Developments in Radiation Curing for Inks

60 Pages·0.261 MB·English

by  Pira International Ltd

Developments in Radiation Curing
for Inks
Published by
Pira International Ltd
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UK
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ISBN 1 85802 570 2
© Copyright
Pira International Ltd 2006
Head of publications and events
Philip Swinden
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Publisher
Rav Lally
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Head of editorial
Adam Page
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Global editor
Nick Waite
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Head of US publishing
Charles E. Spear, Jr.
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Claire Jones
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Typeset in the UK by
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Contents
List of tables iv 4
List of figures v
Executive summary vii
1
New trends in UV/EB ink
technology 23
Introduction 23
Introduction and methodology 1 UV inks 23
Report scope 1 Flexo 23
Report objectives 3 Offset 26
Methodology 4 Inkjet 27
Definitions 4 EB inks 29
2
Economics of EB inks 30
Properties of EB-cured inks 30
Wet-trapping UV- and EB-curable flexo
inks for central impression presses 31
Radiation-curable inks overview 7 Hybrid ink technology 32
Raw materials 7 White UV ink for coding, marking and
Technology 9 packaging 35
Classification of UV inks 9 High-reflectance UV-curable silver and
Inks 10 gold inks 36
Printing methods 12 Summary 36
5
Applications 13
Flexographic printing 14
Digital printing 14
Printing technologies 14
Geographic markets 14 Key developments in applications of
Packaging applications 14 UV inks 37
3 Printing applications 38
Packaging applications 40
Flexible packaging 40
The state of UV/EB in graphic arts 41
Raw materials developments 17 Specialty UV ink applications 42
Introduction 17 Thermoforming UV ink applications 42
Raw materials developments 17 Specialty UV inks for selective doming
Monomers 17 applications 43
Oligomers 18 Special-effect graphics applications 43
Photoinitiators 20 UV glitter inks 43
Additives 20 UV photoluminescent inks 43
Raw materials for UV inkjet 20 Offset sheet-fed and web printing
New developments in equipment 21 applications 43
Summary 22 Food packaging applications 44
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Developments in Radiation Curing for Inks
Contents
Durable UV inks 45 EU regulations for food packaging 47
Cationic UV inks 45 UV/EB inks in Asian markets 47
Summary 45 Regulatory environment for printing /
6
packaging inks 47
Europe 47
US 48
Asia 48
Regulatory developments 47 New regulatory developments for printing/
Introduction 47 packaging ink 49
Key trends 47
Food packaging and ink regulations 47 Bibliography 51
Page iv © Copyright Pira International Ltd 2006
List of tables
2.1 Development in radiation curing in 5.1 Major application and market sectors
ink 14 for radiation curing processes for
2.2 Estimated sales of UV/EB inks and packaging 37
lacquers in packaging products in 5.2 Applications for UV inks in inkjet
Europe 15 printing 39
4.1 Typical working widths and printing 6.1 Regulatory developments for
speeds for flexo operations 24 radiation-curable inks 49
PPaaggee vv ©© CCooppyyrriigghhtt PPiirraa IInntteerrnnaattiioonnaall LLttdd 22000066
List of figures
4.1 Penetration of UV light in thick film
ink 33
PPaaggee vvii ©© CCooppyyrriigghhtt PPiirraa IInntteerrnnaattiioonnaall LLttdd 22000066
Executive summary
This report gives an overview of radiation-curable inks, focusing on recent trends in the
development of raw materials for radiation curing, technology processes and application
areas for energy-cured inks. Overall, this appears to be one of the most promising
technologies, likely to impact the packaging and printing industries.
Trends in raw With the current advances in raw materials for ink production, there seems to be no end
materials to where radiation-curable products may take us in the future. Raw materials suppliers
are expected to develop products based on the needs of ink formulators. Competition
among ink vendors is fierce, so they are looking for new and innovative ways to improve
ink performance at the same time as finding new applications that can benefit from
ultraviolet (UV) screen printing. The UV screen printing market has advanced in leaps
and bounds since the development of new UV inks; this trend will continue as raw
materials suppliers and ink manufacturers work to evolve their products and achieve new
performance standards.
Raw materials developments include:
 New multifunctional monomers to overcome difficulties in printing hydroscopic stocks;
 New oligomers with low viscosity and good formability for UV thermoformable
packaging;
 Oligomers with enhanced pigment wetting properties to prepare inks that require
greater latitude;
 Modified epoxy acrylate oligomers;
 New low-viscosity highly functional oligomers for UV inkjet inks;
 Grafting of photoinitiators for UV-curable food-contact inks.
Developments in Inventions and innovations in UV ink technology have opened up numerous market
technology processes segments for UV ink. The competition among UV ink manufacturers is leading to
better technology developments and more versatility in their application. The latest
developments have made printing of packaging faster and more economical, and the
print more attractive. UV ink technology can be applied in food packaging that has no
regulations governing volatile organic compounds (VOCs).
The most important technology developments covered in this report include:
 UV-cured flexographic inks
 UV-cured offset inks
 UV-cured inkjet inks
 Electron beam (EB)-cured flexographic inks
 Hybrid inks.
Page vii © Copyright Pira International Ltd 2006
Developments in Radiation Curing for Inks
Executive summary
Developments in The strongest segments of UV ink use are folding cartons and labels. While folding
applications for cartons are printed primarily using lithographic sheet-fed inks, labels typically are printed
radiation-curable flexo narrow web. In markets like narrow web labels, UV flexo has gained a strong position
inks and is considered a standard product. UV flexo is still emerging as a viable technology in
film printing. UV inkjet inks are one of the more exciting technologies being developed in
packaging applications. Inkjet printers are steadily capturing the digital printing market.
The major application areas for energy-cured inks include:
 UV-curable inkjet digital printing in packaging and label printing;
 UV-cured marking inks for coding and marking applications;
 Low odour UV flexo inks for narrow-web packaging applications;
 UV flexo inks catering to demands for improved graphics;
 UV-cured inks for digital printing used in corrugated packaging;
 New UV-curing inkjet inks widely used for plastics substrates;
 New UV inks offering metal solutions in rigid packaging solutions;
 New thermoforming UV ink formulations to improve finishing procedures on various
substrates;
 New specialty UV inks with high pigment loads for selective doming applications;
 New UV magnetic-receptive ink products ideal for point-of-purchase (POP) technology;
 New glitter UV inks to create shimmering effects in printed graphics;
 High-viscosity UV/EB paste inks widely used in offset sheet-fed and web printing;
 New UV/EB litho inks ideal for general purpose food packaging applications;
 Highly durable UV inks widely used to protect food and beverage brands;
 Cationic UV inks for food packaging.
This report also looks at various other specialty inks that are gaining prominence because
of their specific properties.
Radiation-curable inks have been in the limelight because of their environment-
friendly nature and the fact that they eliminate VOC emissions. This report concludes by
looking at specific issues and environmental regulations that govern the usage of this
technology.
Page viii © Copyright Pira International Ltd 2006
1
Introduction and methodology
New high-speed radiation-curable inks are being touted as one of the technologies that
will play a key role in the future printing and packaging industries. The environment-
friendly nature of the technology and the various developments that make it a
commercially attractive proposition are likely to be two of the major factors that will
strengthen the market share of this technology.
In the printing industry, there has been considerable effort from printing companies
to satisfy the growing need for stronger pigmentation and low-viscosity levels for each
and every colour. Radiation-curable technology can cater to these needs and more and
more companies are likely to embrace it in an effort to expand their market reach.
Radiation-curable technology is being used in screen printing, sheet-fed offset
printing and hybrid UV systems, and this has led to the opening up of new markets for
radiation-curable inks being used on conventional presses with UV lamps.
Sustained growth has been witnessed in the use of radiation-curable technology in
flexographic and digital printing, and narrow-web tag and label applications. Printers are
increasingly using UV digital technology for wide-format printing, such as billboards, to
enable faster speed to market for these advertisements. All of these markets understand
and appreciate the advantage of rapid curing speeds and embrace the low VOC emissions
associated with radiation-curable technology.
Recent innovations have allowed ink makers to create UV inks with advanced
adhesion, elongation, flexibility and water-resistance properties.
By taking advantage of recently developed backbones in the UV/EB industry vendors
are creating new raw materials with unique properties. There are a number of areas for
further growth for UV/EB inks, packaging applications being the main one.
Report scope Packaging has two basic types of production:
 Printing/coating
 Laminating.
Numerous different processes and materials can be used, such as:
 Offset
 Flexo
 Screen
 Rotogravure
 Hybrid
 Digital
 Lamination
 Coatings.
Material systems use solvents or water as a dissolving medium. There are also solvent-free
systems. Within the past two decades, the cross-linking of printing inks, varnishes and
adhesives has been undertaken using UV light or EB treatments in many packaging areas.
Page 1 © Copyright Pira International Ltd 2006
Developments in Radiation Curing for Inks
Introduction and methodology
In some sectors these treatments are applied only during certain parts of the production
process.
Examples of extensive applications in packaging markets include:
 Printing of labels
 Printing of cartons
 Printing on sausage packaging
 Printing on aluminium foils for lids
 Printing on tin-plated steel for cans and lids.
Applications of these technologies in packaging include:
 Stand-up pouches
 Liquid food packaging
 Labels
 Narrow-web/self-adhesives
 Shrink sleeves
 Stretch sleeves
 Folding cartons
 Metal packaging.
The areas of packaging materials and radiation-curing processes covered by our
research are:
 Flexible packaging
 Rigid packaging
 Cartonboard
 Metal.
Among the end-use sectors, the converter segments (printing and laminating) comprise:
 Fresh food
 Chilled food
 Frozen food
 Dried food
 Confectionery
 Baked goods
 Pet food
 Others, such as non-food and household.
In segments such as flexible packaging, medical packaging and paper there has been a
trend towards the application of only limited radiation curing of printing inks, adhesives
and varnishes. The technologies in radiation curing have also been influenced by broader
developments in the packaging industry. These depend on the reaction characteristics of
the materials used in curing processes:
 EB curing
 Free-radical curing with inert atmosphere (UV light)
 Free-radical curing (UV light)
Page 2 © Copyright Pira International Ltd 2006