pdf 2.5 MB Biaxially Oriented BOPP Barrier Films with thin EVOH

pdf 2.5 MB Biaxially Oriented BOPP Barrier Films with thin EVOH

Biaxially Oriented BOPP Barrier
Films with thin EVOH Layers
Brückner Maschinenbau GmbH, Siegsdorf, Germany
Dr. J. Breil, R. Lund, Dr. M. Wolf
European Metallizers Association, 9th+10th of March, 2006
Overview:
Introduction
Simultaneous biaxial orientation of different EVOH grades
LISIM Principle
LISIM Laboratory Line: High flexibility in choice of
base materials and machine settings
Results and Summary
Possible Applications: Research Project „Thin Films“, cost
comparisons
Path forward and Conclusion
© Brückner
Introduction:
High-Barrier-Materials Worldwide (in 1000 mt/ a)
Material
2000
2004
AGR
2008
AGR
PVDC Film
151
160
1,5%
164
0,6%
Metallized Film
115
152
7,2%
205
7,8%
EVOH Film
26
37
9,2%
55
10,4%
Glass coated film
10
16
12,5%
34
20,7%
PVOH
1
1
0,0%
2
10,7%
PAA coated Film
<1
1
Na
13
89,9%
60% of film consumption is transparent films, 40% is metallised
Only 5.3% of the total EVOH film consumption is oriented films
Source: Allied Development Corporation
© Brückner
Transparent bioriented OTR Barrier Films –Types and Advantages
Transparent biaxially oriented barrier films:
•Coated bioriented BOPP/ BOPET/ BOPA films:
SiOx, AlOx, PVDC, Acrylics, EVOH a.o.
•PVDC barrier films, mainly blown film
•EVOH barrier films, mainly blown film and double bubble films
(Exception e.g. Exxon Mobil Films), coated films
Advantages against e.g. metallized or non oriented films:
-
Microwaveability
Product visibility
Design potentials
Deep drawability
Improved mechanical and optical properties
Thinner EVOH-layers
© Brückner
B
O
B
PE
A
B
5
/7
/3
0
50
/5
0
12
/
12
12
PE
E
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/P
io
E
0
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0
/5
r2
12
ri e
E
ar
/P
12
0
/2
0
C
25
12
/5
20
0
26
/5
D
E
PV
PE
H
ox
/P
lu
-S
T/
PA
Si
S-
Tm
x/
VO
lo
M
PE
T-
O
PE
O
O
B
B
B
A
-E
p
T/
op
PE
B
O
x/
PE
io
B
/P
C
15
0
/5
0
20
/5
12
VD
E
C
/P
/P
VD
PP
PA
/P
O
T-
T/
-S
PE
PE
PP
O
O
O
B
B
B
B
O
E
PE
/P
T/
m
PE
PP
B
O
O
PE
B
B
WVTR [g/m²]
OTR [cm³/cm²xdxbar]
Comparison of different Barrier Films
100
OTR
WVTR
10
1
0,1
0,01
© Brückner
Packaging Requirements for Barrier Films
Packaging Good
OTR [cm3/ m2 d bar]
WVTR [g/ m2 d]
Peanuts, snacks
0,7-10
2-8
Baby food
0,1-0,8
0,7-3
Instant coffee
0,2-2
0,7-3
Vacuum coffee
0,2-3
0,8-5
Meat/ MAP
2-20
10-50
10.000-200.000
10-3.000
Fresh Meat b
20-40
2-4
Fresh Meat c
1-3
2-4
Fresh spec. cheese
7-11
300-700
30-4.000
600-3.000
Fruits, vegetables, salad
Fresh Bakery Products
© Brückner
Simultaneous biaxial orientation of different EVOH grades
Source:
© Brückner
Fundamental Issues:
Crystallisation behaviour of EVOH
Property overlap
●Crystallisation temperature overlaps the optimum orientation
temperature range of other polymers
Sequential orientation
●Sequentiell orientation of EVOH is difficult due to the orientation
crystallisation and formation of microfibril structure
Simultaneous orientation
●Simultaneous orientation at low stretching temperatures and/ or high
stretching speeds subdues crystallization
© Brückner
Processes for the production of biaxially oriented films
Sequential Stretching
MDO - TDO
Simultaneous Stretching
Pentagraph, Spindle, LISIM
Double-Bubble
© Brückner
LISIM® Principle
Linearmotor Simultaneous Stretching technology
Clips
Linear motors
Simultaneous stretched film
Cast-film
© Brückner
Comparison Sequential / Simultaneous
Simultaneous Stretching
Sequential Stretching
TD
10
9
8
7
6
5
4
3
2
1
MD
Useful area
MDO
TDO
10
9
8
7
6
5
4
3
2
1
MD
TD
Useful area
LISIM® Simultaneous stretch. technology
© Brückner
Comparison of mechanical film properties:
Sequential / Simultaneous
LISIM®
Sequential
Stretching ratio
(MD x TD)
Tensilestrength
[N/mm²]
Elongation at
break [%]
E-modulus
[N/mm²]
5x9
8x8
10 x 5
MD
140
258
310
TD
290
252
208
MD
200
78
52
TD
55
82
110
MD
2000
3060
4070
TD
3500
3130
2685
© Brückner
LISIM® Pilotline
© Brückner
LISIM® pilot line for simultaneous stretching
Film types
PET
PP
PA
1 –150
3 –60
5 –25
Stretching ratio MD
3 –6
6 –10
3 –5
Stretching ratio TD
3 –5
5 –10
3 –5
[m/min]
150
150
50
[kg/h]
250
200
70
Thickness range
Speed (max.)
Net output
Winder
(max.)
[ µm ]
LISIM®
stretching
oven
IRpreheating
Chill-roll
Extrusion
© Brückner
Laboratory Stretching Frame
 Low amounts of material needed
 Comparison of materials or mixtures
 Data for upscaling experiments
mode: simultan bei 155°C 7,5x7,5; 400%/s
35,00
E27_S
30,00
E32_S
Force [N]
25,00
E38_S
20,00
E44_S
15,00
E47_S
10,00
E44_N
5,00
E32_N
0,00
1
2
3
4
5
TD-Stretching Ratio [-]
6
7
8
© Brückner
Upscaling Process
Production-Line
Method




Evaluation of Process Window
Optimisation of Film Properties
Measurement of Stretching Forces
Simulation with
FEM-Method
Pilot-Line
 Upscaling to
production scale
Lab-Stretching Unit
Advantages





Demonstration of the LISIM® - Technology potential
Basic R & D for film stretching
Development of new film types
Development of new components
Production of Sample Rolls for Pre-Marketing
© Brückner
7-layer BOPP/ EVOH barrier film (Ethylene content 27%)
Cross section of the stretched film:
Total
© Brückner
7-Layer Film with EVOH ( Ethylen-Content 27% )
Comparison Simultaneous/Sequential
sequential 5x5
simultaneous 5x5
Improved orientation through suppression
of crystallisation behaviour
© Brückner
7-Layer Barrier Film
Influence of EVOH-ethylene-content on OTR-Values
4,5
OTR 23°C@75%RH
[cm³x20µm/m²xdxbar]
4
3,5
Stretching Ratio MDXTD=7x7
Stretching Temperature=160°C
Stretching Speed= 400%/s
3
2,5
2
1,5
1
0,5
0
25
30
35
40
45
50
Ethylene content [%]
© Brückner
Influence of OTR on relative humidity for BOPP based films
EVOH-thickness 1,5 µm
30
OTR [cm³/m²xdxbar]
27%
SiOx
25
PVDC
20
15
10
5
0
50
55
60
65
70
75
80
85
Relative Humidity [%]
90
95
100
© Brückner
Influence of the temperature on the OTR
OTR[cm³x25µm/m²xdxbar]
45
40
EVOH 30%
35
PVDC
30
25
20
15
10
5
0
0
20
40
60
Temperature [°C]
© Brückner
Comparision with Customary Barrier Films
Commercial 1
Commercial 2
7-Layer
PVDC coated
PVOH coated
(EVOH 27 % PE)
[µm]
26
25
29
[]
98
90
91
[%]
1,6
1,1
1,6
Shrink MD (120 °C, 5 min) [%]
3
3
4
Shrink TD (120 °C, 5 min) [%]
2,5
2,5
2
Young‘
s Modulus MD [N/mm²]
2200
2200
2526
Young‘
s Modulus TD [N/mm²]
3500
3500
1807
Tensile Strength MD
[N/mm²]
135
135
211
Tensile Strength TD
[N/mm²]
275
275
160
[µs]
0,25
0,25
0,15
20
3
1,4
4,2
5
4,5
Thickness
Gloss
Haze
Coefficient of Friction
OTR
[cm³/m²dbar]
(23°C / 75% RH)
WVTR
[g/m²d]
(38°C / 90% RH)
© Brückner
7-Layer High Barrier s-BOPP
Cost Calculation in €/kg
4
Production Costs
3,5
Material Costs
€/kg
3
2,5
2
1,5
1
0,5
Market Price
0,52
3,5
1,48
0
© Brückner
Barrier Shrinkfilm
Barrier properties: OTR: 3.5 cm³/m² d bar (23°C / 75% r.h.)
(before shrinkage)
WVTR: 11 g/m²d
(38°C / 90% r.h.)
60
BMS-Barriershrink MD
Shrink [%]
50
BMS-Barriershrink TD
40
30
20
10
0
80
90
100
110
120
Shrink temperature [°C]
130
140
© Brückner
Structure of a density reduced, opaque, barrier BOPP film
Simultaneous biaxial orientation
Terpolymer
Homopolymer, CaCo3
1,1 µm
12,7 µm
Adhesive Layer
0,5 µm
EVOH
1,4 µm
Adhesive Layer
0,5 µm
Homopolymer, CaCo3
12,7 µm
Terpolymer
1,1 µm
Gauge:
30 µm
Density: 0,78 g/ cm3
OTR:
1,2 cm3/ m2 d bar
23°C/50% r.h.
WVTR:
1,2 g/ m2 d
23°C/0 - 85% r.h.
© Brückner
Summary of the EVOH biaxial orienting tests:
Sequential stretching is possible at higher Ethylene content of 44%
Simultaneous stretching possible with all types, even with only 24%
ethylene content
High stretching speeds and/ or low stretching temperatures
suppress crystallization and thus „net structure“, good optics
Low OTR values
High flexibility due to choice of base material and machine
adjustments:
●Shrink barrier films
●Density reduced films
© Brückner
WVTR [g/ m2 d] (25°C/ 100% r.h.)
Barrier values for different film systems
BMS(1.5µm)
PET
metallized
PP-O
metallized
Steel
Aluminium
Glass
OTR [cm3/ m2 d bar] (25°C/ 50% r.h.)
Source: Alcan Packaging Homepage
© Brückner
Comparison of different BOPP barrier film systems
Metallized
AlOx
SiOx
EVOH
EVOH
transp.
opaque
PVDC
OTR
+
+
+
++
++
+
WVTR
++
+
++
o
o
o
Aroma
++
+
++
++
+
++
UV-
++
-
0
-
+
0
++
-
-
-
+
-
+
+
++
Protection
VIS Light
Protection
Colour Index
+
Flex-Crack
--
--
-
+
+
Retortability
--
++
++
-
-
++
+
o
-
--
+
© Brückner
Possible Applications: Research Project „
Thin Films“
Project coordination
Database
Simulation
End user
Filmproduction
simultaneous
sequential
Metallization
SiOx
Lamination
Print
Adhesive
Packaging
Packaging
properties
e.g. haptics
© Brückner
Definition of the targets
To demonstrate with selected
film systems
along the entire added value
chain
up to the final application,
that a 50% reduction in material
is possible without significant
limitations of the technical
functionality
© Brückner
Motivations for Material Reductions
Why should there be a further material reduction in film
packaging systems?
Cost savings and packaging law:
 Cost savings for a 50% reduction in thickness: Up to 17% (Calculation IVV).
 Climbing raw material costs increase the share of the raw material on total
production costs and therefore enforce higher yields
 The German Regulation of Packaging as well as the European packaging
directive 2004/12/EG make avoidance and material reduction a priority.
 Demonstration of conformity with the European packaging directive according
to DIN EN 13 427 ff.
 Reduction of material input at retained functionality is in this norm an explicitly
termed criteria.
Source:
© Brückner
Example for substituted film laminates, cost comparison:
Possible application: Peanuts
BOPET,12µm,
Reversed Print
Transparent
barrier, 27% E
Lamination
Lamination
BOPET, 12µm, metal.
Lamination
PE-LD, 50µm
Actual Standard
Thin sealing
film, 30 µm
Future Potentials
Material
PET 12µm //BOPETmet 12µm // 7-Layer EVOH 20µm // BOPP
PE-LD 50µm
17µm / PE-LLD 13µm
Process
Sequential
LISIM®
Gauge
76 µm
51 µm
Remark
Triplex Compound
2 Lamination steps
Duplex Compound
1 Lamination Steps
Packaging costs
212 €/ 1000 m2
147 €/ 1000 m2
Packaging cost reduction of ~ 28-32 % possible !
© Brückner
Additional cost reduction possibilities:
„Integrated production process“:
1-step simultaneous biaxial oriented PP/ EVOH/ PE
Terpolymer
Homopolymer
1 µm
10,5 µm
Adhesive Layer
0,5 µm
EVOH
1,5 µm
Adhesive Layer
0,5 µm
Homopolymer
10,5 µm
PE
30 µm
Gauge:
55 µm
© Brückner
Example for substituted film laminates:
Possible application: Peanuts
BOPET,12µm,
Reversed Print
Filmtyp
without
Lamination
Lamination
BOPET, 12µm, metal.
Lamination
PE-LD, 50µm
Actual Standard
Future Potentials
Material
BOPET 12µm //BOPETmet
12µm // PE-LD 50µm
7-Layer 20 µm / PE-LLD 30µm
Process
Sequential
LISIM®
Dicke
76 µm
55 µm
Remark
Triplex Compound
2 Laminating Steps
1 Step Process
Packaging
costs
212 €/ 1000 m2
118 €/ 1000 m2
Packaging cost reduction of ~ 40-45 % possible !
© Brückner
Path Forward and Conclusion
 Sample production for converting and packaging trials, discussions
with film converters and end users
 Optimization of properties, e.g. shrink, mechanical properties and tests
of further raw materials e. g. UV-Stabilizer or O2-scavengers
 Replacement of PVOH and/or PVDC coated films (cost 4 Euro kg)
 Possible application as shrink film (shrink 40% at 120°C@5 min)
 Replacement of film laminates (PA/ PE, PET/ PE)
 Penetration in the domain of metallized films (better flex crack
resistance, less leakage, opaque films)
© Brückner
Thank you very much for your attention!
© Brückner