Digital printing: Low Migration inkjet inks for indirect food packaging Roel De Mondt, Phd Agfa Gevaert N.V. Belgium ILSI Europe Packaging Symposium Berlin November 2012 Session II: Sustainable food contact materials
utline rganisation Sustainability in digital printing for food packaging Background on UV curable and Low Migration inkjet inks Innovations in Low Migration inks Summary and conclusions 2 R. De Mondt - ILSI Symposium on Food Packaging - November 2012
rganisation 53% 39% 8% 3 R. De Mondt - ILSI Symposium on Food Packaging - November 2012
Sustainability: what s your definition? 4 R. De Mondt - ILSI Symposium on Food Packaging - November 2012
Sustainable development Development that meets the needs of the present without compromising the ability of future generations to meet their own needs The process which fulfils social, economical and environmental needs successfully for the longer term and for future generations is called a sustainable process.! UNDERWRITERS LABRATRIES INC.: Standard for Sustainability for Printing Inks 5 R. De Mondt - ILSI Symposium on Food Packaging - November 2012
Drivers to go to Digital UV IJ printing for Packaging Cost and time savings Converters become print service providers Flexibility and speed: faster turnarounds: no more time-consuming and costly plate- or roll-making and processing. UV inks with long open time and fast curing The ability to print on a wide range of substrates gives digital presses important versatility over other printing methods, especially in UV. Digital printing s ability to do variable data printing (VDP), enabling the production of unique products Safety, track and trace, and brand protection. Reducing the environmental footprint by reducing substrate waste and working without VC and without pre-coats using UV inks. Regulation (EU) 1169/2011 provide info on the energy value and 6 nutrients in a nutrition table in a language easily understood by consumers easily visible, clearly legible and, where appropriate, indelible defined minimum font sizes drive to more variable printing and shorter runs digital printing 6 R. De Mondt - ILSI Symposium on Food Packaging - November 2012
Sustainable digital printing for food packaging? VC Substrate scrap Transportation Communication Accessible health information Warehousing QR Food safe print See Environment Short run Lead times Sustainable Digital printing 7 R. De Mondt - ILSI Symposium on Food Packaging - November 2012
What is a UV-curable (inkjet) ink made of and what should it (not) do? Colorant: pigment with dispersant Photoinitiator(s) and synergists UV curable monomer Surfactant Stabilizer/Inhibitor Any UV inkjet ink has to fulfill: Shelf life: at least 12 months, transporting all over the world, all climates and seasons Jetting performance and reliability: ink behaviour inside the printhead and during printing process Image quality and ink spreading Curing: solidification of the ink at the right speed ptical properties: gloss, colour, sharpness, Physical properties: adhesion, flexibility, scratch resistance, 8 R. De Mondt - ILSI Symposium on Food Packaging - November 2012
Low Migration digital printing inks Myth : Low Migration inks don t exist, especially not for UV Inkjet LM inks can fulfill the requirements set out in legislations and requirements, if proper care is taken in designing and maintaining the whole print system (substrate-ink-printhead-curing) What can go wrong? 9 R. De Mondt - ILSI Symposium on Food Packaging - November 2012
How to create LM inks? The ink carrier in UV inkjet Preferred for LM: Highly reactive, bulky, multifunctional monomers The photoinitiators Norrish Type I Norrish Type II In contrast with viscosity and high cure speed Tackled by our team by using: low viscous, highly reactive monomers, in-house invented, produced under license externally. specific combinations of polymeric, reactive (acrylate functionalised: focus on Norrish Type II and amine synergists), multifunctional and proven low toxicity photoinitiators. 10 R. De Mondt - ILSI Symposium on Food Packaging - November 2012
Dendritic PI s Polymeric initiators have been known for some time and are commercially available, but polymers are typically not at inkjet viscosity Solution A special design of the polymer architecture Dendritic structures have high molecular weight but a compact size low viscosity BUT: they are obtained in multistep synthesis: so Even better solution Specifically designed technology (e.g. EP 1616920 B, EP 1674499 B) Hyperbranched polymeric initiators = imperfect dendritic structures They are obtained in a two step synthesis: so Value of this technology acknowledged by third parties PI manufacturers interested in this technology: EP opposition 11 R. De Mondt - ILSI Symposium on Food Packaging - November 2012
Dendritic PI Amount of extracted PI 100 % 36 % 28 % 12 R. De Mondt - ILSI Symposium on Food Packaging - November 2012
Polymerisable PI s N S Cpd II N S Ref 1 Cpd I w/w/% Ink 1 Ink 2 Ink 3 Ink 4 DPGDA 42.5 41.5 45 43.5 TMPTA 40 40 40 40 Cpd I 10 Ref 2 Cpd II 10 Ref PI 1 7 Ref PI 2 7.5 N Cpd III Cpd III 5.5 6.5 EHA 6 7 DBP 2 2 2 2 N EHA 13 R. De Mondt - ILSI Symposium on Food Packaging - November 2012
Polymerisable PI s EP2189477 The polymerisable compounds create an ink formulation that: yields lower amounts of extractables than their regular counterparts maintains comparable cure speeds with an ink viscosity in the range of inkjet applications. Viscosity 25 ºC (mpa.s) Curing speed (rating: 0-5) Extractable initiator (mg/m²) Extractable co-initiator (mg/m²) Ink 1 37 2 0 0 Ink 2 35 2 0 0 Ink 3 31 1 19 2 Ink 4 30 1 39 13 14 R. De Mondt - ILSI Symposium on Food Packaging - November 2012
Combined technologies Dendritic meets reactive PI (EP2033949) 15 R. De Mondt - ILSI Symposium on Food Packaging - November 2012
Setup Results Sample Viscosity @ 25 ºC (mpa.s) Curing speed (rating 0-5) Extractable initiator (mg/m 2 ) Extractable co-initiator (mg/m 2 ) INV-1 85 0 0 0 INV-2 92 0 0 0 INV-3 68 0 0 0 INV-4 37 2 0 0 INV-5 35 2 0 0 C-1 31 1 19 2 C-2 30 1 39 13 16 R. De Mondt - ILSI Symposium on Food Packaging - November 2012
Summary and conclusions Sustainable packaging and digital printing Digital printing can be an answer to the need for sustainable packaging e.g., digital printing lowers waste (substrates and inks, printing too much of the same), renders lower cost, brings quality information to the public in a safe way Printing inks and food packaging Food packaging (primary) needs the use of Low Migration inks UV inkjet allows to print on many different types of packaging at high printing speed LM UV inks need careful design, especially in the case of IJ inks, because of the low viscosity Printing process and food packaging UV-curable printing process requires control of all parameters (e.g. curing, ink load, ) The legal boundaries can be used as a source of information: e.g. the Swiss rdinance UV-curable inkjet inks It is possible to formulate LM inks based on commercial compounds, but standard LM ink compounds (high MW, multifunctional) easily result in a viscosity too high for inkjet printing Proprietary UV-curable Low Migration inkjet ink technology the right choice of monomers: low viscous and highly reactive innovations on the photoinitiator and co-initiator side: dendritic or polymerisable photoinitiators yield highly reactive low viscosity ink formulations with low extractables this also results into formulation flexibility for adding compounds to tune the ink s functionality: adhesion, flexibility, withstand post-treatments such as sterilisation 17 R. De Mondt - ILSI Symposium on Food Packaging - November 2012
For your kind attention Dr. Roel De Mondt Project Manager Inkjet Inks Email: roel.demondt@agfa.com 18 R. De Mondt - ILSI Symposium on Food Packaging - November 2012
For your kind attention Dr. Roel De Mondt Project Manager Inkjet Inks Email: roel.demondt@agfa.com 19 R. De Mondt - ILSI Symposium on Food Packaging - November 2012
For your kind attention Dr. Roel De Mondt Project Manager Inkjet Inks Email: roel.demondt@agfa.com 20 R. De Mondt - ILSI Symposium on Food Packaging - November 2012
For your kind attention Dr. Roel De Mondt Project Manager Inkjet Inks Email: roel.demondt@agfa.com 21 R. De Mondt - ILSI Symposium on Food Packaging - November 2012