Digital low migration printing

Technology status and benefits Roel De Mondt, PhD – Agfa Gevaert N.V. – Belgium

Packaging and Can Coatings - June 2013 - Dusseldorf

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Outline

• Organisation

• Short background on inkjet printing

• Benefits in digital printing for food packaging

• Background on UV curable and Low Migration inkjet inks

• Innovations in Low Migration inks

• Summary and conclusions

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Organisation

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AGFA-GEVAERT OVERVIEW 2012

Sales by Division

Graphics 53%

Healthcare 39%

Specialty Products 8%

FY 2012

EUR 3

billion

Headquartered in Antwerp, Belgium

Founded in 1867, IPO in 1999 (Brussels)

Sales of EUR 3 billion in 2012

11,512 employees (FTE) worldwide

Wholly owned sales organizations in more than

40 countries

21 R&D and production sites around the globe

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Short background on inkjet printing

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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 VOC and without pre-coats using UV inks. • Regulation (EU) 1169/2011

• provide info: energy and nutrients • language easily understood by consumers • easily visible, clearly legible and indelible • defined minimum font sizes drive to more variable printing shorter runs digital printing

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Sustainable digital printing for food packaging?

Communication

Accessible health

information

QR

Food safe print

VOC

Substrate scrap

Transportation

Warehousing

See Environment

Short run

Lead times

Sustainable

Digital printing

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What is a UV-curable (inkjet) ink made of

and what should it (not) do?

UV curable

monomer

Photoinitiator(s) and synergists

Colorant: pigment with

dispersant Surfacta

nt 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

• Optical properties: gloss, colour, sharpness, …

• Physical properties: adhesion, flexibility, scratch

resistance, …

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Low Migration digital printing inks

• Myth : You can buy Low Migration inks 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?

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How to create LM inks ?

•The ink carrier in UV inkjet

•Preferred for LM: Highly reactive, bulky, multifunctional monomers

•In contrast with viscosity and high cure speed…

•The photoinitiators

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.

Norrish Type

I

Norrish Type II

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What to look out for?

• Purity

• Analytical efforts (supplier or ink producer)

• Specific note on pigments

manageable

• Nature of compounds: e.g. photoinitiators

• Assessed and found of low toxicity

• Polymeric

• Polymerisable

• Reaction products

• Non intentionally added compounds of another level than impurities

• Tricky compounds because unknown when formulating

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What have we been doing?

• Complete crosslinking technology:

Focus on monomers and photoinitiators

• Monomer:

• Photoinitiators

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Reaction product pitfall

wt% Ink 1 Ink 2 Ink 3 Ink 4

VEEA 45 45 32 45

DPHA 20 20 20 20

Type I PI-1 9 9 9 9

POLYMABL AMINE SYN 1 5 5 5 5

Cl-TX 1 20

Cl-TX 2 20

F-TX 1 33

F-TX 2 20

DBP 1 1 1 1

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DPHA is dipentaerythritol hexaacrylate:

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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 Ordinance

• 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

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For your kind attention

• Roel De Mondt

• Project Manager Inkjet Inks

• Email: roel.demondt@agfa.com