 cos 21 $1 2 @~hM/L!~1 2 E s/EM!#%
where:
b = angle pendulum travels for a given specimen, and
Es = dial reading breaking energy for a specimen, J (ft·lbf).
A2.3 Measure the maximum height, hM, of the center of
percussion (center of gravity) of the pendulum at the start of
the test as indicated in X2.16.
A2.4 Measure and record the energy correction, EA, for
windage of the pendulum plus friction in the dial, as determined with the first swing of the pendulum with no specimen
in the testing device. This correction must be read on the
energy scale, EM, appropriate for the pendulum used.
A2.9 Calculate total correction energy, ETC, as:
ETC 5 ~EA 2 ~E B/ 2!!~b/bmax! 1 ~E B/2!
where:
ETC = total correction energy for the breaking energy, Es,
of a specimen, J (ft·lbf), and
= energy correction for windage of the pendulum, J
EB
(ft·lbf).
A2.5 Without resetting the position of the indicator obtained in A2.4, measure the energy correction, EB , for
pendulum windage after two additional releases of the pendulum with no specimen in the testing device.
A2.6 Calculate b
max
bmax 5 cos
21
= maximum height of center of gravity of pendulum
at start of test, m (ft), and
= maximum angle pendulum will travel with one
swing of the pendulum.
as follows:
A2.10 Calculate the impact resistance using the following
formula:
$1 2 @~hM/L!~1 2 E A/EM!#%
Is 5 ~Es 2 E TC!/t
where:
= energy correction for windage of pendulum plus
EA
friction in dial, J (ft·lbf),
= full-scale reading for pendulum used, J (ft·lbf),
EM
L
= distance from fulcrum to center of gravity of
pendulum, m (ft),
where:
Is = impact resistance of specimen, J/m (ft·lbf/in.) of width,
and
t = width of specimen or width of notch, m (in.).
14
D 256
APPENDIXES
(Nonmandatory Information)
X1. PROCEDURE FOR THE INSPECTION AND VERIFICATION OF NOTCH
X1.1 The purpose of this procedure is to describe the
microscopic method to be used for determining the radius and
angle of the notch. These measurements could also be made
using a comparator if available.
NOTE X1.1—The notch shall have a radius of 0.25 6 0.05 mm (0.010
6 0.002 in.) and an angle of 45 6 1°.
X1.2 Apparatus:
X1.2.1 Optical Device with minimum magnification of
603, Filar glass scale and camera attachment.
X1.2.2 Transparent Template, (will be developed in this
procedure).
X1.2.3 Ruler.
X1.2.4 Compass.
X1.2.5 Plastic 45°–45°–90° Drafting Set Squares (Triangles).
X1.3 A transparent template must be developed for each
magnification and for each microscope used. It is preferable
that each laboratory standardize on one microscope and one
magnification. It is not necessary for each laboratory to use the
same magnification because each microscope and camera
combination has somewhat different blowup ratios.
X1.3.1 Set the magnification of the optical device at a
suitable magnification with a minimum magnification of 603.
X1.3.2 Place the Filar glass slide on the microscope platform. Focus the microscope so the most distinct image of the
Filar scale is visible.
X1.3.3 Take a photograph of the Filar scale (see Fig. X1.1).
X1.3.4 Create a template similar to that shown in Fig. X1.2.
X1.3.4.1 Find the approximate center of the piece of paper.
X1.3.4.2 Draw a set of perpendicular coordinates through
the center point.
X1.3.4.3 Draw a family of concentric circles that are spaced
according to the dimensions of the Filar scale.
NOTE 1—Magnification = 100X.
FIG. X1.2 Example of Transparent Template for Determining
Radius of Notch
X1.3.4.4 This is accomplished by first setting a mechanical
compass at a distance of 0.1 mm (0.004 in.) as referenced by
the magnified photograph of the Filar eyepiece. Subsequent
circles shall be spaced 0.02 mm apart (0.001 in.), as rings with
the outer ring being 0.4 mm (0.016 in.) form the center.
X1.3.5 Photocopy the paper with the concentric circles to
make a transparent template of the concentric circles.
X1.3.6 Construct Fig. X1.3 by taking a second piece of
paper and find it’s approximate center and mark this point.
Draw one line through this center point. Label this line zero
degree (0°). Draw a second line perpendicular to the first line
through this center point. Label this line “90°.” From the center
draw a line that is 44 degrees relative to the “0°.” Label the line
“44°.” Draw another line at 46°. Label the line “46°.”
X1.4 Place a microscope glass slide on the microscope
platform. Place the notched specimen on top of the slide. Focus
the microscope. Move the specimen around using the platform
adjusting knobs until the specimen’s notch is centered and near
the bottom of the viewing area. Take a picture of the notch.
X1.4.1 Determination of Notching Radius (see Fig. X1.4):
X1.4.1.1 Place the picture on a sheet of paper. Position the
picture so that bottom of the notch in the picture faces
downwards and is about 64 mm (2.5 in.) from the bottom of the
NOTE 1—100X reference.
NOTE 2—0.1 mm major scale; 0.01 mm minor scale.
FIG. X1.1 Filar Scale
15
D 256
FIG. X1.3 Example of Transparent Template for Determining
Angle of Notch
FIG. X1.4 Determination of Notching Radius
X1.4.2.1 Place transparent template for determining notch
angle (see Fig. X1.3) on top of the photograph attached to the
sheet of paper. Rotate the picture so that the notch tip is pointed
towards you. Position the center point of the template on top of
Point I established in 0° axis of the template with the right side
straight portion of the notch. Check the left side straight
portion of the notch to ensure that this portion falls between the
44 and 46° degree lines. If not, replace the blade.
paper. Tape the picture down to the paper.
X1.4.1.2 Draw two lines along the sides of the notch
projecting down to a point where they intersect below Notch
Point I (see Fig. X1.4).
X1.4.1.3 Open the compass to about 51 mm (2 in.). Using
Point I as a reference, draw two arcs intersecting both sides of
the notch (see Fig. X1.4). These intersections are called 1a and
1b.
X1.4.1.4 Close the compass to about 38 mm (1.5 in.). Using
Point 1a as the reference point draw an arc (2a) above the
notch, draw a second arc (2b) that intersects with arc 2a at
Point J. Draw a line between I and J. This establishes the
centerline of the notch (see Fig. X1.4).
X1.4.1.5 Place the transparent template on top of the picture
and align the center of the concentric circles with the drawn
centerline of the notch (see Fig. X1.4).
X1.4.1.6 Slide the template down the centerline of the notch
until one concentric circle touches both sides of the notch.
Record the radius of the notch and compare it against the
ASTM limits of 0.2 to 0.3 mm (0.008 to 0.012 in.).
X1.4.1.7 Examine the notch to ensure that there are no flat
spots along the measured radius.
X1.4.2 Determination of Notch Angle:
X1.5 A picture of a notch shall be taken at least every 500
notches or if a control sample gives a value outside its
three-sigma limits for that test.
X1.6 If the notch in the control specimen is not within the
requirements, a picture of the notching blade should be taken
and analyzed by the same procedure used for the specimen
notch. If the notching blade does not meet ASTM requirements
or shows damage, it should be replaced with a new blade which
has been checked for proper dimensions.
X1.7 It is possible that the notching cutter may have the
correct dimensions but does not cut the correct notch in the
specimen. If that occurs it will be necessary to evaluate other
conditions (cutter and feed speeds) to obtain the correct notch
dimension for that material.
16
D 256
X2. CALIBRATION OF PENDULUM-TYPE HAMMER IMPACT MACHINES FOR USE WITH PLASTIC
SPECIMENS
edge should make contact across the entire width of the bar. If
only partial contact is made, examine the vise and pendulum
for the cause. If the cause is apparent, make the appropriate
correction. If no cause is apparent, remove the striker and shim
up or grind its back face to realign the striking edge with the
surface of the bar.
X2.1 This calibration procedure applies specifically to the
Izod impact machine. However, much of this procedure can be
applied to the Charpy impact machine as well.
X2.2 Locate the impact machine on a sturdy base. It shall
not “walk” on the base and the base shall not vibrate appreciably. Loss of energy from vibrations will give high readings.
It is recommended that the impact tester be bolted to a base
having a mass of at least 23 kg if it is used at capacities higher
than 2.7 J (2 ft·lbf).
X2.10 Check the oil line on the face of the bar for
horizontal setting of striking edge within tan−1 0.002 with a
machinist’s square.
X2.11 Without taking the bar of X2.8 from the vise of the
machine, scratch a thin line at the top edge of the vise on the
face opposite the striking face of the bar. Remove the bar from
the vise and transfer this line to the striking face, using a
machinist’s square. The distance from the striking oil line to
the top edge of the vise should be 22 6 0.05 mm (0.87 6 0.002
in.). Correct with shims or grinding, as necessary, at the bottom
of the vise.
X2.3 Check the level of the machine in both directions in
the plane of the base with spirit levels mounted in the base, by
a machinist’s level if a satisfactory reference surface is
available, or with a plumb bob. The machine should be made
level to within tan−1 0.001 in the plane of swing and to within
tan −1 0.002 in the plane perpendicular to the swing.
X2.4 With a straightedge and a feeler gage or a depth gage,
check the height of the movable vise jaw relative to the fixed
vise jaw. It must match the height of the fixed vise jaw within
0.08 mm (0.003 in.).
X2.12 When the pendulum is hanging free in its lowest
position, the energy reading must be within 0.2 % of full scale.
X2.13 Insert the bar of X2.8 into the vise and clamp it
tightly in a vertical position. When the striking edge is held in
contact with the bar, the energy reading must be within 0.2 %
of full scale.
X2.5 Contact the machine manufacturer for a procedure to
ensure the striker radius is in tolerance (0.80 6 0.20 mm) (see
6.3).
X2.6 Check the transverse location of the center of the
pendulum striking edge that shall be within 0.40 mm (0.016
in.) of the center of the vise. Readjust the shaft bearings or
relocate the vise, or straighten the pendulum shaft as necessary
to attain the proper relationship between the two centers.
X2.14 Swing the pendulum to a horizontal position and
support it by the striking edge in this position with a vertical
bar. Allow the other end of this bar to rest at the center of a load
pan on a balanced scale. Subtract the weight of the bar from the
total weight to find the effective weight of the pendulum. The
effective pendulum weight should be within 0.4 % of the
required weight for that pendulum capacity. If weight must be
added or removed, take care to balance the added or removed
weight without affecting the center of percussion relative to the
striking edge. It is not advisable to add weight to the opposite
side of the bearing axis from the striking edge to decrease the
effective weight of the pendulum since the distributed mass can
lead to large energy losses from vibration of the pendulum.
X2.7 Check the pendulum arm for straightness within 1.2
mm (0.05 in.) with a straightedge or by sighting down the
shaft. Allowing the pendulum to slam against the catch
sometimes bends the arm especially when high-capacity
weights are on the pendulum.
X2.8 Insert vertically and center with a locating jig and
clamp in the vise a notched machined metal bar 12.7-mm
(0.500-in.) square, having opposite sides parallel within 0.025
mm (0.001 in.) and a length of 60 mm (2.4 in.). Check the bar
for vertical alignment within tan−1 0.005 in both directions
with a small machinist’s level. Shim up the vise, if necessary,
to correct for errors in the plane of pendulum swing, using care
to preserve solid support for the vise. For errors in the plane
perpendicular to the plane of pendulum swing, machine the
inside face of the clamp-type locating jig for correct alignment
if this type of jig is used. If a blade-type jig is used, use shims
or grind the base of the vise to bring the top surface level.
X2.15 Calculate the effective length of the pendulum arm,
or the distance to the center of percussion from the axis of
rotation, by the procedure in Note 9. The effective length must
be within the tolerance stated in 6.3.
X2.16 Measure the vertical distance of fall of the pendulum
striking edge from its latched height to its lowest point. This
distance should be 610 6 2.0 mm (24 6 0.1 in.). This
measurement may be made by blocking up a level on the top
of the vise and measuring the vertical distance from the striking
edge to the bottom of the level (top of vise) and subtracting
22.0 mm (0.9 in.). The vertical falling distance may be adjusted
by varying the position of the pendulum latch.
X2.9 Insert and clamp the bar described in X2.8 in a
vertical position in the center of the vise so that the notch in the
bar is slightly below the top edge of the vise. Place a thin film
of oil on the striking edge of the pendulum with an oiled tissue
and let the striking edge rest gently against the bar. The striking
X2.17 Notch a standard specimen on one side, parallel to
the molding pressure, at 32 mm (1.25 in.) from one end. The
17
D 256
the horizontal and vertical directions within 0.025 mm (0.001
in.). Inserting the machined square metal bar of X2.7 into the
vise in a vertical position and clamping until the jaws begin to
bind may check parallelism. Any freedom between the metal
bar and the clamping surfaces of the jaws of the vise must not
exceed the specified tolerance.
depth of the plastic material remaining in the specimen under
the notch shall be 10.16 6 0.05 mm (0.400 6 0.002 in.). Use
a jig to position the specimen correctly in the vise. When the
specimen is clamped in place, the center of the notch should be
within 0.12 mm (0.005 in.) of being in line with the top of the
fixed surface of the vise and the specimen should be centered
midway within 0.40 mm (0.016 in.) between the sides of the
clamping faces. The notched face should be the striking face of
the specimen for the Izod test. Under no circumstances during
the breaking of the specimen should the top of the specimen
touch the pendulum except at the striking edge.
X2.23 The top edges of the fixed and moveable jaws of the
vise shall have a radius of 0.25 6 0.12 mm (0.010 6 0.005 in.).
Depending upon whether Test Method A, C, D, or E is used, a
stress concentration may be produced as the specimen breaks.
Consequently, the top edge of the fixed and moveable jaw
needs to be carefully examined.
X2.18 If a clamping-type locating jig is used, examine the
clamping screw in the locating jig. If the thread has a loose fit
the specimen may not be correctly positioned and may tend to
creep as the screw is tightened. A burred or bent point on the
screw may also have the same effect.
X2.24 If a brittle unfilled or granular-filled plastic bar such
as a general-purpose wood-flour-filled phenolic material is
available, notch and break a set of bars in accordance with
these test methods. Examine the surface of the break of each
bar in the vise. If the break is flat and smooth across the top
surface of the vise, the condition of the machine is excellent.
Considerable information regarding the condition of an impact
machine can be obtained by examining the broken sections of
specimens. No weights should be added to the pendulum for
the preceding tests.
X2.19 If a pointer and dial mechanism is used to indicate
the energy, the pointer friction should be adjusted so that the
pointer will just maintain its position anywhere on the scale.
The striking pin of the pointer should be securely fastened to
the pointer. Friction washers with glazed surfaces should be
replaced with new washers. Friction washers should be on
either side of the pointer collar. A heavy metal washer should
back the last friction washer installed. Pressure on this metal
washer is produced by a thin-bent, spring washer and locknuts.
If the spring washer is placed next to the fiber friction washer
the pointer will tend to vibrate during impact.
X2.25 The machine should not be used to indicate more
than 85 % of the energy capacity of the pendulum. Extra
weight added to the pendulum will increase available energy of
the machine. This weight must be added so as to maintain the
center of percussion within the tolerance stated in 6.3. Correct
effective weight for any range can be calculated as follows:
X2.20 The free-swing reading of the pendulum (without
specimen) from the latched height should be less than 2.5 % of
pendulum capacity on the first swing. If the reading is higher
than this, then the friction in the indicating mechanism is
excessive or the bearings are dirty. To clean the bearings, dip
them in grease solvent and spin-dry in an air jet. Clean the
bearings until they spin freely, or replace them. Oil very lightly
with instrument oil before replacing. A reproducible method of
starting the pendulum from the proper height must be devised.
W 5 Ep/h
where:
W = effective pendulum weight, N (lbf) (see X2.13),
Ep = potential or available energy of the machine, J (ft·lbf),
and
h = vertical distance of fall of the pendulum striking
edge, m (ft) (see X2.16).
X2.21 The shaft about which the pendulum rotates shall
have no detectable radial play (less than 0.05 mm (0.002 in.)).
An endplay of 0.25 mm (0.010 in.) is permissible when a 9.8-N
(2.2-lbf) axial force is applied in alternate directions.
Each 4.5 N (1 lbf) of added effective weight increases the
capacity of the machine by 2.7 J (2 ft·lbf).
NOTE X2.1—If the pendulum is designed for use with add-on weight, it
is recommended that it be obtained through the equipment manufacturer.
X2.22 The clamping faces of the vise should be parallel in
X3. DERIVATION OF PENDULUM IMPACT CORRECTION EQUATIONS
E M 5 hMWpg
X3.1 From right triangle distances in Fig. X3.1:
L 2 h 5 L cos b
(X3.1)
X3.5 The potential energy gained by the pendulum, Ep, is
related to the absorption of energy of a specimen, E s, by the
following equation:
X3.2 But the potential energy gain of pendulum Ep is:
Ep 5 hW pg
(X3.2)
EM 2 E s 5 E p
X3.3 Combining Eq X3.1 and Eq X3.2 gives the following:
L 2 Ep/Wpg 5 L cos b
(X3.4)
X3.6
(X3.3)
Combining Eq X3.3-X3.5 gives the following:
~EM 2 E s!/EM 5 L/hM ~1 2 cos b!
X3.4 The maximum energy of the pendulum is the potential
energy at the start of the test, EM, or
X3.7 Solving Eq X3.6 for b gives the following:
18
(X3.5)
(X3.6)
D 256
EB/2 5 m~0! 1 b
(X3.9)
b 5 EB/2
(X3.10)
or:
X3.10 The energy correction, EA, on the first swing of the
pendulum occurs at the maximum pendulum angle, bmax.
Substituting in Eq X3.8 gives the following:
E A 5 mbmax 1 ~EB/2!
(X3.11)
X3.11 Combining Eq X3.8 and Eq X3.11 gives the following:
ETC 5 ~EA 2 ~E B/2!!~b/bmax! 1 ~E B/2!
X3.12 Nomenclature:
FIG. X3.1 Swing of Pendulum from Its Rest Position
(X3.7)
b
EA
X3.8 From Fig. X3.2, the total energy correction ETC is
given as:
EB
EM
b 5 cos21$1 2 @~h M/L!~1 2 Es/EM!#%
ETC 5 mb 1 b
X3.9
energy:
(X3.8)
Ep
But at the zero point of the pendulum potential
Es
ETC
g
h
hM
m
L
Wp
b
FIG. X3.2 Total Energy Correction for Pendulum Windage and
Dial Friction as a Function of Pendulum Position
= intercept of total correction energy straight line,
= energy correction, including both pendulum windage plus dial friction, J,
= energy correction for pendulum windage only, J,
= maximum energy of the pendulum (at the start of
test), J,
= potential energy gain of pendulum from the pendulum rest position, J,
= uncorrected breaking energy of specimen, J,
= total energy correction for a given breaking energy,
E s, J,
= acceleration of gravity, m/s2,
= distance center of gravity of pendulum rises vertically from the rest position of the pendulum, m,
= maximum height of the center of gravity of the
pendulum, m,
= slope of total correction energy straight line,
= distance from fulcrum to center of gravity of pendulum, m,
= weight of pendulum, as determined in X2.13, kg,
and
= angle of pendulum position from the pendulum rest
position.
X4. UNIT CONVERSIONS
X4.1 Joules per metre (J/m) cannot be converted directly
into kJ/m2. Note that the optional units of kJ/m2 (ft·lbf/in.2)
may also be required; therefore, the cross-sectional area under
the notch must be reported.
1 ft·lbf/in.
1 ft·lbf/in.
1 ft·lbf/in.
= (39.37)(1.356) J/m
= 53.4 J/m
= 0.0534 kJ/m
X4.2.2 Example 2:
1
1
1
1
X4.2 The following examples are approximations:
X4.2.1 Example 1:
1 ft·lbf/39.37 in.
(X3.12)
= 1.356 J/m
19
ft·lbf/1550 in.2
ft·lbf/in.2
ft·lbf/in.2
ft·lbf/in.2
= 1.356 J/m2
= (1550)(1.356) J/m2
= 2101 J/m2
= 2.1 kJ/m2
D 256
SUMMARY OF CHANGES
This section identifies the location of selected changes to these test methods. For the convenience of the user,
Committee D20 has highlighted those changes that may impact the use of this test method. This section may also
include descriptions of the changes or reasons for the changes, or both.
D 256 – 97:
(1) Test Method B (Charpy) has been removed from these test
methods. This test method is being developed as a separate
standard. Research Report D20-1034 will be moved to the new
charpy standard.
(2) The designations for Test Methods A, C, D, or E remain
unchanged due to potential problems with historical data.
(3) These test methods have been extensively revised, edito-
rially and technically, with major emphasis on tolerances and
units.
D 256 – 00:
(1) Notch depth dimensions in 8.4, Fig. 5, and X2.17 changed
to 10.16 6 0.05 mm.
(2) Note 8 added.
(3) Deleted former Appendix X4 on Determination of Clamping Load on Izod Specimens.
(www.astm.org).
20
Standard Test Method for
Water Absorption of Plastics1
tics can be made on the basis of values obtained in accordance
with 7.1 and 7.4.
3.3 Ideal diffusion of liquids4 into polymers is a function of
the square root of immersion time. Time to saturation is
strongly dependent on specimen thickness. For example, Table
1 shows the time to approximate time saturation for various
thickness of nylon-6.
3.4 The moisture content of a plastic is very intimately
related to such properties as electrical insulation resistance,
dielectric losses, mechanical strength, appearance, and dimensions. The effect upon these properties of change in moisture
content due to water absorption depends largely on the type of
exposure (by immersion in water or by exposure to high
humidity), shape of the part, and inherent properties of the
plastic. With nonhomogeneous materials, such as laminated
forms, the rate of water absorption may be widely different
through each edge and surface. Even for otherwise homogeneous materials, it may be slightly greater through cut edges
than through molded surfaces. Consequently, attempts to
correlate water absorption with the surface area must generally
be limited to closely related materials and to similarly shaped
specimens: For materials of widely varying density, relation
between water-absorption values on a volume as well as a
weight basis may need to be considered.
1. Scope
1.1 This test method covers the determination of the relative
rate of absorption of water by plastics when immersed. This
test method is intended to apply to the testing of all types of
plastics, including cast, hot-molded, and cold-molded resinous
products, and both homogeneous and laminated plastics in rod
and tube form and in sheets 0.13 mm (0.005 in.) or greater in
thickness.
1.2 The values given in SI units are to be regarded as the
standard. The values stated in parentheses are for information
only.
NOTE 1—ISO 62 is technically equivalent to this test method.
2.1 ASTM Standards:
D 647 Practice for Design of Molds for Test Specimens of
Plastic Molding Materials2
2.2 ISO Standard:
ISO 62 Plastics—Determination of Water Absorption3
4. Apparatus
4.1 Balance—An analytical balance capable of reading
0.0001 g.
4.2 Oven, capable of maintaining uniform temperatures of
50 6 3°C (122 6 5.4°F) and of 105 to 110°C (221 to 230°F).
3.1 This test method for rate of water absorption has two
chief functions: first, as a guide to the proportion of water
absorbed by a material and consequently, in those cases where
the relationships between moisture and electrical or mechanical
properties, dimensions, or appearance have been determined,
as a guide to the effects of exposure to water or humid
conditions on such properties; and second, as a control test on
the uniformity of a product. This second function is particularly applicable to sheet, rod, and tube arms when the test is
made on the finished product.
3.2 Comparison of water absorption values of various plas-
5. Test Specimen
5.1 The test specimen for molded plastics shall be in the
form of a disk 50.8 mm (2 in.) in diameter and 3.2 mm (1⁄8 in.)
in thickness (see Note 2). Permissible variations in thickness
are 60.18 mm (60.007 in.) for hot-molded and 60.30 mm
(60.012 in.) for cold-molded or cast materials.
NOTE 2—The disk mold prescribed in the Molds for Disk Test
Specimens Section of Practice D 647 is suitable for molding disk test
1
This test method is under the jurisdiction of ASTM Committee D-20 on Plastics
and is the direct responsibility of Subcommittee D 20.50 on Permanence Properties.
Current edition approved July 10, 1998. Published January 1999. Originally
published as D 570 – 40 T. Last previous edition D 570 – 95.
2
Discontinued 1994; replaced by D 1896, D 3419, D 3641, D 4703, and D 5227.
See 1994 Annual Book of ASTM Standards, Vol 08.01.
3
Available from American National Standards Institute, 11 W. 42nd St., 13th
4
Additional information regarding diffusion of liquids in polymers can be found
in the following references: (1) Diffusion, Mass Transfer in Fluid Systems, E. L.
Cussler, Cambridge University Press, 1985, ISBN 0-521-29846-6, (2) Diffusion in
Polymers, J. Crank and G. S. Park, Academic Press, 1968, and (3) “Permeation,
Diffusion, and Sorption of Gases and Vapors,” R. M. Felder and G. S. Huvard, in
Methods of Experimental Physics, Vol 16C, 1980, Academic Press.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
1
D 570
at 50 6 3°C (122 6 5.4°F), cooled in a desiccator, and immediately weighed to the nearest 0.001 g.
TABLE 1 Time to Saturation for Various Thickness of Nylon-6
Thickness, mm
Typical Time to 95 % Saturation, h
1
2
3.2
10
25
100
400
1 000
10 000
62 000
NOTE 4—If a static charge interferes with the weighing, lightly rub the
surface of the specimens with a grounded conductor.
6.1.2 Specimens of materials, such as phenolic laminated
plastics and other products whose water-absorption value has
been shown not to be appreciably affected by temperatures up
to 110°C (230°F), shall be dried in an oven for 1 h at 105 to
110°C (221 to 230°F).
6.1.3 When data for comparison with absorption values for
other plastics are desired, the specimens shall be dried in an
oven for 24 h at 50 6 3°C (122 6 5.4°F), cooled in a desiccator, and immediately weighed to the nearest 0.001 g.
specimens of thermosetting materials but not thermoplastic materials.
5.2 ISO Standard Specimen—The test specimen for homogeneous plastics shall be 60 by 60 by 1 mm. Tolerance for the
60-mm dimension is 62 mm and 60.05 mm for the 1-mm
thickness. This test method and ISO 62 are technically equivalent when the test specimen described in 5.2 is used.
5.3 The test specimen for sheets shall be in the form of a bar
76.2 mm (3 in.) long by 25.4 mm (1 in.) wide by the thickness
of the material. When comparison of absorption values with
molded plastics is desired, specimens 3.2 mm (1⁄8 in.) thick
should be used. Permissible variations in thickness shall be
0.20 mm (60.008 in.) except for asbestos-fabric-base phenolic
laminated materials or other materials which have greater
standard commercial tolerances.
5.4 The test specimen for rods shall be 25.4 mm (1 in.) long
for rods 25.4 mm in diameter or under and 12.7 mm (1⁄2 in.)
long for larger-diameter rods. The diameter of the specimen
shall be the diameter of the finished rod.
5.5 The test specimen for tubes less than 76 mm (3 in.) in
inside diameter shall be the full section of the tube and 25.4
mm (1 in.) long. For tubes 76 mm (3 in.) or more in inside
diameter, a rectangular specimen shall be cut 76 mm in length
in the circumferential direction of the tube and 25.4 mm in
width lengthwise of the tube.
5.6 The test specimens for sheets, rods, and tubes shall be
machined, sawed, or sheared from the sample so as to have
smooth edges free from cracks. The cut edges shall be made
smooth by finishing with No. 0 or finer sandpaper or emery
cloth. Sawing, machining, and sandpapering operations shall
be slow enough so that the material is not heated appreciably.
7. Procedure
7.1 Twenty-Four Hour Immersion—The conditioned specimens shall be placed in a container of distilled water maintained at a temperature of 23 6 1°C (73.4 6 1.8°F), and shall
rest on edge and be entirely immersed. At the end of 24, +1⁄2,
−0 h, the specimens shall be removed from the water one at a
time, all surface water wiped off with a dry cloth, and weighed
to the nearest 0.001 g immediately. If the specimen is 1⁄16 in. or
less in thickness, it shall be put in a weighing bottle immediately after wiping and weighed in the bottle.
7.2 Two-Hour Immersion—For all thicknesses of materials
having a relatively high rate of absorption, and for thin
specimens of other materials which may show a significant
weight increase in 2 h, the specimens shall be tested as
described in 7.1 except that the time of immersion shall be
reduced to 120 6 4 min.
7.3 Repeated Immersion—A specimen may be weighed to
the nearest 0.001 g after 2-h immersion, replaced in the water,
and weighed again after 24 h.
NOTE 5—In using this test method the amount of water absorbed in 24
h may be less than it would have been had the immersion not been
interrupted.
7.4 Long-Term Immersion—To determine the total water
absorbed when substantially saturated, the conditioned specimens shall be tested as described in 7.1 except that at the end
of 24 h they shall be removed from the water, wiped free of
surface moisture with a dry cloth, weighed to the nearest 0.001
g immediately, and then replaced in the water. The weighings
shall be repeated at the end of the first week and every two
weeks thereafter until the increase in weight per two-week
period, as shown by three consecutive weighings, averages less
than 1 % of the total increase in weight or 5 mg, whichever is
greater; the specimen shall then be considered substantially
saturated. The difference between the substantially saturated
weight and the dry weight shall be considered as the water
absorbed when substantially saturated.
7.5 Two-Hour Boiling Water Immersion—The conditioned
specimens shall be placed in a container of boiling distilled
water, and shall be supported on edge and be entirely immersed. At the end of 120 6 4 min, the specimens shall be
removed from the water and cooled in distilled water maintained at room temperature. After 15 6 1 min, the specimens
shall be removed from the water, one at a time, all surface
water removed with a dry cloth, and the specimens weighed to
NOTE 3—If there is any oil on the surface of the specimen when
received or as a result of machining operations, wash the specimen with
a cloth wet with gasoline to remove oil, wipe with a dry cloth, and allow
to stand in air for 2 h to permit evaporation of the gasoline. If gasoline
attacks the plastic, use some suitable solvent or detergent that will
evaporate within the 2-h period.
5.7 The dimensions listed in the following table for the
various specimens shall be measured to the nearest 0.025 mm
(0.001 in.). Dimensions not listed shall be measured within 0.8
mm (61⁄32 in.).
Type of
Specimen
Molded disk
Sheet
Rod
Tube
Dimensions to Be Measured to the
Nearest 0.025 mm (0.001 in.)
thickness
thickness
length and diameter
inside and outside diameter, and wall thickness
6. Conditioning
6.1 Three specimens shall be conditioned as follows:
6.1.1 Specimens of materials whose water-absorption value
would be appreciably affected by temperatures in the neighborhood of 110°C (230°F), shall be dried in an oven for 24 h
2
D 570
Soluble matter lost, % 5
conditioned weight 2 reconditioned weight
3 100
conditioned weight
the nearest 0.001 g immediately. If the specimen is 1⁄16 in. or
less in thickness, it shall be weighed in a weighing bottle.
7.6 One-Half-Hour Boiling Water Immersion—For all
thicknesses of materials having a relatively high rate of
absorption and for thin specimens of other materials which
may show a significant weight increase in 1⁄2 h, the specimens
shall be tested as described in 7.5, except that the time of
immersion shall be reduced to 30 6 1 min.
7.7 Immersion at 50°C—The conditioned specimens shall
be tested as described in 7.5, except that the time and
temperature of immersion shall be 48 6 1 h and 50 6 1°C
(122.0 6 1.8°F), respectively, and cooling in water before
weighing shall be omitted.
7.8 When data for comparison with absorption values for
other plastics are desired, the 24-h immersion procedure
described in 7.1 and the equilibrium value determined in 7.4
shall be used.
NOTE 6—When the weight on reconditioning the specimen after immersion in water exceeds the conditioned weight prior to immersion,
report “none” under 9.1.6.
9.1.7 For long-term immersion procedure only, prepare a
graph of the increase in weight as a function of the square root
of each immersion time. The initial slope of this graph is
proportional to the diffusion constant of water in the plastic.
The plateau region with little or no change in weight as a
function of the square root of immersion time represents the
saturation water content of the plastic.
NOTE 7—Deviation from the initial slope and plateau model indicates
that simple diffusion may be a poor model for determining water content.
In such cases, additional studies are suggested to determine a better model
for water absorption.
8. Reconditioning
8.1 When materials are known or suspected to contain any
appreciable amount of water-soluble ingredients, the specimens, after immersion, shall be weighed, and then reconditioned for the same time and temperature as used in the original
drying period. They shall then be cooled in a desiccator and
immediately reweighed. If the reconditioned weight is lower
than the conditioned weight, the difference shall be considered
as water-soluble matter lost during the immersion test. For such
materials, the water-absorption value shall be taken as the sum
of the increase in weight on immersion and of the weight of the
water-soluble matter.
9.1.8 The percentage of water absorbed, which is the sum of
the values in 9.1.5 and 9.1.6, and
9.1.9 Any observations as to warping, cracking, or change
in appearance of the specimens.
10. Precision and Bias
10.1 Precision—An interlaboratory test program was carried out using the procedure outlined in 7.1, involving three
laboratories and three materials. Analysis of this data yields the
following coefficients of variation (average of three replicates).
9. Calculation and Report
9.1 The report shall include the values for each specimen
and the average for the three specimens as follows:
9.1.1 Dimensions of the specimens before test, measured in
accordance with 5.6, and reported to the nearest 0.025 mm
(0.001 in.),
9.1.2 Conditioning time and temperature,
9.1.3 Immersion procedure used,
9.1.4 Time of immersion (long-term immersion procedure
only),
9.1.5 Percentage increase in weight during immersion, calculated to the nearest 0.01 % as follows:
Increase in weight, % 5
5
Average absorption above
1 % (2 materials)
Average absorption below
0.2 % (1 material)
Within
Laboratories
2.33 %
Between
Laboratories
4.89 %
9.01 %
16.63 %
NOTE 8—A round robin is currently under way to more completely
determine repeatability and reproducibility of this test method.
10.2 Bias—No justifiable statement on the bias of this test
method can be made, since the true value of the property
cannot be established by an accepted referee method.
11. Keywords
11.1 absorption; immersion; plastics; water
wet weight 2 conditioned weight
3100
conditioned weight
9.1.6 Percentage of soluble matter lost during immersion, if
determined, calculated to the nearest 0.01 % as follows (see
Note 6):
5
Supporting data are available from ASTM Headquarters. Request RR: D-201064.
The American Society for Testing and Materials takes no position respecting the validity of any patent rights asserted in connection
with any item mentioned in this standard. Users of this standard are expressly advised that determination of the validity of any such
patent rights, and the risk of infringement of such rights, are entirely their own responsibility.
and should be addressed to ASTM Headquarters. Your comments will receive careful consideration at a meeting of the responsible
technical committee, which you may attend. If you feel that your comments have not received a fair hearing you should make your
views known to the ASTM Committee on Standards, at the address shown below.
This standard is copyrighted by ASTM, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the above address or at
610-832-9585 (phone), 610-832-9555 (fax), or service@astm.org (e-mail); or through the ASTM website (www.astm.org).
3
LAMPIRAN 2
Tabel.2.1.Data Pengujian Bending Alkali 2 jam
Jenis
No
Lebar
Tebal
(mm)
Panjang
Awal
(mm)
komposit
Spesimen
(mm)
Volume
B/T1-20/1
20%
Luas
(mm )
12
1.35
66
792
B/T1-20/2
13.05
1.35
66
861.3
B/T1-20/3
12.6
1.35
69
869.4
Volume
B/T1-30/1
11.95
1.55
68
812.6
30%
B/T1-30/2
12.95
1.8
69
893.55
B/T1-30/3
12.75
1.7
68
867
Volume
B/T1-40/1
12.7
2.3
67
850.9
40%
B/T1-40/2
12.95
2.25
67
867.65
B/T1-40/3
13.3
2.3
68
904.4
Volume
B/T1-50/1
13.65
1.9
68
928.2
50%
B/T1-50/2
13.05
1.95
68
887.4
B/T1-50/3
12.9
1.9
67
864.3
2
Tebal 2 mm
Jenis
No
Lebar
Tebal
(mm)
Panjang
Awal
(mm)
komposit
Spesimen
(mm)
Volume
B/T2-20/1
20%
(mm )
12.45
2.1
86
1070.7
B/T2-20/2
12.75
2.1
86
1096.5
B/T2-20/3
B/T2-30/1
B/T2-30/2
B/T2-30/3
B/T2-40/1
B/T2-40/2
12.5
12.7
13.3
12.95
12.55
13.15
2.15
2.8
2.85
2.8
2.75
2.75
86
85
84
86
85
85
1075
B/T2-40/3
12.5
2.7
85
1062.5
Volume
B/T2-50/1
13.2
3.35
85
1122
50%
B/T2-50/2
12.55
3.45
85
1066.75
B/T2-50/3
13.55
3.3
85
1151.75
Volume
30%
Volume
40%
Luas
2
1079.5
1117.2
1113.7
1066.75
1117.75
Tebal 3 mm
Jenis
No
Lebar
Tebal
(mm)
Panjang
Awal
(mm)
komposit
Spesimen
(mm)
Volume
B/T3-20/1
20%
Luas
(mm )
14.05
3.15
101
1419.05
B/T3-20/2
15.05
3.2
101
1520.05
B/T3-20/3
12.15
3.15
102
1239.3
Volume
B/T3-30/1
12.65
4.45
100
1265
30%
B/T3-30/2
13.3
4.3
100
1330
B/T3-30/3
11.7
4.2
100
1170
Volume
B/T3-40/1
12.55
3.55
101
1267.55
40%
B/T3-40/2
13.5
3.7
100
1350
B/T3-40/3
14.3
3.7
100
1430
Volume
B/T3-50/1
13.15
4.5
100
1315
50%
B/T3-50/2
13.25
4.2
100
1325
B/T3-50/3
13.15
4.6
100
1315
2
Tebal 4 mm
Jenis
No
Lebar
Tebal
(mm)
Panjang
Awal
(mm)
komposit
Spesimen
(mm)
Volume
B/T4-20/1
20%
Luas
(mm )
13.9
4.4
115
1598.5
B/T4-20/2
12.95
4.25
114
1476.3
B/T4-20/3
13.75
4.2
114
1567.5
Volume
B/T4-30/1
12.7
4.7
114
1447.8
30%
B/T4-30/2
13.3
4.6
114
1516.2
B/T4-30/3
12.65
4.7
115
1454.75
Volume
B/T4-40/1
13.25
5.35
115
1523.75
40%
B/T4-40/2
14.5
5.45
114
1653
B/T4-40/3
13.15
5.55
115
1512.25
Volume
B/T4-50/1
13.3
5.15
115
1529.5
50%
B/T4-50/2
12.6
5.25
115
1449
B/T4-50/3
12.25
5.05
115
1408.75
2
Tebal 5 mm
Jenis
No
Lebar
Tebal
(mm)
Panjang
Awal
(mm)
komposit
Spesimen
(mm)
Volume
B/T5-20/1
20%
Luas
(mm )
14
5.4
130
1820
B/T5-20/2
13
5.45
130
1690
B/T5-20/3
14.85
5.55
130
1930.5
Volume
B/T5-30/1
12.9
5.25
130
1677
30%
B/T5-30/2
12.85
5.4
130
1670.5
B/T5-30/3
12.5
5.25
130
1625
Volume
B/T5-40/1
12.45
6.05
130
1618.5
40%
B/T5-40/2
13.75
5.6
129
1773.75
B/T5-40/3
12.8
5.75
130
1664
Volume
B/T5-50/1
13
7.05
130
1690
50%
B/T5-50/2
12.4
7
130
1612
B/T5-50/3
13.15
6.8
131
1722.65
Luas
(mm2)
2
Alkali 4 jam
Tebal 1 mm
Jenis
No
Lebar
Tebal
komposit
Spesimen
(mm)
(mm)
Panjang
Awal
(mm)
Volume
B/T1-20/1
12
1.35
66
792
20%
B/T1-20/2
13.05
1.35
66
861.3
B/T1-20/3
12.6
1.35
69
869.4
Volume
B/T1-30/1
11.95
1.55
68
812.6
30%
B/T1-30/2
12.95
1.8
69
893.55
B/T1-30/3
12.75
1.7
68
867
Volume
B/T1-40/1
12.7
2.3
67
850.9
40%
B/T1-40/2
12.95
2.25
67
867.65
B/T1-40/3
13.3
2.3
68
904.4
Volume
B/T1-50/1
13.65
1.9
68
928.2
50%
B/T1-50/2
13.05
1.95
68
887.4
B/T1-50/3
12.9
1.9
67
864.3
Tebal 2 mm
Jenis
No
Lebar
Tebal
Panjang
Awal
(mm)
komposit
Spesimen
(mm)
(mm)
Volume
B/T2-20/1
12.45
20%
B/T2-20/2
(mm )
2.1
86
1070.7
12.75
2.1
86
1096.5
B/T2-20/3
B/T2-30/1
B/T2-30/2
B/T2-30/3
B/T2-40/1
B/T2-40/2
12.5
12.7
13.3
12.95
12.55
13.15
2.15
2.8
2.85
2.8
2.75
2.75
86
85
84
86
85
85
1075
B/T2-40/3
12.5
2.7
85
1062.5
Volume
B/T2-50/1
13.2
3.35
85
1122
50%
B/T2-50/2
12.55
3.45
85
1066.75
B/T2-50/3
13.55
3.3
85
1151.75
Volume
30%
Volume
40%
Luas
2
1079.5
1117.2
1113.7
1066.75
1117.75
Tebal 3 mm
Jenis
No
Lebar
Tebal
Panjang
Awal
(mm)
Luas
komposit
Spesimen
(mm)
(mm)
Volume
B/T3-20/1
14.05
3.15
101 1419.05
20%
B/T3-20/2
15.05
3.2
101 1520.05
B/T3-20/3
12.15
3.15
102
1239.3
Volume
B/T3-30/1
12.65
4.45
100
1265
30%
B/T3-30/2
13.3
4.3
100
1330
B/T3-30/3
11.7
4.2
100
1170
Volume
B/T3-40/1
12.55
3.55
40%
B/T3-40/2
13.5
3.7
100
1350
B/T3-40/3
14.3
3.7
100
1430
Volume
B/T3-50/1
13.15
4.5
100
1315
50%
B/T3-50/2
13.25
4.2
100
1325
B/T3-50/3
13.15
4.6
100
1315
2
(mm )
101 1267.55
Tebal 4 mm
Jenis
No
Lebar
Tebal
Panjang
Awal
(mm)
komposit
Spesimen
(mm)
(mm)
Volume
B/T4-20/1
13.9
20%
B/T4-20/2
Luas
(mm )
4.4
115
1598.5
12.95
4.25
114
1476.3
B/T4-20/3
13.75
4.2
114
1567.5
Volume
B/T4-30/1
13.3
5.15
115
1529.5
30%
B/T4-30/2
12.6
5.25
115
1449
B/T4-30/3
12.25
5.05
115
1408.75
Volume
B/T4-40/1
13.25
5.35
115
1523.75
40%
B/T4-40/2
14.5
5.45
114
1653
B/T4-40/3
13.15
5.55
115
1512.25
Volume
B/T4-50/1
12.7
4.7
114
1447.8
50%
B/T4-50/2
13.3
4.6
114
1516.2
B/T4-50/3
12.65
4.7
115
1454.75
2
Tebal 5 mm
Jenis
No
Lebar
Tebal
Panjang
Awal
(mm)
komposit
Spesimen
(mm)
(mm)
Volume
B/T5-20/1
14
20%
B/T5-20/2
Luas
(mm )
5.4
130
1820
13
5.45
130
1690
B/T5-20/3
14.85
5.55
130
1930.5
Volume
B/T5-30/1
12.9
5.25
130
1677
30%
B/T5-30/2
12.85
5.4
130
1670.5
B/T5-30/3
12.5
5.25
130
1625
Volume
B/T5-40/1
13
7.05
130
1690
40%
B/T5-40/2
12.4
7
130
1612
B/T5-40/3
13.15
6.8
131
1722.65
Volume
B/T5-50/1
12.45
6.05
130
1618.5
50%
B/T5-50/2
13.75
5.6
129
1773.75
B/T5-50/3
12.8
5.75
130
1664
2
Alkali 6 jam
Tebal 1 mm
Jenis
No
Lebar
Tebal
(mm)
Panjang
Awal
(mm)
komposit
Spesimen
(mm)
Volume
B/T1-20/1
20%
Luas
(mm )
12
1.35
66
792
B/T1-20/2
13.05
1.35
66
861.3
B/T1-20/3
12.6
1.35
69
869.4
Volume
B/T1-30/1
11.95
1.55
68
812.6
30%
B/T1-30/2
12.95
1.8
69
893.55
B/T1-30/3
12.75
1.7
68
867
Volume
B/T1-40/1
12.7
2.3
67
850.9
40%
B/T1-40/2
12.95
2.25
67
867.65
B/T1-40/3
13.3
2.3
68
904.4
Volume
B/T1-50/1
13.65
1.9
68
928.2
50%
B/T1-50/2
13.05
1.95
68
887.4
B/T1-50/3
12.9
1.9
67
864.3
Panjang
Awal
(mm)
Luas
(mm )
2
Tebal 2 mm
Jenis
No
Lebar
Tebal
komposit
Spesimen
(mm)
(mm)
Volume
B/T2-20/1
12.45
2.1
86
1070.7
20%
B/T2-20/2
12.75
2.1
86
1096.5
B/T2-20/3
B/T2-30/1
B/T2-30/2
B/T2-30/3
B/T2-40/1
B/T2-40/2
12.5
12.7
13.3
12.95
12.55
13.15
2.15
2.8
2.85
2.8
2.75
2.75
86
85
84
86
85
85
1075
B/T2-40/3
12.5
2.7
85
1062.5
Volume
B/T2-50/1
13.2
3.35
85
1122
50%
B/T2-50/2
12.55
3.45
85
1066.75
B/T2-50/3
13.55
3.3
85
1151.75
Volume
30%
Volume
40%
2
1079.5
1117.2
1113.7
1066.75
1117.75
Tebal 3 mm
Jenis
No
Lebar
Tebal
(mm)
Panjang
Awal
(mm)
komposit
Spesimen
(mm)
Volume
B/T3-20/1
20%
Luas
(mm )
14.05
3.15
101
1419.05
B/T3-20/2
15.05
3.2
101
1520.05
B/T3-20/3
12.15
3.15
102
1239.3
Volume
B/T3-30/1
12.65
4.45
100
1265
30%
B/T3-30/2
13.3
4.3
100
1330
B/T3-30/3
11.7
4.2
100
1170
Volume
B/T3-40/1
12.55
3.55
101
1267.55
40%
B/T3-40/2
13.5
3.7
100
1350
B/T3-40/3
14.3
3.7
100
1430
Volume
B/T3-50/1
13.15
4.5
100
1315
50%
B/T3-50/2
13.25
4.2
100
1325
B/T3-50/3
13.15
4.6
100
1315
Luas
(mm )
2
Tebal 4 mm
Jenis
No
Lebar
Tebal
komposit
Spesimen
(mm)
(mm)
Panjang
Awal
(mm)
Volume
B/T4-20/1
13.9
4.4
115
1598.5
20%
B/T4-20/2
12.95
4.25
114
1476.3
B/T4-20/3
13.75
4.2
114
1567.5
Volume
B/T4-30/1
12.7
4.7
114
1447.8
30%
B/T4-30/2
13.3
4.6
114
1516.2
B/T4-30/3
12.65
4.7
115
1454.75
Volume
B/T4-40/1
13.25
5.35
115
1523.75
40%
B/T4-40/2
14.5
5.45
114
1653
B/T4-40/3
13.15
5.55
115
1512.25
Volume
B/T4-50/1
13.3
5.15
115
1529.5
50%
B/T4-50/2
12.6
5.25
115
1449
B/T4-50/3
12.25
5.05
115
1408.75
2
Tebal 5 mm
Jenis
No
Lebar
Tebal
(mm)
Panjang
Awal
(mm)
komposit
Spesimen
(mm)
Luas
(mm )
2
Volume
B/T5-20/1
14
5.4
130
1820
20%
B/T5-20/2
13
5.45
130
1690
B/T5-20/3
14.85
5.55
130
1930.5
Volume
B/T5-30/1
12.9
5.25
130
1677
30%
B/T5-30/2
12.85
5.4
130
1670.5
B/T5-30/3
12.5
5.25
130
1625
Volume
B/T5-40/1
12.45
6.05
130
1618.5
40%
B/T5-40/2
13.75
5.6
129
1773.75
B/T5-40/3
12.8
5.75
130
1664
Volume
B/T5-50/1
13
7.05
130
1690
50%
B/T5-50/2
12.4
7
130
1612
B/T5-50/3
13.15
6.8
131
1722.65
Luas
(mm )
Alkali 8 jam
Tebal 1 mm
Jenis
No
Lebar
Tebal
komposit
Spesimen
(mm)
(mm)
Panjang
Awal
(mm)
Volume
B/T1-20/1
12
1.35
66
792
20%
B/T1-20/2
13.05
1.35
66
861.3
B/T1-20/3
12.6
1.35
69
869.4
Volume
B/T1-30/1
11.95
1.55
68
812.6
30%
B/T1-30/2
12.95
1.8
69
893.55
B/T1-30/3
12.75
1.7
68
867
Volume
B/T1-40/1
12.7
2.3
67
850.9
40%
B/T1-40/2
12.95
2.25
67
867.65
B/T1-40/3
13.3
2.3
68
904.4
Volume
B/T1-50/1
13.65
1.9
68
928.2
50%
B/T1-50/2
13.05
1.95
68
887.4
B/T1-50/3
12.9
1.9
67
864.3
2
Tebal 2 mm
Jenis
No
Lebar
Tebal
(mm)
Panjang
Awal
(mm)
komposit
Spesimen
(mm)
Volume
B/T2-20/1
20%
(mm )
12.45
2.1
86
1070.7
B/T2-20/2
12.75
2.1
86
1096.5
B/T2-20/3
B/T2-30/1
B/T2-30/2
B/T2-30/3
B/T2-40/1
B/T2-40/2
12.5
12.7
13.3
12.95
12.55
13.15
2.15
2.8
2.85
2.8
2.75
2.75
86
85
84
86
85
85
1075
B/T2-40/3
12.5
2.7
85
1062.5
Volume
B/T2-50/1
13.2
3.35
85
1122
50%
B/T2-50/2
12.55
3.45
85
1066.75
B/T2-50/3
13.55
3.3
85
1151.75
Panjang
Awal
(mm)
Luas
Volume
30%
Volume
40%
Luas
2
1079.5
1117.2
1113.7
1066.75
1117.75
Tebal 3 mm
Jenis
No
Lebar
Tebal
komposit
Spesimen
(mm)
(mm)
Volume
B/T3-20/1
14.05
3.15
101
1419.05
20%
B/T3-20/2
15.05
3.2
101
1520.05
B/T3-20/3
12.15
3.15
102
1239.3
Volume
B/T3-30/1
12.65
4.45
100
1265
30%
B/T3-30/2
13.3
4.3
100
1330
B/T3-30/3
11.7
4.2
100
1170
Volume
B/T3-40/1
12.55
3.55
101
1267.55
40%
B/T3-40/2
13.5
3.7
100
1350
B/T3-40/3
14.3
3.7
100
1430
Volume
B/T3-50/1
13.15
4.5
100
1315
50%
B/T3-50/2
13.25
4.2
100
1325
B/T3-50/3
13.15
4.6
100
1315
2
(mm )
Tebal 4 mm
Jenis
No
Lebar
Tebal
(mm)
Panjang
Awal
(mm)
komposit
Spesimen
(mm)
Volume
B/T4-20/1
20%
Luas
(mm )
13.9
4.4
115
1598.5
B/T4-20/2
12.95
4.25
114
1476.3
B/T4-20/3
13.75
4.2
114
1567.5
Volume
B/T4-30/1
12.7
4.7
114
1447.8
30%
B/T4-30/2
13.3
4.6
114
1516.2
B/T4-30/3
12.65
4.7
115
1454.75
Volume
B/T4-40/1
13.25
5.35
115
1523.75
40%
B/T4-40/2
14.5
5.45
114
1653
B/T4-40/3
13.15
5.55
115
1512.25
Volume
B/T4-50/1
13.3
5.15
115
1529.5
50%
B/T4-50/2
12.6
5.25
115
1449
B/T4-50/3
12.25
5.05
115
1408.75
Panjang
Awal
(mm)
Luas
(mm )
2
Tebal 5 mm
Jenis
No
Lebar
Tebal
komposit
Spesimen
(mm)
(mm)
Volume
B/T5-20/1
14
5.4
130
1820
20%
B/T5-20/2
13
5.45
130
1690
B/T5-20/3
14.85
5.55
130
1930.5
Volume
B/T5-30/1
12.9
5.25
130
1677
30%
B/T5-30/2
12.85
5.4
130
1670.5
B/T5-30/3
12.5
5.25
130
1625
Volume
B/T5-40/1
12.45
6.05
130
1618.5
40%
B/T5-40/2
13.75
5.6
B/T5-40/3
12.8
5.75
130
1664
Volume
B/T5-50/1
13
7.05
130
1690
50%
B/T5-50/2
12.4
7
130
1612
B/T5-50/3
13.15
6.8
2
129 1773.75
131 1722.65
Tabel.2.2.Data Pengujian Tarik Alkali 2 jam
Specimen
20% T1
30% T1
40% T1
50% T1
20% T2
30% T2
40% T2
50% T2
20% T3
30% T3
40% T3
50% T3
20% T4
panjang
awal
33
32
33
31
32
33
31
32
33
31
31
32
32.5
32
33
33.5
34
33
32
33
31.7
32.5
32.6
32.5
33
34
33.5
32
31.8
32.2
33.5
33
31.6
32
32
33.6
33
34
lebar
tebal
G (Kgf)
ε (mm)
luas
6
6.5
7
6
6
7
7
6.5
6.5
6
7
7
6
6.5
6.4
6
5.9
5
6
6.5
7
6.8
6
5.5
6.5
6.2
6
7
6.3
7
7
6.3
5.8
5.5
6
5.4
6
6.5
1.35
1.35
1.35
1.55
1.8
1.7
1.6
1.5
1.5
1.9
1.95
1.9
2.5
2
2.4
2.8
2.5
2.4
2.2
2.4
2.5
2.3
2.4
2.4
3.2
3
3
3.5
3.5
2.8
3
3.4
3
3.4
3.2
3.4
4.4
3.8
15.11
17.26
10.01
2.82
18.81
28.49
24.74
18.97
15.48
45.98
18.77
28.49
25.65
30.55
28.33
42.30
38.76
34.10
74.55
38.35
45.52
60.54
84.13
48.84
62.75
43.72
34.46
80.07
64.64
55.89
66.77
108.96
114.68
127.86
125.02
80.02
98.43
77.49
0.71
1.25
0.61
0.57
0.81
1.09
0.62
1.12
0.78
0.83
0.73
1.09
0.42
0.43
0.39
0.43
0.48
0.59
0.60
0.50
0.42
0.52
0.75
0.46
0.58
0.32
0.26
0.79
0.41
0.30
0.54
0.77
0.08
0.64
0.86
0.44
0.86
0.89
198
208
231
186
192
231
217
208
214.5
186
217
224
195
208
211.2
201
200.6
165
192
214.5
221.9
221
195.6
178.75
214.5
210.8
201
224
200.34
225.4
234.5
207.9
183.28
176
192
181.44
198
221
30% T4
40% T4
50% T4
20% T5
30% T5
40% T5
50% T5
32.5
31.8
32
32
32.6
33.2
33.4
33
32
33.4
33
32.5
32.6
33
32
34
33
32.8
33.5
33.2
34
33.5
6
7
6.5
7
6
7
6.3
6.5
7
7
7
7
6.5
6.4
6
6
6.4
6.5
7
6.8
6.4
6
4.2
3.9
4.2
4.5
4
4.6
4.8
3.5
4.2
4.5
4.8
5
5.4
6
5.5
4.8
5
5.2
5.5
6
6.2
5.5
94.56
91.53
77.80
78.77
127.72
137.73
125.54
319.83
172.29
309.66
163.42
209.19
200.10
136.29
248.40
127.59
158.43
251.41
224.02
257.15
220.72
345.19
0.78
0.79
0.55
0.59
1.28
1.29
1.21
1.48
0.88
1.49
1.59
1.39
1.36
1.49
1.52
1.61
1.43
1.49
1.53
1.68
1.63
1.25
195
222.6
208
224
195.6
232.4
210.42
214.5
224
233.8
231
227.5
211.9
211.2
192
204
211.2
213.2
234.5
225.76
217.6
201
panjang
awal
33.5
33
32
31
32
33
31
32
33
31
32
32
32
32
33
33
34
33
lebar
tebal
G (Kgf)
ε (mm)
luas
6.5
6.5
7
6
6
7
7
6.5
6
6
7
6.5
6
6.5
6.4
6
5.9
5
1.35
1.35
1.35
1.55
1.8
1.7
1.6
1.5
1.5
1.9
1.95
1.9
2.5
2
2.4
2.8
2.5
2.4
13.70
14.79
25.21
11.47
15.48
20.55
38.86
38.82
40.79
27.27
30.18
35.88
60.34
36.52
13.32
52.00
20.76
23.57
1.86
0.85
0.73
0.73
0.78
0.85
0.94
1.19
1.88
0.57
0.78
0.91
0.61
0.39
1.40
1.00
1.21
1.10
217.75
214.5
224
186
192
231
217
208
198
186
224
208
192
208
211.2
198
200.6
165
Alkali 4 jam
Specimen
20% T1
30% T1
40% T1
50% T1
20% T2
30% T2
40% T2
50% T2
20% T3
30% T3
40% T3
50% T3
20% T4
30% T4
40% T4
50% T4
20% T5
30% T5
40% T5
50% T5
32
33
32
32.5
32
33
33
32
33
32
31.8
32.2
32
33
31.6
32
32
32
33
33
32.5
31.8
32
32
32.6
33.2
33.4
33
32
32
33
32
32
33
32
34
33
32.8
32
33.2
33
32
6
6.5
7
6.5
6
5.5
6.5
6.2
6
7
6.3
7
7
6.3
6
5.5
6
5.4
6
6.5
6
7
6.5
6.5
6
7
6.3
6.5
7
7
6.5
7
6.5
6.4
6
6
6.4
6.5
7
6.8
6.4
6
2.2
2.4
2.5
2.3
2.4
2.4
3.2
3
3
3.5
3.5
2.8
3
3.4
3
3.4
3.2
3.4
4.4
3.8
4.2
3.9
4.2
4.5
4
4.6
4.8
3.5
4.2
4.5
4.8
5
5.4
6
5.5
4.8
5
5.2
5.5
6
6.2
5.5
94.98
65.43
50.86
103.69
91.18
89.72
43.55
46.90
85.45
82.52
82.76
85.17
56.49
60.89
79.80
155.46
144.68
119.87
66.35
71.89
112.86
82.94
103.34
135.73
120.04
102.73
90.39
178.03
157.93
135.01
58.43
68.37
70.40
77.97
81.95
120.52
111.37
102.96
115.76
233.21
202.29
180.90
0.85
0.59
0.56
0.71
0.77
0.57
0.33
0.32
0.58
0.65
0.68
0.58
0.34
0.48
0.86
1.04
0.81
0.54
0.35
0.53
0.61
0.60
0.57
0.86
0.68
0.60
0.37
1.29
0.65
0.60
0.57
0.36
0.34
0.37
0.45
0.56
0.47
0.71
0.55
1.14
0.67
0.66
192
214.5
224
211.25
192
181.5
214.5
198.4
198
224
200.34
225.4
224
207.9
189.6
176
192
172.8
198
214.5
195
222.6
208
208
195.6
232.4
210.42
214.5
224
224
214.5
224
208
211.2
192
204
211.2
213.2
224
225.76
211.2
192
Alkali 6 jam
Specimen
20% T1
30% T1
40% T1
50% T1
20% T2
30% T2
40% T2
50% T2
20% T3
30% T3
40% T3
50% T3
20% T4
30% T4
panjang
awal
33.5
33
32
31
32
33
31
32
33
31
32
32
32
32
33
33
34
33
32
33
32
32.5
32
33
33
32
33
32
31.8
32.2
32
33
31.6
32
32
32
33
33
32.5
31.8
lebar
tebal
G (Kgf)
ε (mm)
luas
6
6
6.5
6
6
6.5
7
6.5
6
6
7
6
6.5
6
6
6
5.9
5.5
6
6.5
7
6.5
6
7
6.5
6.2
6
7
6.5
7
7
6.5
6
6
6
5.8
6.5
6
6
7
1.35
1.35
1.35
1.55
1.8
1.7
1.6
1.5
1.5
1.9
1.95
1.9
2.5
2
2.4
2.8
2.5
2.4
2.2
2.4
2.5
2.3
2.4
2.4
3.2
3
3
3.5
3.5
2.8
3
3.4
3
3.4
3.2
3.4
4.4
3.8
4.2
3.9
12.59
9.31
15.46
24.29
21.44
17.57
34.45
33.09
21.19
40.85
56.25
47.83
32.35
49.06
31.11
30.48
45.75
40.18
139.26
92.20
72.02
120.13
90.28
125.17
60.03
49.56
61.05
76.84
83.30
62.99
132.56
96.43
88.11
116.83
153.67
121.47
71.09
65.62
73.81
99.75
0.85
0.47
0.77
0.80
1.45
0.79
0.58
1.21
1.48
0.60
0.72
1.07
0.69
0.58
1.01
0.72
0.19
0.87
0.83
0.56
0.55
1.18
0.88
0.95
0.75
0.39
0.48
0.42
0.62
0.40
1.00
0.70
0.61
0.63
0.80
0.68
0.38
0.48
0.53
0.58
201
198
208
186
192
214.5
217
208
198
186
224
192
208
192
198
198
200.6
181.5
192
214.5
224
211.25
192
231
214.5
198.4
198
224
206.7
225.4
224
214.5
189.6
192
192
185.6
214.5
198
195
222.6
40% T4
50% T4
20% T5
30% T5
40% T5
50% T5
32
32
32.6
33.2
33.4
33
32
32
33
32
32
33
32
34
33
32.8
32
33.2
33
32
6.5
6
6
7
6.3
6.5
7
7
6
6.5
6
6.5
6
6
6.5
6.5
7
6.8
6.5
7
4.2
4.5
4
4.6
4.8
3.5
4.2
4.5
4.8
5
5.4
6
5.5
4.8
5
5.2
5.5
6
6.2
5.5
114.03
124.88
180.71
112.29
129.32
111.72
106.23
144.42
64.43
118.95
78.69
130.66
108.82
125.92
125.79
159.07
144.85
207.68
186.31
291.33
0.54
0.61
1.04
0.56
0.78
0.54
0.52
0.75
0.42
0.59
0.48
0.57
0.64
0.62
0.83
0.92
0.86
0.87
0.64
1.15
208
192
195.6
232.4
210.42
214.5
224
224
198
208
192
214.5
192
204
214.5
213.2
224
225.76
214.5
224
panjang
awal
33.5
33
32
31
32
33
31
32
33
31
32
32
32
32
33
33
34
33
32
33
lebar
tebal
G (Kgf)
ε (mm)
luas
6
6
6.5
6
6
6.5
7
6.5
6
6
7
6
6.5
6
6
6
5.9
5.5
6
6.5
1.35
1.35
1.35
1.55
1.8
1.7
1.6
1.5
1.5
1.9
1.95
1.9
2.5
2
2.4
2.8
2.5
2.4
2.2
2.4
10.27
13.35
13.81
30.63
19.22
23.46
34.70
11.78
25.72
45.01
33.42
29.98
14.72
35.54
37.12
55.00
41.10
38.10
89.79
74.64
0.50
0.70
0.90
0.67
0.79
0.51
0.92
1.16
0.88
0.73
0.48
0.42
1.25
0.37
0.60
0.55
0.49
0.48
0.59
0.46
201
198
208
186
192
214.5
217
208
198
186
224
192
208
192
198
198
200.6
181.5
192
214.5
Alkali 8 jam
Alkali 8 jam
20% T1
30% T1
40% T1
50% T1
20% T2
30% T2
40% T2
50% T2
20% T3
30% T3
40% T3
50% T3
20% T4
30% T4
40% T4
50% T4
20% T5
30% T5
40% T5
50% T5
32
32.5
32
33
33
32
33
32
31.8
32.2
32
33
31.6
32
32
32
33
33
32.5
31.8
32
32
32.6
33.2
33.4
33
32
32
33
32
32
33
32
34
33
32.8
32
33.2
33
32
7
6.5
6
7
6.5
6.2
6
7
6.5
7
7
6.5
6
6
6
5.8
6.5
6
6
7
6.5
6
6
7
6.3
6.5
6.4
6.5
6
6.5
6
6.5
6
6
6.5
6.5
7
6
6.5
6
2.5
2.3
2.4
2.4
3.2
3
3
3.5
3.5
2.8
3
3.4
3
3.4
3.2
3.4
4.4
3.8
4.2
3.9
4.2
4.5
4
4.1
4.2
4
4.2
4.5
4.8
5
5.4
6
5.5
4.8
5
5.2
5.5
5.5
5
5
68.48
80.15
84.61
78.18
45.11
71.02
50.15
84.17
71.81
65.18
98.74
82.27
91.63
143.88
161.82
144.87
73.54
61.84
70.59
78.84
92.61
89.34
135.75
131.02
103.38
196.27
286.62
159.26
131.07
99.55
114.77
108.42
128.26
141.13
195.08
164.91
166.88
134.14
166.02
143.77
0.58
0.50
0.52
0.68
0.35
0.47
0.77
0.75
0.56
0.47
0.78
0.56
0.56
0.81
0.90
0.79
0.47
0.48
0.39
0.48
0.58
0.57
0.63
0.62
0.45
1.06
1.52
0.87
0.50
0.41
0.49
0.45
0.53
0.62
0.81
0.73
0.62
0.75
0.71
0.60
224
211.25
192
231
214.5
198.4
198
224
206.7
225.4
224
214.5
189.6
192
192
185.6
214.5
198
195
222.6
208
192
195.6
232.4
210.42
214.5
204.8
208
198
208
192
214.5
192
204
214.5
213.2
224
199.2
214.5
192
Tabel.2.3.Data Pengujian Impak Alkali 2 jam
Jenis
komposit
No
Spesimen
Tebal
(mm)
Lebar
(mm)
Luas
penampang
dibawah
takik (mm²)
Harga
impak
(J/mm²)
Volume
I/T1-20/1
1.25
4.55
5.69
0.4
20%
I/T1-20/2
1.3
4.35
5.66
0.4
I/T1-20/3
1.2
5.05
6.06
0.5
Volume
I/T1-30/1
1.25
5.5
6.88
0.5
30%
I/T1-30/2
1.55
5.7
8.84
0.4
I/T1-30/3
1.5
5.75
8.63
0.5
Volume
I/T1-40/1
2.15
5.75
12.36
0.6
40%
I/T1-40/2
2.15
4.85
10.43
0.6
I/T1-40/3
2.15
4.9
10.54
0.7
Volume
I/T1-50/1
1.95
4.55
8.87
0.8
50%
I/T1-50/2
2.2
5.65
12.43
0.7
I/T1-50/3
1.7
5.1
8.67
0.7
Volume
I/T2-20/1
2.1
4.8
10.08
0.8
20%
I/T2-20/2
2.1
5.3
11.13
1
I/T2-20/3
2.1
5.1
10.71
0.8
Volume
I/T2-30/1
2.55
6.15
15.68
0.8
30%
I/T2-30/2
2.6
6.15
15.99
0.7
I/T2-30/3
2.65
5.85
15.50
0.8
Volume
I/T2-40/1
2.95
5.2
15.34
0.7
40%
I/T2-40/2
2.8
5.5
15.40
0.5
I/T2-40/3
3
5.95
17.85
0.6
Volume
I/T2-50/1
3.55
5.25
18.64
1
50%
I/T2-50/2
3.75
5.25
19.69
0.9
I/T2-50/3
3.75
5.2
19.50
1
Volume
I/T3-20/1
3.3
5.35
17.66
1
20%
I/T3-20/2
3.15
5.25
16.54
1.1
I/T3-20/3
3.2
4.95
15.84
1.1
Volume
I/T3-30/1
4.15
5.15
21.37
1.2
30%
I/T3-30/2
3.3
5.4
17.82
1.1
I/T3-30/3
3.4
5.05
17.17
1.1
Volume
I/T3-40/1
4.1
5.4
22.14
1.1
40%
I/T3-40/2
3.05
5.5
16.78
1.1
I/T3-40/3
4.05
5.15
20.86
1.3
Volume
I/T3-50/1
4.35
4.95
21.53
1
50%
I/T3-50/2
4.2
5.3
22.26
1.1
I/T3-50/3
3.8
5.8
22.04
1.1
Volume
I/T4-20/1
3.95
4.95
19.55
1.4
20%
I/T4-20/2
4.05
5.25
21.26
1.4
I/T4-20/3
4.05
5.1
20.66
1.5
Volume
I/T4-30/1
4.5
6
27.00
1.1
30%
I/T4-30/2
4.4
5.35
23.54
1.1
I/T4-30/3
4.2
5.65
23.73
1.2
Volume
I/T4-40/1
4.4
5.85
25.74
1.2
40%
I/T4-40/2
4.1
6.2
25.42
1.3
I/T4-40/3
3.95
6.35
25.08
1.3
Volume
I/T4-50/1
4.75
5.95
28.26
1.5
50%
I/T4-50/2
4.2
5.55
23.31
1.6
I/T4-50/3
4.5
4.45
20.03
1.4
Volume
I/T5-20/1
5.2
5.7
29.64
1.7
20%
I/T5-20/2
5.4
5.3
28.62
1.7
I/T5-20/3
5
5.25
26.25
1.6
Volume
I/T5-30/1
5.3
5.55
29.42
1.6
30%
I/T5-30/2
5.5
4.9
26.95
1.7
I/T5-30/3
5.2
5.15
26.78
1.6
Volume
I/T5-40/1
5.4
5.2
28.08
1.7
40%
I/T5-40/2
5.1
5.25
26.78
1.8
I/T5-40/3
5.2
5.75
29.90
1.7
Volume
I/T5-50/1
5.1
5.5
28.05
1.8
50%
I/T5-50/2
5
5.55
27.75
1.7
I/T5-50/3
5
6
30
1.6
Alkali 4 jam
Jenis
komposit
No
Spesimen
Tebal
(mm)
Lebar
(mm)
Luas
penampang
dibawah
takik (mm²)
Harga
impak
(J/mm²)
Volume
I/T1-20/1
1
5
6.24
0.5
20%
I/T1-20/2
1.25
4.55
5.69
0.6
I/T1-20/3
1.2
5.05
6.06
0.4
Volume
I/T1-30/1
1.25
5.5
6.88
0.5
30%
I/T1-30/2
1.55
5.7
8.84
0.5
I/T1-30/3
1.5
5.75
8.63
0.6
Volume
I/T1-40/1
2.15
5.75
12.36
0.7
40%
I/T1-40/2
2.15
4.85
10.43
0.6
I/T1-40/3
2.15
4.9
10.54
0.7
Volume
I/T1-50/1
1.95
4.55
8.87
0.8
50%
I/T1-50/2
2.2
5.65
12.43
0.7
I/T1-50/3
1.7
5.1
8.67
0.8
Volume
I/T2-20/1
2.1
4.8
10.08
0.8
20%
I/T2-20/2
2.1
5.3
11.13
0.8
I/T2-20/3
2.1
5.1
10.71
0.9
Volume
I/T2-30/1
2.55
6.15
15.68
0.9
30%
I/T2-30/2
2.6
6.15
15.99
0.8
I/T2-30/3
2.65
5.85
15.50
0.7
Volume
I/T2-40/1
2.95
5.2
15.34
0.8
40%
I/T2-40/2
2.8
5.5
15.40
0.7
I/T2-40/3
3
5.95
17.85
0.6
Volume
I/T2-50/1
3.55
5.25
18.64
0.9
50%
I/T2-50/2
3.75
5.25
19.69
1
I/T2-50/3
3.75
5.2
19.50
1.1
Volume
I/T3-20/1
3.3
5.35
17.66
1.1
20%
I/T3-20/2
3.15
5.25
16.54
1.1
I/T3-20/3
3.2
4.95
15.84
1.2
Volume
I/T3-30/1
4.15
5.15
21.37
1.3
30%
I/T3-30/2
3.3
5.4
17.82
1.1
I/T3-30/3
3.4
5.05
17.17
1.3
I/T3-40/1
4.1
5.4
22.14
1.1
Volume
40%
I/T3-40/2
3.05
5.5
16.78
1
I/T3-40/3
4.05
5.15
20.86
1.1
Volume
I/T3-50/1
4.35
4.95
21.53
1.4
50%
I/T3-50/2
4.2
5.3
22.26
1.4
I/T3-50/3
3.8
5.8
22.04
1.5
Volume
I/T4-20/1
3.95
4.95
19.55
1.5
20%
I/T4-20/2
4.05
5.25
21.26
1.4
I/T4-20/3
4.05
5.1
20.66
1.5
Volume
I/T4-30/1
4.5
6
27.00
1.1
30%
I/T4-30/2
4.4
5.35
23.54
1.3
I/T4-30/3
4.2
5.65
23.73
1.3
Volume
I/T4-40/1
4.4
5.85
25.74
1.4
40%
I/T4-40/2
4.1
6.2
25.42
1.6
I/T4-40/3
3.95
6.35
25.08
1.6
Volume
I/T4-50/1
4.75
5.95
28.26
1.7
50%
I/T4-50/2
4.2
5.55
23.31
1.5
I/T4-50/3
4.5
4.45
20.03
1.5
Volume
I/T5-20/1
5.2
5.7
29.64
1.4
20%
I/T5-20/2
5.4
5.3
28.62
1.5
I/T5-20/3
5
5.25
26.25
1.5
Volume
I/T5-30/1
5.3
5.55
29.42
1.5
30%
I/T5-30/2
5.5
4.9
26.95
1.7
I/T5-30/3
5.2
5.15
26.78
1.7
Volume
I/T5-40/1
5.4
5.2
28.08
1.8
40%
I/T5-40/2
5.1
5.25
26.78
1.7
I/T5-40/3
5.2
5.75
29.90
1.8
Volume
I/T5-50/1
5.1
5.5
28.05
1.8
50%
I/T5-50/2
5
5.55
27.75
1.7
I/T5-50/3
5
6
30
1.8
Alkali 6 jam
Jenis
komposit
No
Spesimen
Tebal
(mm)
Lebar
(mm)
Luas
penampang
dibawah
takik (mm²)
Harga
impak
(J/mm²)
Volume
I/T1-20/1
1
5
6.24
0.6
20%
I/T1-20/2
1.25
4.55
5.69
0.5
I/T1-20/3
1.2
5.2
6.24
0.5
Volume
I/T1-30/1
1.25
5.5
6.88
0.6
30%
I/T1-30/2
1.55
5.7
8.84
0.5
I/T1-30/3
1.5
5.75
8.63
0.4
Volume
I/T1-40/1
2.15
5.75
12.36
0.5
40%
I/T1-40/2
1.75
4.85
8.49
0.6
I/T1-40/3
1.95
4.9
9.56
0.6
Volume
I/T1-50/1
1.95
4.55
8.87
0.6
50%
I/T1-50/2
2.1
5.65
11.87
0.8
I/T1-50/3
1.7
5.1
8.67
0.7
Volume
I/T2-20/1
2.1
4.8
10.08
0.9
20%
I/T2-20/2
2.1
5.3
11.13
0.8
I/T2-20/3
2.1
5.1
10.71
1
Volume
I/T2-30/1
2.55
6.15
15.68
0.7
30%
I/T2-30/2
2.6
6.15
15.99
0.8
I/T2-30/3
2.65
5.85
15.50
0.7
Volume
I/T2-40/1
2.95
5.2
15.34
0.7
40%
I/T2-40/2
2.8
5.5
15.40
0.8
I/T2-40/3
2.7
5.95
16.07
0.9
Volume
I/T2-50/1
2.85
5.25
14.96
1.1
50%
I/T2-50/2
2.55
5.25
13.39
1.1
I/T2-50/3
2.56
5.2
13.31
1.2
Volume
I/T3-20/1
3.3
5.35
17.66
1
20%
I/T3-20/2
3.15
5.25
16.54
1.1
I/T3-20/3
3.2
4.95
15.84
0.9
Volume
I/T3-30/1
4.15
5.15
21.37
1.2
30%
I/T3-30/2
3.3
5.4
17.82
1.3
I/T3-30/3
3.4
5.05
17.17
1.3
I/T3-40/1
4.1
5.4
22.14
1.3
Volume
40%
I/T3-40/2
3.05
5.5
16.78
1.3
I/T3-40/3
4.05
5.15
20.86
1.2
Volume
I/T3-50/1
4.35
4.95
21.53
1.4
50%
I/T3-50/2
4.2
5.3
22.26
1.3
I/T3-50/3
3.8
5.8
22.04
1.3
Volume
I/T4-20/1
3.95
4.95
19.55
1.3
20%
I/T4-20/2
4.05
5.25
21.26
1.2
I/T4-20/3
4.05
5.1
20.66
1.2
Volume
I/T4-30/1
4.5
6
27.00
1.3
30%
I/T4-30/2
4.4
5.35
23.54
1.2
I/T4-30/3
4.2
5.65
23.73
1.3
Volume
I/T4-40/1
4.4
5.85
25.74
1.6
40%
I/T4-40/2
4.1
6.2
25.42
1.5
I/T4-40/3
3.95
6.35
25.08
1.5
Volume
I/T4-50/1
4.75
5.95
28.26
1.8
50%
I/T4-50/2
4.2
5.55
23.31
1.7
I/T4-50/3
4.5
4.45
20.03
1.7
Volume
I/T5-20/1
5.2
5.7
29.64
1.7
20%
I/T5-20/2
5.4
5.3
28.62
1.5
I/T5-20/3
5
5.25
26.25
1.5
Volume
I/T5-30/1
5.3
5.55
29.42
1.6
30%
I/T5-30/2
5.5
4.9
26.95
1.7
I/T5-30/3
5.2
5.15
26.78
1.7
Volume
I/T5-40/1
5.4
5.2
28.08
1.7
40%
I/T5-40/2
5.1
5.25
26.78
1.6
I/T5-40/3
5.2
5.75
29.90
1.8
Volume
I/T5-50/1
5.1
5.5
28.05
1.8
50%
I/T5-50/2
5.4
5.55
29.97
1.8
I/T5-50/3
5
5.65
28.25
1.9
Alkali 8 jam
Jenis
komposit
No
Spesimen
Tebal
(mm)
Lebar
(mm)
Luas
penampang
dibawah
takik (mm²)
Harga
impak
(J/mm²)
Volume
I/T1-20/1
1.50
5.25
7.88
0.4
20%
I/T1-20/2
1.25
4.85
6.06
0.6
I/T1-20/3
1.2
5.40
6.48
0.6
Volume
I/T1-30/1
1.25
5.5
6.88
0.4
30%
I/T1-30/2
1.55
5.7
8.84
0.6
I/T1-30/3
1.5
5.75
8.63
0.6
Volume
I/T1-40/1
2.15
5.75
12.36
0.6
40%
I/T1-40/2
1.75
4.85
8.49
0.7
I/T1-40/3
1.95
4.9
9.56
0.5
Volume
I/T1-50/1
1.95
4.55
8.87
0.8
50%
I/T1-50/2
2.10
5.65
11.87
0.9
I/T1-50/3
1.7
5.1
8.67
0.7
Volume
I/T2-20/1
2.1
4.80
10.08
0.7
20%
I/T2-20/2
2.1
5.3
11.13
0.9
I/T2-20/3
2.1
5.1
10.71
0.9
Volume
I/T2-30/1
2.55
6.15
15.68
0.8
30%
I/T2-30/2
2.6
6.15
15.99
1.1
I/T2-30/3
2.65
5.85
15.50
1
Volume
I/T2-40/1
2.95
5.2
15.34
0.9
40%
I/T2-40/2
2.8
5.5
15.40
0.8
I/T2-40/3
2.70
5.95
16.07
0.6
Volume
I/T2-50/1
2.85
5.25
14.96
1
50%
I/T2-50/2
2.55
5.25
13.39
0.9
I/T2-50/3
2.56
5.2
13.31
0.9
Volume
I/T3-20/1
3.3
5.35
17.66
1.1
20%
I/T3-20/2
3.15
5.25
16.54
1.1
I/T3-20/3
3.2
4.95
15.84
1.2
Volume
I/T3-30/1
4.15
5.15
21.37
1.1
30%
I/T3-30/2
3.3
5.4
17.82
1.2
I/T3-30/3
3.4
5.05
17.17
1.2
I/T3-40/1
4.1
5.4
22.14
1.2
Volume
40%
I/T3-40/2
3.05
5.5
16.78
1.3
I/T3-40/3
4.05
5.15
20.86
1.2
Volume
I/T3-50/1
4.35
4.95
21.53
1.4
50%
I/T3-50/2
4.2
5.3
22.26
1.3
I/T3-50/3
3.8
5.8
22.04
1.4
Volume
I/T4-20/1
3.95
4.95
19.55
1.2
20%
I/T4-20/2
4.05
5.25
21.26
1.1
I/T4-20/3
4.05
5.1
20.66
1.1
Volume
I/T4-30/1
4.5
6.00
27.00
1.4
30%
I/T4-30/2
4.4
5.35
23.54
1.5
I/T4-30/3
4.2
5.65
23.73
1.4
Volume
I/T4-40/1
4.4
5.85
25.74
1.5
40%
I/T4-40/2
4.1
6.2
25.42
1.4
I/T4-40/3
3.95
6.35
25.08
1.4
Volume
I/T4-50/1
4.75
5.95
28.26
1.8
50%
I/T4-50/2
4.2
5.55
23.31
1.6
I/T4-50/3
4.5
4.45
20.03
1.7
Volume
I/T5-20/1
5.2
5.7
29.64
1.6
20%
I/T5-20/2
5.4
5.3
28.62
1.7
I/T5-20/3
5.00
5.25
26.25
1.6
Volume
I/T5-30/1
5.3
5.55
29.42
1.7
30%
I/T5-30/2
5.5
4.9
26.95
1.6
I/T5-30/3
5.2
5.15
26.78
1.5
Volume
I/T5-40/1
5.4
5.2
28.08
1.8
40%
I/T5-40/2
5.1
5.25
26.78
1.7
I/T5-40/3
5.2
5.75
29.90
1.5
Volume
I/T5-50/1
5.1
5.00
25.50
1.9
50%
I/T5-50/2
5.25
5.45
28.61
1.7
I/T5-50/3
5.20
5.50
28.6
1.6
LAMPIRAN III
1. Pengujian Bending (Standart ASTM D 790-02)
Diketahui :
Tebal spesimen (d)
: 1,35 mm
Lebar spesimen (b)
: 12,00 mm
Panjang span (L)
: 25,4 mm
Gaya (P)
: 0,05 kN = 50 N
Penambahan panjang (∆L mesin)
: 4,68 mm
a. Defleksi


Lmesin
kotak
4,68mm
 0,78 mm (nilai per kotak)
6kotak
= 2,5 kotak x 0,78 = 1,95 mm
b. Momen bending
P
L
P/2
Mb =
=
P/2
½L
PL
4
50 N  25,4mm
4mm
=317,5 N
c. Tegangan bending


3PL
2bd 2
3  50 N  25,4mm
2  12 mm  1,35 mm 
2

3810 N .mm
43,74 mm 3
= 87,1056 N/mm2
d. Modulus elastisitas bending
PL3
E
4bd 3

50N  (25,4mm) 3
4  12mm  1,35mm  1,95mm
3
819353 ,2 N .mm 3

230 ,2911 mm 5
= 3557,902 N/mm2
e. Kekakuan bending (Lukasen, 1975)
I
= 1/12 x b x h3
= 1/12 x 12 mm x (1,35 mm)3
= 2,460 mm4
D =ExI
= 3557,902N/mm2 x 2,460 mm4
= 8753,773 Nmm2
2. Pengujian Impak (Standart ASTM D 256-00)
Diketahui :
Tebal spesimen (d)
: 1,25mm
Lebar spesimen (b)
: 4,55mm
Luas (Ao)
: 5,7 mm2
Energi Terpasang
: 21 J
Sudut α
: 300
Sudut β
: 29,50
Panjang Lengan (R)
: 0,8 m
: 10 m/s2
Percepatan gravitasi (g)
Berat Pendulum (m)
a. Esrp
: 20 kg
= mg.R.(cos β - cos α)
= 20kg. 10 m/s2 0,8 m(cos 29,5- cos 30)
= 160 kgm2/s2 (0,87-0,866)
= 0,69 kgm2/s2= 0,7 J
b. HI
=
Eserap
Ao
=
0,7 J
5,7 mm 2
= 0,122 J/mm2
3. Pengujian Tarik ( Standart ASTM D 638-02)
Diketahui :
Tebal spesimen (d)
: 1,35mm
Lebar spesimen (b)
: 6 mm
Panjang specimen (lo)
: 33 mm
Luas
(A)
: 198 mm2
Beban
(P)
:148,10 N
Regangan
()
:0,71 mm/mm
a. Tegangan Tarik
P= σ . A atau σ = P/A
=148,10 N / 198 mm2
=0,748 Mpa
b. Regangan Tarik

=
L
atau ΔL = x lo
lo
= 0,71 x 33
=23,43 mm
c. Modulus elastisitas tarik
E

= 
= 0,748 Mpa / 0,71 mm/mm
=1,048 Mpa.
Data Hasil Pengujian Impak Serat Rami Alkali 2 jam
Jenis
komposit
No
Spesimen
Harga
impak
(J/mm²)
Harga
impak
rata-rata
(j/mm²)
Energi
yang
terserap
(J)
Volume
I/T1-20/1
0.4
20%
I/T1-20/2
0.4
I/T1-20/3
0.5
Volume
I/T1-30/1
0.5
30%
I/T1-30/2
0.4
I/T1-30/3
0.5
4.31
Volume
I/T1-40/1
0.6
7.42
40%
I/T1-40/2
0.6
I/T1-40/3
0.7
7.37
Volume
I/T1-50/1
0.8
7.10
50%
I/T1-50/2
0.7
Energi
yang
terserap
rata-rata
(J)
2.28
0.433
2.26
2.522
3.03
3.44
0.467
0.700
0.733
3.53
6.26
8.70
I/T1-50/3
0.7
6.07
Volume
I/T2-20/1
0.8
8.06
20%
I/T2-20/2
1
I/T2-20/3
0.8
8.57
Volume
I/T2-30/1
0.8
12.55
30%
I/T2-30/2
0.7
I/T2-30/3
0.8
12.40
Volume
I/T2-40/1
0.7
10.74
40%
I/T2-40/2
0.5
I/T2-40/3
0.6
10.71
Volume
I/T2-50/1
1
18.64
50%
I/T2-50/2
0.9
I/T2-50/3
1
19.50
Volume
I/T3-20/1
1
17.66
20%
I/T3-20/2
1.1
I/T3-20/3
1.1
Volume
I/T3-30/1
1.2
30%
I/T3-30/2
1.1
I/T3-30/3
1.1
18.89
Volume
I/T3-40/1
1.1
24.35
40%
I/T3-40/2
1.1
I/T3-40/3
1.3
0.867
0.767
0.600
0.967
1.067
11.13
11.19
7.70
17.72
18.19
3.761
7.016
7.289
9.254
12.047
9.716
18.619
17.757
17.42
25.65
1.133
1.167
19.60
18.45
27.11
21.379
23.307
Volume
I/T3-50/1
1
21.53
50%
I/T3-50/2
1.1
I/T3-50/3
1.1
24.24
Volume
I/T4-20/1
1.4
27.37
20%
I/T4-20/2
1.4
I/T4-20/3
1.5
30.98
Volume
I/T4-30/1
1.1
29.70
30%
I/T4-30/2
1.1
I/T4-30/3
1.2
Volume
I/T4-40/1
1.2
40%
I/T4-40/2
1.3
I/T4-40/3
1.3
32.61
Volume
I/T4-50/1
1.5
42.39
50%
I/T4-50/2
1.6
I/T4-50/3
1.4
28.04
Volume
I/T5-20/1
1.7
50.39
20%
I/T5-20/2
1.7
1.067
1.433
1.133
24.49
29.77
25.89
23.421
29.375
28.023
28.48
30.89
1.267
1.500
1.667
33.05
37.30
48.65
I/T5-20/3
1.6
42.00
Volume
I/T5-30/1
1.6
47.06
30%
I/T5-30/2
1.7
I/T5-30/3
1.6
42.85
Volume
I/T5-40/1
1.7
47.74
40%
I/T5-40/2
1.8
I/T5-40/3
1.7
50.83
Volume
I/T5-50/1
1.8
50.49
50%
I/T5-50/2
1.7
I/T5-50/3
1.6
1.633
1.733
1.700
45.82
48.20
47.18
32.180
35.908
47.014
45.242
48.920
48.555
48.00
Jenis
komposit
No
Spesimen
Harga
impak
(J/mm²)
Harga
impak
rata-rata
(j/mm²)
Energi
yang
terserap
(J)
Volume
I/T1-20/1
0.5
20%
I/T1-20/2
0.6
I/T1-20/3
0.4
3.03
Volume
I/T1-30/1
0.5
3.44
30%
I/T1-30/2
0.5
I/T1-30/3
0.6
Energi
yang
terserap
rata-rata
(J)
3.12
0.500
0.533
3.41
4.42
5.18
3.188
4.343
Volume
I/T1-40/1
0.7
8.65
40%
I/T1-40/2
0.6
I/T1-40/3
0.7
7.37
Volume
I/T1-50/1
0.8
7.10
50%
I/T1-50/2
0.7
I/T1-50/3
0.8
6.94
Volume
I/T2-20/1
0.8
8.06
20%
I/T2-20/2
0.8
I/T2-20/3
0.9
Volume
I/T2-30/1
0.9
30%
I/T2-30/2
0.8
I/T2-30/3
0.7
10.85
Volume
I/T2-40/1
0.8
12.27
40%
I/T2-40/2
0.7
I/T2-40/3
0.6
10.71
Volume
I/T2-50/1
0.9
16.77
50%
I/T2-50/2
1
0.700
0.767
0.833
6.26
8.70
8.90
7.428
7.578
8.869
9.64
14.11
0.800
0.700
1.000
12.79
10.78
19.69
I/T2-50/3
1.1
21.45
Volume
I/T3-20/1
1.1
19.42
20%
I/T3-20/2
1.1
I/T3-20/3
1.2
19.01
Volume
I/T3-30/1
1.3
27.78
30%
I/T3-30/2
1.1
I/T3-30/3
1.3
22.32
Volume
I/T3-40/1
1.1
24.35
40%
I/T3-40/2
1
1.133
1.233
1.067
18.19
19.60
16.78
I/T3-40/3
1.1
22.94
Volume
I/T3-50/1
1.4
30.15
50%
I/T3-50/2
1.4
I/T3-50/3
1.5
33.06
Volume
I/T4-20/1
1.5
29.33
20%
I/T4-20/2
1.4
I/T4-20/3
1.5
30.98
Volume
I/T4-30/1
1.1
29.70
30%
I/T4-30/2
1.3
I/T4-30/3
1.3
30.85
Volume
I/T4-40/1
1.4
36.04
40%
I/T4-40/2
1.6
I/T4-40/3
1.6
40.13
Volume
I/T4-50/1
1.7
48.05
50%
I/T4-50/2
1.5
1.433
1.467
1.233
1.533
1.567
31.16
29.77
30.60
40.67
34.97
12.586
11.254
19.304
18.873
23.236
21.357
31.457
30.026
30.384
38.947
37.683
I/T4-50/3
1.5
30.04
Volume
I/T5-20/1
1.4
20%
I/T5-20/2
1.5
I/T5-20/3
1.5
39.38
Volume
I/T5-30/1
1.5
44.12
30%
I/T5-30/2
1.7
I/T5-30/3
1.7
45.53
Volume
I/T5-40/1
1.8
50.54
40%
I/T5-40/2
1.7
41.50
1.467
1.633
1.767
42.93
45.82
45.52
I/T5-40/3
1.8
53.82
Volume
I/T5-50/1
1.8
50.49
50%
I/T5-50/2
1.7
I/T5-50/3
1.8
1.767
47.18
41.267
45.155
49.961
50.555
54.00
Jenis
komposit
No
Spesimen
Harga
impak
(J/mm²)
Harga
impak
rata-rata
(j/mm²)
Energi
yang
terserap
(J)
Volume
I/T1-20/1
0.6
20%
I/T1-20/2
0.5
I/T1-20/3
0.5
3.03
Volume
I/T1-30/1
0.6
4.13
30%
I/T1-30/2
0.5
I/T1-30/3
0.4
3.45
Volume
I/T1-40/1
0.5
6.18
40%
I/T1-40/2
0.6
3.74
0.533
0.500
0.600
2.84
4.42
5.09
I/T1-40/3
0.6
5.73
Volume
I/T1-50/1
0.6
5.32
50%
I/T1-50/2
0.8
I/T1-50/3
0.7
6.07
Volume
I/T2-20/1
0.9
9.07
20%
I/T2-20/2
0.8
I/T2-20/3
1
10.71
Volume
I/T2-30/1
0.7
10.98
30%
I/T2-30/2
0.8
I/T2-30/3
0.7
10.85
I/T2-40/1
0.7
10.74
Volume
Energi
yang
terserap
rata-rata
(J)
0.700
0.900
0.733
9.49
8.90
12.79
3.206
3.998
5.669
6.962
9.562
11.541
40%
I/T2-40/2
0.8
0.800
12.32
I/T2-40/3
0.9
14.46
Volume
I/T2-50/1
1.1
16.46
50%
I/T2-50/2
1.1
I/T2-50/3
1.2
15.97
Volume
I/T3-20/1
1
17.66
20%
I/T3-20/2
1.1
I/T3-20/3
0.9
14.26
Volume
I/T3-30/1
1.2
25.65
30%
I/T3-30/2
1.3
I/T3-30/3
1.3
22.32
Volume
I/T3-40/1
1.3
28.78
40%
I/T3-40/2
1.3
I/T3-40/3
1.2
25.03
Volume
I/T3-50/1
1.4
30.15
50%
I/T3-50/2
1.3
I/T3-50/3
1.3
Volume
I/T4-20/1
1.3
20%
I/T4-20/2
1.2
I/T4-20/3
1.2
24.79
Volume
I/T4-30/1
1.3
35.10
30%
I/T4-30/2
1.2
I/T4-30/3
1.3
30.85
Volume
I/T4-40/1
1.6
41.18
40%
I/T4-40/2
1.5
I/T4-40/3
1.5
Volume
I/T4-50/1
1.8
50%
I/T4-50/2
1.7
I/T4-50/3
1.7
34.04
Volume
I/T5-20/1
1.7
50.39
20%
I/T5-20/2
1.5
I/T5-20/3
1.5
39.38
Volume
I/T5-30/1
1.6
47.06
30%
I/T5-30/2
1.7
1.133
1.000
1.267
1.267
1.333
14.73
18.19
23.17
21.81
28.94
12.506
15.720
16.701
23.711
25.206
29.245
28.65
25.42
1.233
1.267
1.533
25.52
28.25
38.13
25.240
31.399
38.979
37.62
50.87
1.733
1.567
1.667
39.63
42.93
45.82
I/T5-30/3
1.7
45.53
Volume
I/T5-40/1
1.7
47.74
40%
I/T5-40/2
1.6
I/T5-40/3
1.8
53.82
Volume
I/T5-50/1
1.8
50.49
50%
I/T5-50/2
1.8
I/T5-50/3
1.9
1.700
1.833
42.84
53.95
53.68
41.514
44.231
46.135
48.132
52.704
Jenis
komposit
No
Spesimen
Harga
impak
(J/mm²)
Volume
I/T1-20/1
0.4
20%
I/T1-20/2
0.6
Harga
impak
rata-rata
(j/mm²)
Energi
yang
terserap
(J)
Energi
yang
terserap
rata-rata
(J)
3.15
0.533
3.64
I/T1-20/3
0.6
3.03
Volume
I/T1-30/1
0.4
2.75
30%
I/T1-30/2
0.6
I/T1-30/3
0.6
5.18
Volume
I/T1-40/1
0.6
7.42
40%
I/T1-40/2
0.7
I/T1-40/3
0.5
4.78
Volume
I/T1-50/1
0.8
7.10
50%
I/T1-50/2
0.9
I/T1-50/3
0.7
6.07
Volume
I/T2-20/1
0.7
7.06
20%
I/T2-20/2
0.9
I/T2-20/3
0.9
9.64
Volume
I/T2-30/1
0.8
12.55
30%
I/T2-30/2
1.1
I/T2-30/3
1
Volume
I/T2-40/1
0.9
40%
I/T2-40/2
0.8
I/T2-40/3
0.6
9.64
Volume
I/T2-50/1
1
14.96
50%
I/T2-50/2
0.9
I/T2-50/3
0.9
11.98
Volume
I/T3-20/1
1.1
19.42
20%
I/T3-20/2
1.1
0.533
0.667
0.800
0.833
0.967
5.30
5.94
10.68
10.02
17.59
3.273
4.409
6.045
7.949
8.904
15.213
15.50
13.81
0.767
0.933
1.133
12.32
12.05
18.19
I/T3-20/3
1.2
19.01
Volume
I/T3-30/1
1.1
23.51
30%
I/T3-30/2
1.2
I/T3-30/3
1.2
20.60
Volume
I/T3-40/1
1.2
26.57
40%
I/T3-40/2
1.3
I/T3-40/3
1.2
25.03
Volume
I/T3-50/1
1.4
30.15
50%
I/T3-50/2
1.3
1.167
1.233
1.367
21.38
21.81
28.94
11.922
12.997
18.873
21.833
24.468
29.980
I/T3-50/3
1.4
30.86
Volume
I/T4-20/1
1.2
20%
I/T4-20/2
1.1
I/T4-20/3
1.1
22.72
Volume
I/T4-30/1
1.4
37.80
30%
I/T4-30/2
1.5
I/T4-30/3
1.4
33.22
Volume
I/T4-40/1
1.5
38.61
40%
I/T4-40/2
1.4
23.46
1.133
1.433
1.433
23.39
35.31
35.59
I/T4-40/3
1.4
35.12
Volume
I/T4-50/1
1.8
50.87
50%
I/T4-50/2
1.6
I/T4-50/3
1.7
34.04
Volume
I/T5-20/1
1.6
47.42
20%
I/T5-20/2
1.7
I/T5-20/3
1.6
42.00
Volume
I/T5-30/1
1.7
50.01
30%
I/T5-30/2
1.6
I/T5-30/3
1.5
40.17
Volume
I/T5-40/1
1.8
50.54
40%
I/T5-40/2
1.7
I/T5-40/3
1.5
44.85
Volume
I/T5-50/1
1.9
48.45
50%
I/T5-50/2
1.7
I/T5-50/3
1.6
1.700
1.633
1.600
1.667
1.733
37.30
48.65
43.12
45.52
48.64
45.76
23.191
35.444
36.438
40.737
46.026
44.432
46.971
47.617
Data Hasil Pengujian tarik Serat Rami Alkali 2 jam
specimen
20% T1
30% T1
40% T1
50% T1
20% T2
30% T2
40% T2
50% T2
20% T3
30% T3
40% T3
50% T3
20% T4
kek tarik
Mod Elastisitas
kek tarik rata2
Mod Elastisitas rata2
0.748
1.048
0.662
0.797
0.813
0.650
0.425
0.694
0.148
0.260
0.772
0.850
0.960
1.182
1.209
1.107
1.117
1.814
0.906
1.174
0.894
0.801
0.707
0.907
2.423
2.937
1.506
1.747
0.848
1.163
1.247
1.142
1.289
3.106
1.348
3.297
1.439
3.370
1.314
3.414
2.062
4.774
1.994
4.060
1.894
3.962
2.025
3.444
3.805
6.300
2.523
4.875
1.752
3.504
2.010
4.821
2.685
5.173
3.192
5.565
4.215
5.650
2.678
5.872
2.867
4.952
2.193
5.924
2.032
6.432
1.680
6.389
3.503
4.462
3.032
6.756
3.162
7.731
2.430
8.074
2.790
5.158
4.686
28.560
5.136
6.644
6.132
73.879
7.120
11.055
5.941
9.449
6.381
7.403
4.322
9.890
4.872
5.685
4.353
5.208
3.436
3.878
4.752
6.061
30% T4
40% T4
50% T4
20% T5
30% T5
40% T5
50% T5
4.030
5.114
3.666
6.702
3.446
5.881
6.399
5.011
5.808
4.520
5.847
4.816
14.612
9.880
7.538
8.615
12.980
8.711
6.933
4.352
9.011
6.506
9.254
6.795
6.324
4.241
12.679
8.325
6.129
3.819
7.351
5.148
11.556
7.756
9.362
6.119
11.162
6.652
9.940
6.098
16.830
13.442
3.714
5.899
6.018
4.782
11.710
9.069
8.399
5.884
8.377
5.462
9.423
6.341
12.644
8.731
Spesimen
20% T1
30% T1
40% T1
50% T1
20% T2
30% T2
kek tarik
Mod Elastisitas
kek tarik rata2
0.617
0.331
0.798
0.878
0.676
0.793
1.103
1.511
0.604
0.829
0.755
0.956
0.790
1.013
0.872
1.026
1.755
1.877
1.868
1.498
1.829
1.541
2.019
1.077
1.437
2.525
1.483
2.025
1.320
1.693
1.690
1.858
3.080
5.082
1.806
3.308
1.721
4.401
0.618
0.442
2.574
2.579
1.663
1.563
1.014
0.839
40% T2
50% T2
20% T3
30% T3
40% T3
50% T3
20% T4
30% T4
40% T4
50% T4
20% T5
30% T5
40% T5
50% T5
1.400
1.272
4.848
5.677
2.989
5.084
2.225
4.002
4.810
6.737
4.654
6.013
4.844
8.559
1.990
6.122
2.316
7.307
4.229
7.356
3.610
5.529
4.049
5.945
3.703
6.352
2.471
7.377
2.870
5.979
4.125
4.791
8.656
8.316
7.385
9.128
6.798
12.613
3.284
9.409
3.285
6.163
5.672
9.252
3.651
6.096
4.869
8.587
6.395
7.471
6.014
8.884
4.332
7.280
4.210
11.503
8.134
6.315
6.910
10.581
5.907
9.861
2.669
4.675
2.991
8.403
3.317
9.901
3.618
9.884
4.183
9.254
5.789
10.265
5.168
10.949
4.732
6.637
5.065
9.142
10.123
8.857
9.386
13.927
9.234
13.948
3.354
4.921
4.769
7.103
2.845
6.928
3.787
5.942
3.155
6.049
7.613
10.019
4.080
8.275
4.972
7.385
4.852
9.222
6.983
8.919
2.992
7.659
4.530
9.801
4.988
8.909
9.581
12.244
Specimen
20% T1
30% T1
40% T1
50% T1
20% T2
30% T2
40% T2
50% T2
20% T3
30% T3
40% T3
50% T3
20% T4
30% T4
kek tarik
Mod Elastisitas
kek tarik rata2
0.614
0.723
0.601
0.886
0.461
0.986
0.728
0.948
1.280
1.608
1.059
1.128
1.094
0.756
0.803
1.021
1.556
2.701
1.388
1.568
1.559
1.293
1.049
0.710
2.152
3.587
2.352
3.096
2.461
3.418
2.441
2.282
1.524
2.222
1.856
2.700
2.504
4.347
1.540
1.531
1.508
2.110
1.971
5.536
2.235
12.017
2.169
2.482
7.108
8.616
4.824
7.293
4.212
7.482
3.151
5.782
5.573
4.743
5.164
5.205
4.608
5.266
5.310
5.608
2.743
3.657
2.738
5.420
2.448
6.359
3.022
6.243
3.362
7.947
3.350
7.040
3.950
6.360
2.739
6.812
5.800
5.782
4.920
6.533
4.406
6.339
4.554
7.478
5.963
9.421
6.740
9.554
7.843
9.780
6.414
9.460
3.248
8.615
3.402
7.451
3.248
6.753
3.709
6.985
4.391
7.598
5.379
9.314
5.373
9.913
40% T4
50% T4
20% T5
30% T5
40% T5
50% T5
6.374
10.432
9.054
8.731
4.735
8.456
6.023
7.682
5.104
9.453
4.647
8.886
6.319
8.414
3.189
7.593
5.604
9.499
4.016
8.420
5.970
10.473
5.554
8.679
6.049
9.804
5.747
6.949
7.312
7.939
6.337
7.343
9.015
10.398
8.512
13.404
12.746
11.112
6.604
8.290
5.357
8.917
4.270
8.504
5.858
9.652
6.465
7.410
10.091
11.638
Alkali 8 jam
20% T1
30% T1
40% T1
50% T1
20% T2
30% T2
40% T2
kek tarik
Mod Elastisitas
kek tarik rata2
0.501
1.011
0.604
0.895
0.661
0.948
0.651
0.725
1.614
2.394
1.222
1.908
0.981
1.244
1.072
2.085
1.567
1.709
1.132
1.213
0.555
0.478
1.273
1.453
2.372
3.253
1.788
3.309
1.462
3.021
1.530
3.652
0.693
0.555
1.448
2.825
1.814
4.877
1.837
3.042
2.722
4.923
2.262
4.441
2.008
4.131
2.057
4.268
4.583
7.716
3.663
6.784
50% T2
20% T3
30% T3
40% T3
50% T3
20% T4
30% T4
40% T4
50% T4
20% T5
30% T5
40% T5
50% T5
3.410
7.462
2.996
5.174
3.718
7.497
4.319
8.370
3.317
4.892
2.061
5.956
3.508
7.480
2.482
3.236
3.683
4.884
3.405
6.069
2.834
6.017
4.320
5.510
3.759
6.712
4.736
8.472
7.344
9.044
8.260
9.177
7.649
9.732
3.360
7.088
3.061
6.363
3.548
9.004
3.471
7.277
4.363
7.497
4.560
8.014
6.801
10.864
5.525
8.868
4.815
10.747
8.967
8.467
13.715
9.053
7.504
8.595
6.487
13.079
4.690
11.412
5.858
12.029
4.953
11.008
6.546
12.282
6.780
10.970
8.913
11.058
7.580
10.456
7.301
11.852
6.599
8.846
7.585
10.638
7.338
12.190
3.785
6.919
2.684
5.557
3.307
5.657
4.272
6.898
7.751
9.318
3.323
7.485
4.131
7.596
5.713
10.160
10.062
8.705
5.679
12.173
6.093
11.420
7.931
11.122
7.174
10.558
Data Pengujian Bending komposit serat rami
Tabel data hasil pengujian bending komposit serat rami pada alkali 2 jam tebal 1mm
Jenis
No
Spesimen
Komposit
Defleksi
Support
span
Beban
Momen
Bending
Teg Bending
Modulus
elastisitas
Kekakuan
(mm)
(mm)
(N)
(Nmm)
(MPa)
(MPa)
(Nmm2)
Volume
B/T1-20/1
2.16
25.4
31.89
202.5015
55.55596708
2048.610409
5040.3498
20%
B/T1-20/2
2.456
25.4
35.42
224.917
56.74080381
1840.134364
4923.5699
B/T1-20/3
2.512
25.4
33.52
212.852
55.61486707
1763.411557
4555.5864
Volume
B/T1-30/1
4.024
25.4
33.53
212.9155
44.49664096
767.1031041
2844.6936
30%
B/T1-30/2
3.668
25.4
42.98
272.923
39.02802803
635.6103478
4000.3408
B/T1-30/3
2.945
25.4
31.51
200.0885
32.58107063
699.7571
3652.7758
Volume
B/T1-40/1
5.898
25.4
36.35
230.8225
20.61436673
163.4005735
2104.067
40%
B/T1-40/2
3.267
25.4
30.92
196.342
17.96923781
262.8537556
3231.099
B/T1-40/3
4.351
25.4
29.85
189.5475
16.16448967
173.6845796
2342.1525
Volume
B/T1-50/1
1.309
25.4
95.37
605.5995
73.7389425
3188.011214
24873.222
50%
B/T1-50/2
1.458
25.4
90.53
574.8655
69.50847522
2628.825805
21198.001
B/T1-50/3
1.422
25.4
97.36
618.236
79.65419056
3170.090161
23374.422
Jenis
No
Spesimen
Komposit
Volume
20%
Volume
30%
Volume
40%
Volume
50%
Defleksi
Support
span
Beban
Momen
Bending
Teg Bending
Modulus
elastisitas
Kekakuan
(mm)
(mm)
(N)
(Nmm)
(MPa)
(MPa)
(Nmm2)
B/T2-20/1
1.408
30
136.21
1021.575
111.6383903
5663.473534
54416.282
B/T2-20/2
2.203
30
115.02
862.65
92.05282113
2984.657971
29368.475
B/T2-20/3
1.945
30
127.48
956.1
99.28134127
3561.236609
36867.609
B/T2-30/1
1.601
30
95.02
712.65
42.94452033
1436.976454
33384.603
B/T2-30/2
2.663
30
100.22
751.65
41.74702685
825.0889746
21169.264
B/T2-30/3
1.418
30
42.19
316.425
18.69976755
706.4691549
16736.16
B/T2-40/1
1.104
30
92.44
693.3
43.82917915
2165.473278
47099.185
B/T2-40/2
1.177
30
64.33
482.475
29.10951199
1349.015771
30743.946
B/T2-40/3
0.803
30
58.17
436.275
28.72592593
1987.403205
40747.976
B/T2-50/1
1.253
30
228.18
1711.35
69.31489095
2476.976723
102435.16
B/T2-50/2
2.515
30
205.07
1538.025
61.77784138
1067.989305
45865.557
B/T2-50/3
2.061
30
302.28
2267.1
92.18383093
2033.078182
82500
Jenis
No
Spesimen
Komposit
Volume
20%
Volume
30%
Volume
40%
Volume
50%
Defleksi
Support
span
Beban
Momen
Bending
Teg Bending
Modulus
elastisitas
Kekakuan
(mm)
(mm)
(N)
(Nmm)
(MPa)
(MPa)
(Nmm2)
B/T3-20/1
2.284
50
103.94
1299.25
55.91734519
3238.386266
118510.11
B/T3-20/2
4.057
50
116.27
1453.375
56.58384811
1816.043519
74633.093
B/T3-20/3
1.589
50
67.42
842.75
41.94233706
3491.458894
110492.71
B/T3-30/1
2.997
50
140.44
1755.5
42.04763143
1313.661709
122031.75
B/T3-30/2
2.021
50
148.98
1862.25
45.43606176
2178.485484
191968.7
B/T3-30/3
1.621
50
86.68
1083.5
31.49892436
1927.756502
139253.03
B/T3-40/1
2.391
50
373.12
4664
176.9332114
8685.407299
406385.06
B/T3-40/2
2.396
50
346.69
4333.625
140.6906907
6612.498434
376810.74
B/T3-40/3
1.991
50
298.23
3727.875
114.2544453
6462.326264
390075.65
B/T3-50/1
3.318
50
204.37
2554.625
57.56090691
1606.303075
160401.91
B/T3-50/2
3.804
50
168.34
2104.25
54.01745604
1408.747268
115243.27
B/T3-50/3
1.371
50
49.73
621.625
13.40411998
885.5881125
94460.4
Jenis
No
Spesimen
Komposit
Volume
20%
Volume
30%
Volume
40%
Volume
50%
Defleksi
Support
span
Beban
Momen
Bending
Teg Bending
Modulus
elastisitas
Kekakuan
(mm)
(mm)
(N)
(Nmm)
(MPa)
(MPa)
(Nmm2)
B/T4-20/1
6.888
65
163.21
2652.1625
59.13317899
1373.918196
135566.52
B/T4-20/2
6.897
65
163.72
2660.45
68.24309628
1639.400375
135812.69
B/T4-20/3
7.279
65
188.65
3065.5625
75.83333333
1746.685035
148280.46
B/T4-30/1
6.424
65
222.3
3612.375
77.25820997
1801.842035
197985.22
B/T4-30/2
7.386
65
150.87
2451.6375
52.26851983
1083.299467
116867.14
B/T4-30/3
6.645
65
177.56
2885.35
61.9531668
1396.838287
152879.4
B/T4-40/1
25.6
65
114.29
1857.2125
29.38254474
151.0675277
25542.717
B/T4-40/2
15.276
65
138.43
2249.4875
31.33818412
265.0593562
51846.495
B/T4-40/3
16.03
65
109.69
1782.4625
26.40340474
208.9820045
39150.052
B/T4-50/1
3.912
65
216.27
3514.3875
59.77709379
2089.316262
316297.87
B/T4-50/2
5.56
65
459.11
7460.5375
128.893856
3109.378448
472433.62
B/T4-50/3
5.02
65
470.19
7640.5875
146.7435966
4076.050225
535881.18
Jenis
No
Spesimen
Komposit
Volume
20%
Volume
30%
Volume
40%
Volume
50%
Defleksi
Support
span
Beban
Momen
Bending
Teg Bending
Modulus
elastisitas
Kekakuan
(mm)
(mm)
(N)
(Nmm)
(MPa)
(MPa)
(Nmm2)
B/T5-20/1
12.038
80
242.78
4855.6
71.36390359
1171.006276
215123.22
B/T5-20/2
5.406
80
120.54
2410.8
37.4607162
1356.226594
237839.44
B/T5-20/3
8.947
80
258
5160
67.68439201
1453.941173
307589.14
B/T5-30/1
11.38
80
152.95
3059
51.62052418
921.6150717
143362.62
B/T5-30/2
14.523
80
210.32
4206.4
67.35520648
916.1145868
154473.13
B/T5-30/3
11.19
80
205.37
4107.4
71.53023129
1298.760175
195765.27
B/T5-40/1
4.915
80
252.177
5043.54
66.40589268
2382.080566
547281.38
B/T5-40/2
3.194
80
198.111
3962.22
55.13293135
3287.886892
661610.52
B/T5-40/3
5.514
80
285.393
5707.86
80.92429112
2722.532174
552084.15
B/T5-50/1
3.415
80
353.189
7063.78
65.59440982
2906.134616
1103177
B/T5-50/2
4.715
80
295.63
5912.6
58.38643845
1886.952513
668798.87
B/T5-50/3
5.171
80
289.74
5794.8
57.18025971
1734.568266
597671.63
Jenis
No
Spesimen
Komposit
Defleksi
Support
span
Beban
Momen
Bending
Teg Bending
Modulus
elastisitas
Kekakuan
(mm)
(mm)
(N)
(Nmm)
(MPa)
(MPa)
(Nmm2)
Volume
B/T1-20/1
1.922
25.4
36.24
230.124
63.13415638
2616.335371
6437.1661
20%
B/T1-20/2
2.557
25.4
38.27
243.0145
61.30633997
1909.664503
5109.6087
B/T1-20/3
2.29
25.4
38.67
245.5545
64.15951401
2231.557068
5764.9906
Volume
B/T1-30/1
2.37
25.4
31.42
199.517
41.69652428
1220.494969
4526.0333
30%
B/T1-30/2
2.301
25.4
31.62
200.787
28.71256971
745.4167059
4691.4291
B/T1-30/3
2.028
25.4
28.35
180.0225
29.31365764
914.2591641
4772.49
Volume
B/T1-40/1
3.013
25.4
39.06
248.031
22.15122873
343.7059392
4425.8126
40%
B/T1-40/2
3.004
25.4
68.6
435.61
39.86706707
634.2318141
7796.2203
B/T1-40/3
2.18
25.4
77.13
489.7755
41.76774166
895.7211877
12078.882
Volume
B/T1-50/1
6.988
25.4
87.11
553.1485
67.35240936
545.4598915
4255.7394
50%
B/T1-50/2
2.591
25.4
74.03
470.0905
56.83985883
1209.670666
9754.393
B/T1-50/3
2.701
25.4
52.86
335.661
43.24692392
906.1356559
6681.3233
Jenis
No
Spesimen
Komposit
Volume
20%
Volume
30%
Volume
40%
Volume
50%
Defleksi
Support
span
Beban
Momen
Bending
Teg Bending
Modulus
elastisitas
Kekakuan
(mm)
(mm)
(N)
(Nmm)
(MPa)
(MPa)
(Nmm2)
B/T2-20/1
1.848
30
59.69
447.675
48.92221949
1890.933035
18168.628
B/T2-20/2
3.448
30
68.35
512.625
54.70188075
1133.201043
11150.486
B/T2-20/3
3.249
30
101.95
764.625
79.39859383
1704.966691
17650.623
B/T2-30/1
3.748
30
80.83
606.225
36.53131528
522.154415
12130.97
B/T2-30/2
2.365
30
100.98
757.35
42.06360777
936.0989824
24017.442
B/T2-30/3
1.902
30
74.95
562.125
33.21989993
935.6664018
22165.812
B/T2-40/1
1.421
30
222.85
1671.375
105.6613217
4055.83731
88214.726
B/T2-40/2
1.512
30
186.09
1395.675
84.20626591
3037.74408
69229.911
B/T2-40/3
2.157
30
341.92
2564.4
168.8493827
4348.87402
89165.508
B/T2-50/1
1.859
30
304.98
2287.35
92.64464651
2231.451186
92281.469
B/T2-50/2
2.072
30
321.72
2412.9
96.9189405
2033.719584
87339.527
B/T2-50/3
2.225
30
355.54
2666.55
108.4260925
2215.037641
89883.708
Jenis
No
Spesimen
Komposit
Volume
20%
Volume
30%
Volume
40%
Volume
50%
Defleksi
Support
span
Beban
Momen
Bending
Teg Bending
Modulus
elastisitas
Kekakuan
(mm)
(mm)
(N)
(Nmm)
(MPa)
(MPa)
(Nmm2)
B/T3-20/1
4.806
50
146.74
1834.25
78.9427673
2172.73512
79512.155
B/T3-20/2
2.074
50
129.85
1623.125
63.19267805
3967.315954
163042.93
B/T3-20/3
0.893
50
50.95
636.875
31.69626332
4694.991516
148580.39
B/T3-30/1
0.903
50
86.91
1086.375
26.02078929
2698.121253
250640.23
B/T3-30/2
1.375
50
85.42
1067.75
26.05147265
1835.90364
161780.3
B/T3-30/3
1.533
50
138.04
1725.5
50.16280016
3246.228487
234493.91
B/T3-40/1
1.901
50
87.58
1094.75
41.53036732
2564.153739
119975.23
B/T3-40/2
3.489
50
172.66
2158.25
70.06736466
2261.52737
128872.29
B/T3-40/3
1.251
50
69.1
863.75
26.47279674
2383.030219
143843.26
B/T3-50/1
0.777
50
186.51
2331.375
52.53062949
6259.906274
625100.55
B/T3-50/2
1.854
50
264.48
3306
84.86715441
4541.186924
371494.07
B/T3-50/3
1.482
50
236.11
2951.375
63.64059456
3889.707564
414891.9
Jenis
No
Spesimen
Komposit
Volume
20%
Volume
30%
Volume
40%
Volume
50%
Defleksi
Support
span
Beban
Momen
Bending
Teg Bending
Modulus
elastisitas
Kekakuan
(mm)
(mm)
(N)
(Nmm)
(MPa)
(MPa)
(Nmm2)
B/T4-20/1
3.772
65
137.26
2230.475
49.73114484
2109.98593
208195.41
B/T4-20/2
2.188
65
95.82
1557.075
39.9404684
3024.491504
250557.66
B/T4-20/3
4.607
65
135.74
2205.775
54.56462585
1985.725175
168573.17
B/T4-30/1
3.598
65
213.36
3467.1
58.9727689
2241.086369
339274.08
B/T4-30/2
5.242
65
270.81
4400.6625
76.02915452
1945.356963
295574.19
B/T4-30/3
3.665
65
217.39
3532.5875
67.84616954
2581.281918
339362.94
B/T4-40/1
3.366
65
290.53
4721.1125
74.69166789
2920.651418
493827.99
B/T4-40/2
4.4
65
324.33
5270.3625
73.42276425
2156.040999
421728.82
B/T4-40/3
2.082
65
227
3688.75
54.64101446
3329.81809
623797.98
B/T4-50/1
3.327
65
222.3
3612.375
77.25820997
3479.120298
382283.45
B/T4-50/2
2.678
65
311.87
5067.8875
108.0465519
6176.15192
666287.8
B/T4-50/3
2.152
65
226.63
3682.7375
79.07437594
5505.174773
602523.46
Jenis
No
Spesimen
Komposit
Volume
20%
Volume
30%
Volume
40%
Volume
50%
Defleksi
Support
span
Beban
Momen
Bending
Teg Bending
Modulus
elastisitas
Kekakuan
(mm)
(mm)
(N)
(Nmm)
(MPa)
(MPa)
(Nmm2)
B/T5-20/1
4.921
80
102.43
2048.6
30.10875955
1208.577382
222025.33
B/T5-20/2
4.929
80
107.22
2144.4
33.32120451
1323.104344
232030.84
B/T5-20/3
9.253
80
170.22
3404.4
44.65595817
927.5398784
196226.09
B/T5-30/1
7.774
80
186.52
3730.4
62.95037705
1645.217118
255923.16
B/T5-30/2
5.365
80
251.82
5036.4
80.64562617
2969.24515
500667.29
B/T5-30/3
7.899
80
191.89
3837.8
66.83515646
1719.104493
259124.78
B/T5-40/1
2.87
80
306.15
6123
56.85830693
2997.447833
1137839.7
B/T5-40/2
3.851
80
324.51
6490.2
64.09019092
2535.99697
898841.86
B/T5-40/3
2.012
80
363.2
7264
71.67760864
5588.243764
1925513.6
B/T5-50/1
3.696
80
395.77
7915.4
104.2183076
4971.476635
1142193.4
B/T5-50/2
4.579
80
430.72
8614.4
119.8664193
4986.175784
1003351.5
B/T5-50/3
4.303
80
335.82
6716.4
95.22306238
4105.175016
832461.07
Jenis
No
Spesimen
Komposit
Defleksi
Support
span
Beban
Momen
Bending
Teg Bending
Modulus
elastisitas
Kekakuan
(mm)
(mm)
(N)
(Nmm)
(MPa)
(MPa)
(Nmm2)
Volume
B/T1-20/1
5.579
25.4
26.87
170.6245
46.81056241
668.2976162
1644.2627
20%
B/T1-20/2
2.763
25.4
18.27
116.0145
29.26748971
843.6979693
2257.4471
B/T1-20/3
2.777
25.4
17.53
111.3155
29.08498269
834.2099091
2155.0927
Volume
B/T1-30/1
4.705
25.4
22.68
144.018
30.09793669
443.7737212
1645.6722
30%
B/T1-30/2
5.722
25.4
28.86
183.261
26.20634921
273.591341
1721.9018
B/T1-30/3
4.661
25.4
33.59
213.2965
34.73177285
471.3191769
2460.3156
Volume
B/T1-40/1
2.977
25.4
81.2
515.62
46.04914934
723.1545517
9311.8743
40%
B/T1-40/2
3.449
25.4
72.81
462.3435
42.31371943
586.3024007
7207.0536
B/T1-40/3
3.625
25.4
90.62
575.437
49.07289964
632.8809981
8534.4583
Volume
B/T1-50/1
2.164
25.4
70.73
449.1355
54.68758942
1430.191215
11158.513
50%
B/T1-50/2
1.71
25.4
38.32
243.332
29.4219018
948.7596425
7650.4909
B/T1-50/3
3.405
25.4
88.43
561.5305
72.348193
1202.466965
8866.3
Jenis
No
Spesimen
Komposit
Volume
20%
Volume
30%
Volume
40%
Volume
50%
Defleksi
Support
span
Beban
Momen
Bending
Teg Bending
Modulus
elastisitas
Kekakuan
(mm)
(mm)
(N)
(Nmm)
(MPa)
(MPa)
(Nmm2)
B/T2-20/1
4.281
30
110.79
830.925
90.80403246
1515.067115
14557.2
B/T2-20/2
4.237
30
92.56
694.2
74.07763105
1248.822129
12288.176
B/T2-20/3
2.244
30
118.08
885.6
91.96062737
2859.116632
29598.93
B/T2-30/1
1.052
30
240.42
1803.15
108.6584043
5533.256602
128551.57
B/T2-30/2
1.512
30
308.59
2314.425
128.5443526
4474.531905
114802.83
B/T2-30/3
1.246
30
280.01
2100.075
124.1081278
5335.994947
126409.01
B/T2-40/1
1.163
30
280.99
2107.425
133.2276185
6248.461742
135904.45
B/T2-40/2
1.563
30
189.77
1423.275
85.8714766
2996.736228
68295.345
B/T2-40/3
0.931
30
160.13
1200.975
79.07654321
4718.733931
96748.792
B/T2-50/1
1.875
30
393.88
2954.1
119.6500537
2857.314714
118164
B/T2-50/2
1.508
30
349.33
2619.975
105.2365208
3034.151794
130303.8
B/T2-50/3
0.92
30
264.59
1984.425
80.68982343
3986.651355
161773.78
Jenis
No
Spesimen
Komposit
Volume
20%
Volume
30%
Volume
40%
Volume
50%
Defleksi
Support
span
Beban
Momen
Bending
Teg Bending
Modulus
elastisitas
Kekakuan
(mm)
(mm)
(N)
(Nmm)
(MPa)
(MPa)
(Nmm2)
B/T3-20/1
2.918
50
126.89
1586.125
68.26392083
3094.454818
113242.87
B/T3-20/2
3.79
50
112.36
1404.5
54.68101121
1878.60774
77204.266
B/T3-20/3
2.244
50
113.75
1421.875
70.76447406
4171.292409
132007.11
B/T3-30/1
3.453
50
131.37
1642.125
39.33208018
1066.544756
99075.985
B/T3-30/2
3.065
50
126.46
1580.75
38.56789079
1219.314427
107446.3
B/T3-30/3
2.401
50
85.02
1062.75
30.89569161
1276.57175
92214.182
B/T3-40/1
2.844
50
411.47
5143.375
195.1187513
8052.483085
376770.91
B/T3-40/2
2.94
50
218.27
2728.375
88.57641425
3392.796403
193337.23
B/T3-40/3
2.53
50
224.7
2808.75
86.08447798
3831.698802
231287.06
B/T3-50/1
2.087
50
232.97
2912.125
65.61611041
2911.147953
290700.87
B/T3-50/2
1.788
50
191.9
2398.75
61.57746117
3416.596821
279496.41
B/T3-50/3
1.987
50
125.58
1569.75
33.84857001
1543.026503
164585.43
Jenis
No
Spesimen
Komposit
Volume
20%
Volume
30%
Volume
40%
Volume
50%
Defleksi
Support
span
Beban
Momen
Bending
Teg Bending
Modulus
elastisitas
Kekakuan
(mm)
(mm)
(N)
(Nmm)
(MPa)
(MPa)
(Nmm2)
B/T4-20/1
2.099
65
116.07
1886.1375
42.05372272
3206.378552
316378.07
B/T4-20/2
2.229
65
127.6
2073.5
53.18726537
3953.521691
327521.22
B/T4-20/3
4.263
65
175.63
2853.9875
70.5995671
2776.597178
235712.28
B/T4-30/1
3.311
65
108.46
1762.475
37.69422156
1705.6629
187417.12
B/T4-30/2
3.447
65
246.52
4005.95
85.40621402
3792.851316
409175.58
B/T4-30/3
4.819
65
219.54
3567.525
76.6005758
2381.511664
260648.7
B/T4-40/1
4.197
65
198.74
3229.525
51.09359473
1602.319694
270922.55
B/T4-40/2
4.188
65
206.2
3350.75
46.6801529
1440.139484
281696.09
B/T4-40/3
4.493
65
101.09
1642.7125
24.33330463
687.1430438
128727.29
B/T4-50/1
2.486
65
291.09
4730.2125
80.45736454
4425.200087
669923.16
B/T4-50/2
3.021
65
351.39
5710.0875
98.65176547
4379.96153
665483.83
B/T4-50/3
4.542
65
210.13
3414.6125
65.58036527
2013.310628
264691.36
Jenis
No
Spesimen
Komposit
Volume
20%
Volume
30%
Volume
40%
Volume
50%
Defleksi
Support
span
Beban
Momen
Bending
Teg Bending
Modulus
elastisitas
Kekakuan
(mm)
(mm)
(N)
(Nmm)
(MPa)
(MPa)
(Nmm2)
B/T5-20/1
10.054
80
91.67
1833.4
26.94591417
529.4061779
97256.15
B/T5-20/2
11.793
80
139.05
2781
43.21314575
717.1727923
125769.52
B/T5-20/3
5.71
80
83.34
1666.8
21.86363267
735.9053403
155684.76
B/T5-30/1
7.825
80
131.97
2639.4
44.53978801
1156.466933
179895.21
B/T5-30/2
11.947
80
182.6
3652
58.47784663
966.8686349
163031.17
B/T5-30/3
7.779
80
194.41
3888.2
67.71287075
1768.548097
266577.54
B/T5-40/1
7.748
80
204.74
4094.8
53.91428428
1226.839022
281865.43
B/T5-40/2
6.27
80
229.99
4599.8
64.00463822
1944.39548
391264.22
B/T5-40/3
8.619
80
224.45
4489
63.6436673
1369.806413
277773.91
B/T5-50/1
4.486
80
326.01
6520.2
60.54671449
2042.071381
775176.1
B/T5-50/2
6.104
80
442.98
8859.6
87.48782093
2184.055943
774102.23
B/T5-50/3
5.239
80
317.59
6351.8
62.67646401
1876.618095
646617.04
Jenis
No
Spesimen
Komposit
Defleksi
Support
span
Beban
Momen
Bending
Teg Bending
Modulus
elastisitas
Kekakuan
(mm)
(mm)
(N)
(Nmm)
(MPa)
(MPa)
(Nmm2)
Volume
B/T1-20/1
2.729
25.4
18.88
119.888
32.89108368
959.9686741
2361.8829
20%
B/T1-20/2
5.525
25.4
17.74
112.649
28.41846018
409.6855767
1096.1784
B/T1-20/3
4.121
25.4
25.11
159.4485
41.66137566
805.217873
2080.1948
Volume
B/T1-30/1
6.338
25.4
54.87
348.4245
72.81630449
797.0047029
2955.5794
30%
B/T1-30/2
4.446
25.4
31.45
199.7075
28.55820106
383.7117216
2414.9665
B/T1-30/3
5.834
25.4
46.45
294.9575
48.02890291
520.7190943
2718.1862
Volume
B/T1-40/1
4.212
25.4
67.18
426.593
38.09829868
422.8687252
5445.1713
40%
B/T1-40/2
2.384
25.4
53.56
340.106
31.12653225
623.9620167
7669.98
B/T1-40/3
3.33
25.4
61.6
391.16
33.35787484
468.3197661
6315.335
Volume
B/T1-50/1
2.544
25.4
115.19
731.4565
89.06352927
1981.27781
15458.152
50%
B/T1-50/2
2.024
25.4
103.78
659.003
79.68175807
2170.850775
17505.039
B/T1-50/3
1.738
25.4
79.87
507.1745
65.34490756
2127.769394
15688.948
Jenis
No
Spesimen
Komposit
Volume
20%
Volume
30%
Volume
40%
Volume
50%
Defleksi
Support
span
Beban
Momen
Bending
Teg Bending
Modulus
elastisitas
Kekakuan
(mm)
(mm)
(N)
(Nmm)
(MPa)
(MPa)
(Nmm2)
B/T2-20/1
2.143
30
74.04
555.3
60.68355053
2022.650174
19434.204
B/T2-20/2
3.155
30
92.38
692.85
73.93357343
1673.841373
16470.285
B/T2-20/3
1.765
30
63.64
477.3
49.5627907
1959.132645
20281.87
B/T2-30/1
3.37
30
133.35
1000.125
60.26785714
958.0519893
22257.975
B/T2-30/2
1.698
30
102.9
771.75
42.86339116
1328.603037
34087.898
B/T2-30/3
0.815
30
38.2
286.5
16.93128989
1112.924401
26365.031
B/T2-40/1
1.742
30
192.18
1441.35
91.11955484
2853.132914
62055.827
B/T2-40/2
1.441
30
248.15
1861.125
112.2885963
4250.404251
96866.325
B/T2-40/3
1.334
30
131.2
984
64.79012346
2698.239358
55322.339
B/T2-50/1
1.924
30
235.52
1766.4
71.54458373
1665.014981
68856.549
B/T2-50/2
2.676
30
340.86
2556.45
102.6849125
1668.371231
71649.383
B/T2-50/3
1.972
30
225.25
1689.375
68.69262908
1583.3632
64251.078
Jenis
No
Spesimen
Komposit
Volume
20%
Volume
30%
Volume
40%
Volume
50%
Defleksi
Support
span
Beban
Momen
Bending
Teg Bending
Modulus
elastisitas
Kekakuan
(mm)
(mm)
(N)
(Nmm)
(MPa)
(MPa)
(Nmm2)
B/T3-20/1
1.837
50
38.56
482
20.74439899
1493.722439
54663.4
B/T3-20/2
1.731
50
7.21
90.125
3.508811773
263.9379162
10846.933
B/T3-20/3
1.774
50
92.92
1161.5
57.80602136
4310.202436
136403.14
B/T3-30/1
2.172
50
130.45
1630.625
39.05663287
1683.696177
156405.87
B/T3-30/2
1.194
50
50.61
632.625
15.43508582
1252.636391
110382.64
B/T3-30/3
3.524
50
120.78
1509.75
43.89063318
1235.592929
89254.044
B/T3-40/1
4.77
50
180.02
2250.25
85.36534283
2100.504494
98281.359
B/T3-40/2
2.242
50
131.05
1638.125
53.18155994
2671.23747
152219.47
B/T3-40/3
2.881
50
317.77
3972.125
121.7403853
4758.591754
287235.7
B/T3-50/1
1.91
50
286.38
3579.75
80.6590621
3910.173653
390461.39
B/T3-50/2
1.959
50
503.47
6293.375
161.5549994
8181.358694
669280.14
B/T3-50/3
1.341
50
237.87
2973.375
64.11498128
4330.735585
461933.72
Jenis
No
Spesimen
Komposit
Volume
20%
Volume
30%
Volume
40%
Volume
50%
Defleksi
Support
span
Beban
Momen
Bending
Teg Bending
Modulus
elastisitas
Kekakuan
(mm)
(mm)
(N)
(Nmm)
(MPa)
(MPa)
(Nmm2)
B/T4-20/1
3.019
65
139.2
2262
50.43403294
2673.519593
263800.1
B/T4-20/2
4.228
65
111.1
1805.375
46.30960174
1814.774216
150341.17
B/T4-20/3
3.539
65
98.52
1600.95
39.60296846
1876.175022
159273.19
B/T4-30/1
6.815
65
170.63
2772.7375
59.30080237
1303.683937
143247.93
B/T4-30/2
7.163
65
200.15
3252.4375
69.3414479
1481.888698
159867.24
B/T4-30/3
4.157
65
137.99
2242.3375
48.1466405
1735.256059
189918.13
B/T4-40/1
4.483
65
257.33
4181.6125
66.15635872
1942.336786
328413.13
B/T4-40/2
3.609
65
203.27
3303.1375
46.01685101
1647.437603
322244.3
B/T4-40/3
5.257
65
226.83
3685.9875
54.60009388
1317.764769
246866.04
B/T4-50/1
5.16
65
319.87
5197.8875
88.4121653
2342.774883
354668.52
B/T4-50/2
4.643
65
340.38
5531.175
95.56073858
2760.558619
419434.53
B/T4-50/3
3.064
65
254.8
4140.5
79.52161553
3618.932796
475783.63
Jenis
No
Spesimen
Komposit
Volume
20%
Volume
30%
Volume
40%
Volume
50%
Defleksi
Support
span
Beban
Momen
Bending
Teg Bending
Modulus
elastisitas
Kekakuan
(mm)
(mm)
(N)
(Nmm)
(MPa)
(MPa)
(Nmm2)
2538.4
37.3074662
1954.223293
359006.45
1680
26.10502871
1172.113121
205551.73
B/T5-20/1
3.771
80
126.92
B/T5-20/2
4.359
80
84
B/T5-20/3
5.271
80
119.54
2390.8
31.36043496
1143.470071
241907.29
B/T5-30/1
6.094
80
161.59
3231.8
54.53651848
1818.253282
282839.95
B/T5-30/2
8.7
80
202.57
4051.4
64.87326064
1472.927728
248361.69
B/T5-30/3
8.717
80
186.63
3732.6
65.00310204
1515.083109
228372.15
B/T5-40/1
5.937
80
345.83
6916.6
91.06758295
2704.394911
621332.88
B/T5-40/2
5.277
80
306.08
6121.6
85.17996289
3074.617176
618694.97
B/T5-40/3
3.928
80
186.16
3723.2
52.78638941
2492.937308
505526.14
B/T5-50/1
4.256
80
180.42
3608.4
33.50767838
1191.193529
452180.45
B/T5-50/2
5.522
80
226.56
4531.2
44.74522712
1234.755582
437638.54
B/T5-50/3
5.776
80
282.5
5650
55.75144395
1514.079733
521698.98
LAMPIRAN IV
Tabel 4.1. Sifat mekanik dari beberapa jenis serat.( Dieter H. Mueller )
Cotton
Flax
Jute
Kenaf
E-Glass
Ramie
Sisal
Diameter
m
-
11–33
200
200
5–25
40–80
50–
200
Length
mm
10–60
10–40
1–5
2–6
-
60–260
1–5
Tensile strength
MPa
930
1800
400–
1050
GPa
26.5
53.0
69.0–
73.0
61.5
Density
g/cm
345–
1035
27.6–
45.0
1.43–
1.52
393–
773
Young’s modulus
330–
585
4.5–
12.6
1.5–
1.54
1.5
2.5
1.5–1.6
Maximum strain
%
7.0–8.0
2.7–3.2
1.6
2.5–3.0
3.6–3.8
511–
635
9.4–
15.8
1.16–
1.5
2.0–
2.5
Specific tensile
strength
km
39.2
73.8
52.5
63.2
73.4
71.4
43.2
Specific stiffness
km
0.85
3.21
1.80
3.60
2.98
4.18
1.07
3
1.44–
1.50
1.5–
1.8
Tabel 4.2. Sifat mekanik dari beberapa jenis material polymers
(Smith, W.F., Hashemi, J., 2006).
Density
3
(gr/cm )
Ultimate
Tensile
Strength
(MPa)
Yield
Strength
(MPa)
Modulus
of
Elasticity
(GPa)
%
Elongation
at break
Izod
Impact
Strength
(J)
1.2
70
60
2.25
5
0.3
Phenolic
Polybutylene terepthalate
(PBT)
Nylon 66
1.705
56
52
7
1.3
0.18
1.355
55
67
12
148
0.27
1.095
62
63
2.1
152
7
Polyester
1.65
58
70
3.5
2.4
0.22
Polyethylene
0.925
16
16
0.25
350
1.068
Polypropylene (PP)
1.07
50
28
2.25
427
0.16
Polyvinyl Chloride (PVC)
Polymethyl Metharcrylate
(PMMA)
1.305
47
38
3.1
62
5.3
1.17
62
69
2.9
15
0.16
Type
Epoxy
LAMPIRAN V
UJI DENSITY SERAT
Tabel 6.1. ASTM D 3800-79.
ρs1
ASTM D 3800-79
= ( Mu x ρm ) / ( Mu – Mm ) …….....….[1]
ρs2 = (ρs1 – (ρa x wa)) / ws ………………… [2]
ws = (Mu – ρa) / Mu …………………….......[3]
ρs1
= massa jenis serat
ρs2
= massa jenis serat (kadar air : 0%)
ρa
= massa jenis udara = 0.08298 gr/cm3
m
= massa jenis air = 0.997
Mu
= massa serat di udara
Mm = massa serat dalam air
ws
= berat serat, gr
wa
= berat udara, gr
Tabel 6.2. Hasil Uji Density Serat Kenaf Dengan Kadar Air 10%
(ASTM D 3800 - 79).
Specimen
serat
Massa di
dalam air Ma
(gr)
30.616
30.599
30.529
30.536
1
2
3
4
Jumlah total
Massa jenis serat rata-rata
Massa di
udara Mu
(gr)
82.324
83.654
80.645
84.398
Massa jenis
air ρu (gr/cm3)
0.997
0.997
0.997
0.997
Massa jenis
serat ρs
(gr/cm3)
1.587
1.572
1.592
1.562
6.314
1.578
Density (gr/cm2)
Density Serat Ramie
1,592457645
1,595
1,59
1,585
1,58
1,575
1,57
1,565
1,56
1,555
1,55
1,545
1,587317784
1,578503959
1,572010894
1,562229512
1
2
3
4
Rata-rata
Spesimen serat
Grafik 6.1. Hasil Uji Density Serat Ramie.
Massa jenis
Massa jenis/densitas suatu material merupakan. perbandingan
antara berat dan volume dari material tersebut. Dalam menentukan massa
jenis suatu benda yang bentuknya beraturan dapat mudah kita lakukan
dengan menggunakan persamaan 2.1 ( Tipler, 1991).
ρ =
mu g
W
⇒ ρ = u …………………………………. (2.1)
V
V
ρ = massa jenis, gram/cm3
Wu = berat di udara, gram
mu = massa udara,gram
V = volume material, cm3
g = grafitasi,gram/second2 = 9,8 gr/sec2
Untuk benda dengan bentuk yang tidak beraturan, dimana kita
kesulitan untuk menentukan volumenya. Kita dapat menghitung massa
jenis dengan hukum Archimedes,bahwa berat benda di dalam air sama
dengan berat di udara dikurangi dengan gaya ke atas yang diberikan
oleh air. Gaya tekan ke atas merupakan volume dari benda tersebut.
Dengan massa jenis air murni ( ρ air) 0,997 gr/cm3 pada suhu 23ºC maka
volume benda dapat kita hitung dengan persamaan 2.2 dan 2.3 sebagai
berikut (Tipler,1991):
Cara I : V =
ρ=
(Wu - Wa )
.........................................(2.2)
 air
W   air
Wu
⇒= u
Wu - Wa
V
..................................(2.3)
Wa = berat di air, gram
Wu = berat di udara, gram
air = 0,997 gr/cm3
V = volume material, cm3
Cara II : Dengan Gelas Ukur  V = V1 – V2
V= volume benda, cm3
V1= volume benda + volume air
V2= volume air/water

LAMPIRAN VI
Analisa perhitungan fraksi volume serat ramie
Diketahui
:
Massa jenis serat (ρf)
= 1.578 gr/cm3
Massa jenis matrik Polyester (ρm)
= 1.65 gr/cm3
Specimen dengan Vf 20% tebal 1mm
Volume composit (Vc)
= 18.75 cm3
Volume serat (Vf)
= 20% x Vc
= 0.2 x 18.75 cm3
= 3.75 cm3
Berat serat (Wf)
= ρf x Vf
= 1.578 gr/cm3 x 3.75 cm3
= 5.92 gr
Volume matrik (Vm)
= 80% x Vc
= 0.8 x 18.75 cm3
= 15 cm3
Berat matrik (Wm)
= ρm x Vm
=1.65 gr/cm3 x 15 cm3
= 24.75 gr
Berat composit (Wc)
= Wf + Wm
= 5.92 gr + 24.75 gr
= 30.42 gr
Checking fraksi volume (Vf)
Vf 
Wf /  f
W f /  f  Wm /  m
x100%
𝑉𝑓 =
5.92 1.578
× 100%
(5.92 1.578) + (24,75 1.65)
𝑉𝑓 =
3.75158
× 100%
18.75158
𝑉𝑓 = 0.2 × 100%
𝑉𝑓 = 20%
Tabel perhitungan fraksi volume komposit serat ramie
Perhitungan
Fraksi Volume Serat Ramie
3
Volume composit Vc (cm )
Volume serat Vf (cm3)
Volume matrik Vm (cm3)
Berat serat Wf (gr)
Berat matrik Wm (gr)
Berat composit Wc (gr)
1mm
18.75
3.75
15
5.92
24,75
30,42
2mm
37.50
7.5
30
11.835
39
50,84
20%
3mm
56.25
11.25
45
17.7525
58.5
76,25
4mm
75
15
60
23.67
78
101,67
Perhitungan
5mm
93.75
18.75
75
29.5875
97.5
127,09
1mm
18.75
5.625
13.125
8.87625
17.0625
25,936
2mm
37.50
11.25
26.25
17.7525
34.125
51,878
4mm
75
22.5
52.5
35.505
68.25
103,755
5mm
93.75
28.125
65.625
44.38125
85.3125
129,69
Fraksi Volume Serat Ramie
40%
Volume composit Vc (cm3)
Volume serat Vf (cm3)
Volume matrik Vm (cm3)
Berat serat Wf (gr)
Berat matrik Wm (gr)
Berat composit Wc (gr)
30%
3mm
56.25
16.875
39.375
26.62875
51.1875
77,82
1mm
18.75
7.5
11.25
11.835
14.625
26,46
2mm
37.50
15
22.5
23.67
29.25
52,92
3mm
56.25
22.5
33.75
35.505
43.875
79,38
50%
4mm
75
30
45
47.34
58.5
105,84
5mm
93.75
37.5
56.25
59.175
73.125
132,3
1mm
18.75
9.375
9.375
14.7938
12.1875
26,98
2mm
37.50
18.75
18.75
29.588
24.375
53,963
3mm
56.25
28.125
28.125
44.3813
36.5625
80,94
4mm
75
37.5
37.5
59.175
48.75
107,93
5mm
93.75
46.875
46.875
73.9688
60.9375
134,91
LAMPIRAN VII
Konversi Satuan
LAMPIRAN VIII
Gambar Spesimen
Gambar hasil cetakan komposit serat Ramie dengan matrik polyester
untuk pengujian bending dan impact
Gambar specimen uji bending komposit serat ramie sebelum pengujian.
Gambar specimen uji impact komposit serat ramie sebelum pengujian.
Gambar specimen uji bending komposit serat ramie setelah pengujian.
Gambar specimen uji impact komposit serat ramie setelah pengujian.
Gambar specimen uji tarik komposit serat ramie sebelum pengujian.
Gambar ramie jenis pujon
Gambar mesin pengolahan ramie
Mesin pemisah serat ramie dengan batangnya
Proses Dekortikasi: Proses pemisahan serat dari batang tanaman,
hasilnya serat kasar disebut “China Grass “.
Mesin pemisah ramie
Mesin pembersih ramie
Proses Degumisasi: Proses pembersihan serat dari getah pectin, legnin
wales dan lain-lain, hasilnya serat degum disebut “ Degummed Fiber “.
Mesin pelembut serat ramie
Proses Softening: Proses pelepasan dan proses penghalusan baik
secara kimiawi maupun mekanis agar serat rami tersebut dapat diproses
untuk dijadikan seperti kapas.
Mesin pemotong serat ramie dan membukanya
Proses Cutting dan Opening: Proses mekanisisasi untuk memotong
serat dan membukanya agar serat tersebut menjadi serat individual untuk
serat panjang disebut “Top Rami” dan untuk serat pendek disebut “Staple
Fiber “.
Beberapa benang hasil pengolahan serat ramie
Serat ramie yang telah diproses sampai menyerupai serat kapas sudah
dapat dipintal menjadi benang untuk ditenun menjadi tekstil dari ramie
peringkat No.2 setelah sutera, (cotton nomor 7).

tugas akhir - UMS ETD-db Repository

Transcription

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