High Light Fastness Printing of Polyester - esma
Transcription
High Light Fastness Printing of Polyester - esma
High Light Fastness Printing of Polyester Opening new digital print markets General Introduction • • • • Visible spectrum runs from Red to Violet Red light longest, violet light shortest Light shorter than 400 nm is called ultra violet (UV) Light longer than 700 nm is called infra red (IR) How does this impact color performance on polyester textiles? Inkjet Conference Page2 Corporate Light fastness on Polyester Textiles explained • • • • • Color fading and textile damage is caused by a small amount of the Suns energy called UV radiation UV accounts for only 2% of the Suns energy but accounts for 70% of the damage Printed polyester has grown significantly over past years e.g. Signage Polyester fibers are very resistant to abrasion, weathering and sunlight however current ink technologies used to digitally print it do not match fiber performance. Chemical structure of the disperse dyes used is critical to performance. Inkjet Conference Page3 Corporate End Use applications for Polyester Fibers Standard Textiles Established markets (dye sublimation inks) • Soft signage / Visual communication • Apparel / Fashion • Sportswear Technical Textiles Emerging markets (direct to fabric inks) • • • • • • Home Textiles (curtains, decorative) Automotive interiors Sun umbrellas Outdoor furnishings Outdoor awnings Outdoor flags and banners Color fastness to light & Heat key success factors for technical textiles Inkjet Conference Page4 Corporate Color Fading Scale 1- 5 according to end use 1 – Apparel/fashion fabrics 2 – Indoor signage/sportswear 3 – Indoor textiles (curtains)- protected by window glass (to some extent) and exposed to sunlight a few hours per day 4 – Automotive Textiles – exposed to longer times in sunlight and to temperature 5 – Outdoor textiles (awnings,sun umberellas) are exposed to direct sunlight worst condition for fading and fiber degradation Only 1 & 2 can be printed successfully with standard sublimation inks. Inkjet Conference Page5 Corporate Why not use pigments on PES? • Poor coloristic properties, no «pop» effect • Pigments are glued to fiber via binders causing harsh fabric handle / tackiness / stifness • Poor crocking / rub fastness • Poor fiber penetration • Poor abrasion resistance (automotive) • Binder containing inks tend to be more difficult to jet Applications limited more to non contact PES end uses Inkjet Conference Page6 Corporate Todays PES ink of choice Sublimation • • • • Most widely used textile ink today Low molecular weight Easy to apply via transfer paper Acceptable color fastness on − Indoor banners − Apparel and sportswear • Not suitable for more technical textile applications − − − − Poor light fastness properties Off tone color fading Low heat stability Poor weatherability fastness Inkjet Conference Page7 Corporate Direct to Fabric «Teratop» disperse inks • • • • Larger molecule / differentiated / patented chemistry Particles diffuse into PES fibers at high temp More difficult to process than sublimation inks Exhibit excellent color fastness properties − − − − − High Light fastness (UV) On tone fading High heat resistance – non migrating Excellent weatherability fastness Meets brands specifications The only solution to print technical textiles to tight color fastness specifications Inkjet Conference Page8 Corporate Fastness Tests Table of most common lightfastness test methods ISO 105 B02 Irradiance AATCC 16E 2) (Europe) ( USA) 1,0 W/m2 (420nm) 1,2 W/m2 (420nm) Toyota 3) TS L9900G met.1 Art. Weathering ISO 4892-2A 0,55 W/m2 (340nm) FAKRA 4) VDA 75202 1,2-1,3 (420nm) SAE J 1885 (USA) 0,55 W/m2 (340nm) Black standard temperature Black panel temperature Test chamber temperature Rel.Humidity Exposure conditions approx. UV limit (1% of irradiance at 420nm) Apparatus in Basel Inkjet Conference ~ 48 °C --- --- 65°C 100 °C ca. 95°C 45 °C 63 °C 89°C 45°C ca. 92-96°C 89°C 31-34°C 43 °C 62°C 35-38°C 65°C 62°C ~ 50 % 30 % ~ 50 % 65% ~ 20 % ~ 50% matches conditions behind glass more UV than matches behind glass, conditions less than outdoor behind glass matches to wet outdoor conditions more UV than behind glass, less than outdoor substantially more UV than outdoor 310-315 nm 300-305 nm 310-315 nm 290-295 nm 300-305 nm 6) 280-285 nm Atlas Ci35 IR/ Sodalime Atlas Ci35 Boro / Sodalime Atlas Ci35 5) Quartz/Boro/WG Atlas Ci35 cira/Sodalime/ WG Atlas Ci35 6) Boro / Sodalime Atlas Ci35 Quartz / Boro Page9 Corporate Fastness Test Xenonlight Articles that are exposured to light Test conditions : Temperature 35°C / Humidity 50% Sublimation ink Huntsman TERATOP Inks Pigment Inks Sublimation Inks Huntsman TERATOP Inks Blue Scale Target : 7 Exposure time 336 h Inkjet Conference Page10 Corporate Fastness Test Artificial Weathering Outdoor articles Test conditions : Temperature 35°C / Humidity 65% / Dry:Rain 18:102 min Sublimation ink Huntsman TERATOP Inks Grey Scale Target : 4 Exposure time 200 h Inkjet Conference Page11 Corporate Fastness Test FAKRA (Hot Light) Automotive interior Test conditions: Temperature 65°C / Humidity 20% / more UV light / one cycle 72 h Sublimation ink Huntsman TERATOP Inks Pigment Inks Sublimation Inks FAKRA 5x Inkjet Conference Page12 Huntsman TERATOP Inks Grey Scale Target : 4 Corporate Automotive interior applications case study • • • • • • 90 mio cars expected to be sold in 2015 Fabric interiors today are plain dyed or yarn dyed and woven, 10-15 m fabric / car Digital print ideal to personalise and simplify process Seats, belts, headliners, panels, sound absorption all PES End use ripe for conversion Only high tech dyes can meet the stringent specs demanded by the auto makers Inkjet Conference Page13 Corporate Summary • Technical textiles will be the next «big» inkjet revolution in − Automotive interiors − Outdoor Textiles • • • • Durability, color fastness, meeting brand specifications and application know how essential to drive market growth Machines already developed to print the end use applications, Pigments not the solution for PES technical textiles due to poor color durability, poor coloristic values, fabric handle Brand & retailers will play an important role in the market conversion. Inkjet Conference Page14 Corporate