Greg Hrinya, Editor11.11.21
The proliferation of digital printing equipment has necessitated state-of-the-art supplies to ensure top quality print. Not only are label converters investing in digital printing at a strong rate, they are identifying inkjet printing as the means to meet brand requirements.
Inkjet is a non-contact print technology, which opens up multiple substrate and application possibilities that are closed off or more difficult to achieve with other technologies. Inkjet ink, by definition, is a low viscosity fluid and a stable dispersion of pigment particles ground just right to jet predictably through printhead nozzles, regardless of drop size. These inks require more processing than other inks, such as flexo inks, and are manufactured to tighter tolerances to ensure their reliability.
“Pigment particles for conventional inks are too big to work in top-of-the-line inkjet nozzles of the kind used in production inkjet label presses,” explains Victor Gomez, director of Industrial Labels, Epson America. “The pigment for digital printing needs to be micro-milled and treated chemically to disperse properly and stably. The right amount of pigment load is also important to maintain the low viscosity needed to perform consistently through the ink circulation and delivery systems, through the printheads and on the substrate.”
According to Andrew Berritt, marketing manager, Fujifilm Corporation, WFIJ System Business Headquarters, inkjet inks are fired through a nozzle with an aperture thinner than a human hair. “When you compare this to all other ink technologies, there are no similar limitations,” he says. “So, all the attributes required in an ink system become even more challenging. These include color vibrancy, color opacity, adhesion and flexibility properties.”
Viscosity is a fundamental element for success in inkjet printing. “Keeping the ink system consistent and stable for the shelf life of the product is key,” adds Berritt. “The reason this is so important and such a challenge is because we need to produce a highly reactive system that will cure under the right conditions almost instantaneously. But, at the same time, we need the viscosity to remain completely consistent. We need the viscosity and structure of the ink to remain completely stable so that jetting properties will be consistent, whether the ink is one month or 11 months old. Consistent, repeatable jetting is critical to drop placement and therefore image quality.”
Converters must consider their end-use markets when selecting inkjet inks. The speed, image quality and productivity of the printing machine become important aspects of the investment strategy, and the cost and reliability of the ink play an important role in the total cost of ownership.
“The most important aspect for customers to consider is the required durability of the prints and their suitability for the end application, which means that the appropriate selection of inkjet ink type is important in the first instance,” comments Phil Jackman, global product manager, digital, Sun Chemical. “Most industrial inkjet label printers on the market today utilize energy curable UV technology in some form, but there is an emerging desire for aqueous inkjet technology for many applications.”
“Ideally, the ink should be Newtonian fluid or just slight thixotropic to allow for good flow into the chamber of the printhead and jetting performance,” states Kenzi Suzuki, director of R&D Inkjet Technology for INX International Ink Co. “Inkjet printers are also very delicate and sensitive to the change of atmosphere. It’s recommended to use the printer in a temperature and humidity-controlled environment for the best printing performance results.”
UV inkjet inks are very durable when it comes to resistance to scuffing and scratching, soap, chemicals, and heat, notes Lode Deprez, VP of technology at Xeikon.
“The ink does not require contact between the printing head and the substrate,” says Deprez. “These properties explain why UV inkjet has gained a firm foothold in the health and beauty market and why it is the technology of choice for durable labels on household and industrial chemicals or for industrial labels on all sorts of tools and equipment.”
Xeikon’s PantherCure inks have been developed with the goal of performing optimally in terms of safety, performance and adhesion without the need for pinning, which gives a better overall gloss effect. Deprez adds that UV-curable inkjet ink can be dye-based or pigment-based. Most UV-curable inks, however, are pigment based because they are used in applications that require a high degree of lightfastness.
There is also a key relationship between the inks and the printheads. “The printing hardware, particularly the printheads, is still evolving with higher print speeds, smaller drop sizes and higher resolutions available now,” says Jackman. “So, formulating inkjet inks is a continuous process in the very dynamic world of print.”
According to Gomez, inkjet press manufacturers build in automated maintenance routines that keep printhead nozzles clear and ready to jet in order to keep the system functioning reliably. Ink is kept in circulation at a stable temperature, which optimizes the viscosity, and there is no settling of the pigments. This is especially important with white ink. There are a host of other factors to keep in mind, as well.
“As automated as these systems may be, converters need to be aware of the part they play in the proper functioning of their inkjet press,” adds Gomez. “Discipline in maintenance is critical – not just cleaning the head but also the rollers and other areas suggested by the manufacturer. Any artifact, such as paper dust from poorly slit rolls, for example, can potentially block a nozzle.”
Selecting the right ink
There are many factors that will impact the right ink for a given press. When dealing with inkjet inks, there are many advantages compared to analog inks. These include short-run capabilities, short response times, variability, stock reduction, local production and more.
Which ink is right for your press? Kao Collins has worked diligently to answer that question. Kao Collins has launched “InkAnswers,” a comprehensive digital search tool that matches inks with substrates used in label and narrow web production.
InkAnswers simplifies the process of identifying which inks are compatible with printhead technologies and materials, including flexible packaging, foil, shrink sleeve film, and variable facestock.
Stephen Buchanan, Kao Collins inkjet business manager, says, “It’s the right time for InkAnswers because the number one question we hear converters asking is ‘What inkjet ink should we use for this substrate?’ There are many variables when choosing inks. It gets complicated quickly.”
InkAnswers offers quick results for some of the most common printing needs such as sustainability, reducing ink migration, reducing downtime and more. “We are confident InkAnswers will build more awareness of industrial inkjet printing capabilities and the versatility provided by inkjet inks and technology,” Buchanan adds.
Fujifilm’s Berritt states that picking the right inkjet partner is crucial. “The cost of failure is much higher with inkjet inks and overall quality and consistency of the product, therefore even more important,” he comments. “Printheads are very expensive and often the first to suffer with poor ink systems.”
As Xeikon’s Deprez notes, there are many factors to take into consideration. “You need, in general, three times more ink to print the same design, basically because of the jetting and the need for low viscosity, and due to the technology,” explains Deprez. “The inks are also much more expensive to make, as all the components and particles have to be smaller than 150 nm, which creates a lot of challenges in the reproducible making of stable inks.”
Due to these factors, designs with UV inkjet will always have much thicker ink layers, which can be problematic when using this technology in thin flexible packaging applications, for example. Water-based, either pure or hybrid, is generally better suited for this segment.
In addition, more is required from a single inkjet ink. “In general, one ink has to do it all. This is very different from flexo printing, where the ink is adapted to the design, the need, the substrate, the post-printing process and so on,” comments Deprez. “This is not possible in inkjet printing, where you can’t switch the ink easily. Plus, UV ink stability features very high reactive mixtures, and due to low viscosity – linked to small molecules – there is a high degree of difficulty to make these inks food packaging compliant or even low migration optimized. This is challenging when combined with the ever-changing regulatory landscape that continually limits the use of the amount of products allowed to be used for UV ink making.”
Water-based inks have the balance between no evaporation at the nozzle plate in the head (also when not printing for a long time) and the extreme drying and image quality challenges when printing on non-absorbing substrates like polymer films.
Epson’s Gomez states that the current supply chain challenges further reinforce the importance of selecting a trustworthy partner. “As the current stresses on the worldwide supply chain show, the strength of the ink supplier needs to be carefully considered,” he remarks. “Epson hasn’t had the same delivery issues as other suppliers because of the redundancy in our supply chain. Ink for our color label presses is manufactured in any of half a dozen factories in different countries. The international nature of Epson’s business also means we saw the crisis build from its early stages last year, so we were prepared when it reached North America. Other press manufacturers buy their printheads and inks from third parties – a step removed that could entail supply risk.”
Inkjet ink development is not a rote process in which anyone can partake. There is incredible science and nuance that is required.
“Ink design is not for the meek,” says Gomez. “It entails creating a formulation that performs reliably for a variety of applications and substrates. It must be stable under most storage conditions, with high-grade ingredients treated and mixed in a sophisticated manufacturing process with specialized equipment and a highly skilled workforce. The formulation must be matched with the printhead and the ink storage, circulation and delivery systems, including the printhead.
It must have a reasonable expiration horizon to withstand transport and storage, too.”
Ink improvements
As more and more converters opt for digital inkjet printing technologies, the inks have had to evolve, as well. Many of these inks must satisfy a printer’s need for more diverse applications, including flexible packaging, shrink sleeves, in-mold and so on. Traditionally, flexo inks have been the remedy in this arena.
The improvements regarding inkjet inks have been twofold: the inks and the printheads. “Both inkjet inks and printing heads have seen significant improvements,” states Xeikon’s Deprez. “The performance and life of some of the piezo printheads have improved. Print resolution is gradually moving up, and architectures are going toward ink circulation in the heads. There is also a lot of intelligence being developed to compensate for failing nozzles. These improvements will find their way toward the industrial application field in the next coming years.”
Modern printers are becoming more intricate with a vast number of printheads and nozzles that need to stay in good working order if customers are to receive a good return on their high productivity capital investment.
“Inkjet is an evolving and scalable technology but has reached the point whereby most applications can be served by the speeds, widths and image quality that can now be achieved,” says Sun Chemical’s Jackman. “Thus, the onus is on the inkjet chemistry to satisfy the end-use requirements and perform reliably in the printing phase. If these technical requirements can be achieved, and the economics fit the business model, then significant adoption is seen.”
According to Jackman, inkjet ink formulations are moving more toward water-based technology where possible, whether that is new market developments or existing UV ink applications that can now be served with the latest development in aqueous inkjet technology. “This is due, in part, to regulatory compliance for food packaging, but increased sustainability demands are also driving this trend,” he notes.
Another key trend involves the advancement and availability of LED curable inks, as opposed to mercury lamp curing. “LED has been used for pinning for some time now, but its use has expanded to the full cure in presses like the Epson SurePress L-6534VW,” comments Epson’s Gomez. “LED avoids the high temperatures that mercury lamps give off, so curing with LED obviates the need for expensive chill rollers when printing on thin (e.g., unsupported film) or heat sensitive (e.g., heat shrink) substrates. LED curing takes less energy overall. LEDs also power on and off instantly, which means there is not time wasted waiting for the traditional lamp to power up.”
For Fujifilm, inkjet inks must keep up with the surrounding technology. “Adhesion to new, challenging media is becoming an increasing issue,” states Berritt. “This is true particularly when looking at non-PVC print media such as polystyrene and polypropylene.”
New products
As Epson’s Gomez notes, “Ink design is not for the meek.” Suppliers have worked tirelessly to optimize ink sets to thrive with many of the latest digital printing presses and printers. When selecting Epson, converters have the advantage of working with a manufacturer that develops its own inks, which provides company expertise, economies of scale, and technology to keep expanding its offerings.
“The SurePress L-4533AW uses Epson’s water-based, resin-coated pigment inks,” says Gomez. “The SurePress L-6543VW uses Epson LED curing inks. Epson invests directly in hygienic systems and processes to produce ink for its SurePress digital inkjet presses that is suitable for food applications and conforms to US FDA current Good Manufacturing Process (cGMP) guidelines and European Food Contact Materials regulations.”
Fujifilm offers a wide range of inkjet products for this market. These Fujifilm inks have been branded as Uvijet, and these inks have been formulated for a variety of systems consisting of varying printheads and curing systems, Fujifilm’s Berritt notes.
INX International Ink Co. provides a wide variety of solvent and UV inks for this market. “We carry many products for aftermarket use and others that have been designed with a customer’s specific needs or application in mind,” explains Sofia Machain, product manager-digital for INX International Ink Co. “That is the true benefit of working with us. If we don’t already have a product available, we will develop one for you that meets all regulatory needs.”
Sun Chemical remains committed to UV technology despite the tightening of the regulatory landscape, especially as UV will remain the dominant technology in labeling for years to come, says Jackman. Sun Chemical has a range of inkjet inks on offer under its SunJet brand. These include its SunJet Etijet inks for narrow web and labels, as well as its Amphora range for packaging. Where applicable to food packaging, both ink ranges are manufactured in accordance with good manufacturing practices and formulated in line with guidelines for food packaging applications.
Amplio falls under Sun Chemical’s SunJet brand and is a full range of digital effect solutions. The range comprises gloss varnishes, cold foil adhesives, lamination adhesives and varnishes for digital effects. These are primarily used for folding cartons for luxury goods such as perfumes and cosmetics and high-end labels requiring embellishment with tactile effects and metallic foils.
“Sun Chemical’s UV inkjet solutions are continually being reviewed to ensure compliance with regulatory updates that encourage cleaner labeling of UV ink for labels and improved product performance,” says Jackman. “Sun Chemical recognizes the importance of the total process in packaging. The application of inkjet inks, in conjunction with primers, adhesives and varnishes, is essential to meet some packaging requirements. Sun Chemical’s SunEvo range of coatings can help printers and converters of flexible packaging, paper-based packaging, narrow web and labels, folding carton and corrugated unleash the full power of digital printing.”
Xeikon, in partnership with parent company Flint Group, has developed UV inkjet products for its Panther Series presses. The inks feature durable performance, stability and compatibility with most label substrates. “These inks meet the demands of brand owners for high gloss and durable labels with high scuff resistance,” notes Xeikon’s Deprez. “The Panther DuraCure UV technology produces high gloss effects that stand out across the widest color gamut while delivering outstanding long-term durability for multiple applications.”
The inks have been optimized for multiple end uses, including industrial, chemical and household labels, as well as high-end labels for the premium beer, beverage, food, and health and beauty market sectors. For a water-based option, Xeikon offers Idera, which adheres to food/migration compliancy and is also Swiss and Nestlé list compliant. This ink displays a good balance between open time and drying, and compatibility with many corrugated substrates. It has been engineered for coated and uncoated materials, in general with the aid of a primer.
The advanced capabilities of Xaar’s Ultra High Viscosity technology demonstrate the difference that inkjet printing can make to labels and packaging, the company says. Part of Xaar’s ImagineX platform, Ultra High Viscosity technology ensures Xaar’s printheads deliver high impact, and productive and efficient results for volume digital label and packaging printing applications.
By enabling an extended high color gamut and fluids with larger particles and more pigment, colors are more vibrant, and whites and blacks are stronger. The ability to print high opacity, especially whites, in a single pass is useful for delivering impact on many labels and direct-to-shape package printing applications, as well.
In addition, fluids and inks with viscosities of up to 100 centipoises (cP) can be jetted in a single pass, further opening up opportunities for label and packaging printers to deliver new and exciting finishes for clients across a wider variety of packaging materials, with a high degree of efficiency and productivity.
Energy is also saved because UV fluids, which previously required heating to 45 degrees Celsius before jetting, can now be laid down at room temperature. Overall, less fluid is required, making the process even more sustainable.
Further, high-build varnish embellishments can be achieved more easily to add texture, visual impact, and functionality (such as ink that resists cracking on flexible surfaces) to labels and packaging. From Braille and tactile warning triangles on labels, to the latest haptic effects for a high-end look and real shelf presence for rigid and flexible packaging, with Xaar’s Ultra High Viscosity technology, results can be achieved that have traditionally only been possible by using screen printing.
Graham Tweedale, general manager of Xaar’s printhead business unit, says, “We are already seeing how Ultra High Viscosity technology is opening up new possibilities for Xaar in a number of applications, particularly labels and packaging. Whereas previously inkjet printheads have typically been only able to jet fluids of around 8 to 12 cP, our technologies enable printers to jet much higher viscosities, achieving a wider color gamut and unparalleled opacity, and can be used to print an extensive range of special effects.
“In addition, after many years of requests from clients to be able to print higher molecular weight photopolymers to increase resistance and flexibility for printed materials, our Ultra High Viscosity technology has realized this capability, truly unleashing the power of inkjet,” he adds.
Ultra High Viscosity technology is available across many of Xaar’s printheads, including the Xaar Nitrox, the 50x series, and Xaar 2002.
Inkjet is a non-contact print technology, which opens up multiple substrate and application possibilities that are closed off or more difficult to achieve with other technologies. Inkjet ink, by definition, is a low viscosity fluid and a stable dispersion of pigment particles ground just right to jet predictably through printhead nozzles, regardless of drop size. These inks require more processing than other inks, such as flexo inks, and are manufactured to tighter tolerances to ensure their reliability.
“Pigment particles for conventional inks are too big to work in top-of-the-line inkjet nozzles of the kind used in production inkjet label presses,” explains Victor Gomez, director of Industrial Labels, Epson America. “The pigment for digital printing needs to be micro-milled and treated chemically to disperse properly and stably. The right amount of pigment load is also important to maintain the low viscosity needed to perform consistently through the ink circulation and delivery systems, through the printheads and on the substrate.”
According to Andrew Berritt, marketing manager, Fujifilm Corporation, WFIJ System Business Headquarters, inkjet inks are fired through a nozzle with an aperture thinner than a human hair. “When you compare this to all other ink technologies, there are no similar limitations,” he says. “So, all the attributes required in an ink system become even more challenging. These include color vibrancy, color opacity, adhesion and flexibility properties.”
Viscosity is a fundamental element for success in inkjet printing. “Keeping the ink system consistent and stable for the shelf life of the product is key,” adds Berritt. “The reason this is so important and such a challenge is because we need to produce a highly reactive system that will cure under the right conditions almost instantaneously. But, at the same time, we need the viscosity to remain completely consistent. We need the viscosity and structure of the ink to remain completely stable so that jetting properties will be consistent, whether the ink is one month or 11 months old. Consistent, repeatable jetting is critical to drop placement and therefore image quality.”
Converters must consider their end-use markets when selecting inkjet inks. The speed, image quality and productivity of the printing machine become important aspects of the investment strategy, and the cost and reliability of the ink play an important role in the total cost of ownership.
“The most important aspect for customers to consider is the required durability of the prints and their suitability for the end application, which means that the appropriate selection of inkjet ink type is important in the first instance,” comments Phil Jackman, global product manager, digital, Sun Chemical. “Most industrial inkjet label printers on the market today utilize energy curable UV technology in some form, but there is an emerging desire for aqueous inkjet technology for many applications.”
“Ideally, the ink should be Newtonian fluid or just slight thixotropic to allow for good flow into the chamber of the printhead and jetting performance,” states Kenzi Suzuki, director of R&D Inkjet Technology for INX International Ink Co. “Inkjet printers are also very delicate and sensitive to the change of atmosphere. It’s recommended to use the printer in a temperature and humidity-controlled environment for the best printing performance results.”
UV inkjet inks are very durable when it comes to resistance to scuffing and scratching, soap, chemicals, and heat, notes Lode Deprez, VP of technology at Xeikon.
“The ink does not require contact between the printing head and the substrate,” says Deprez. “These properties explain why UV inkjet has gained a firm foothold in the health and beauty market and why it is the technology of choice for durable labels on household and industrial chemicals or for industrial labels on all sorts of tools and equipment.”
Xeikon’s PantherCure inks have been developed with the goal of performing optimally in terms of safety, performance and adhesion without the need for pinning, which gives a better overall gloss effect. Deprez adds that UV-curable inkjet ink can be dye-based or pigment-based. Most UV-curable inks, however, are pigment based because they are used in applications that require a high degree of lightfastness.
There is also a key relationship between the inks and the printheads. “The printing hardware, particularly the printheads, is still evolving with higher print speeds, smaller drop sizes and higher resolutions available now,” says Jackman. “So, formulating inkjet inks is a continuous process in the very dynamic world of print.”
According to Gomez, inkjet press manufacturers build in automated maintenance routines that keep printhead nozzles clear and ready to jet in order to keep the system functioning reliably. Ink is kept in circulation at a stable temperature, which optimizes the viscosity, and there is no settling of the pigments. This is especially important with white ink. There are a host of other factors to keep in mind, as well.
“As automated as these systems may be, converters need to be aware of the part they play in the proper functioning of their inkjet press,” adds Gomez. “Discipline in maintenance is critical – not just cleaning the head but also the rollers and other areas suggested by the manufacturer. Any artifact, such as paper dust from poorly slit rolls, for example, can potentially block a nozzle.”
Selecting the right ink
There are many factors that will impact the right ink for a given press. When dealing with inkjet inks, there are many advantages compared to analog inks. These include short-run capabilities, short response times, variability, stock reduction, local production and more.
Which ink is right for your press? Kao Collins has worked diligently to answer that question. Kao Collins has launched “InkAnswers,” a comprehensive digital search tool that matches inks with substrates used in label and narrow web production.
InkAnswers simplifies the process of identifying which inks are compatible with printhead technologies and materials, including flexible packaging, foil, shrink sleeve film, and variable facestock.
Stephen Buchanan, Kao Collins inkjet business manager, says, “It’s the right time for InkAnswers because the number one question we hear converters asking is ‘What inkjet ink should we use for this substrate?’ There are many variables when choosing inks. It gets complicated quickly.”
InkAnswers offers quick results for some of the most common printing needs such as sustainability, reducing ink migration, reducing downtime and more. “We are confident InkAnswers will build more awareness of industrial inkjet printing capabilities and the versatility provided by inkjet inks and technology,” Buchanan adds.
Fujifilm’s Berritt states that picking the right inkjet partner is crucial. “The cost of failure is much higher with inkjet inks and overall quality and consistency of the product, therefore even more important,” he comments. “Printheads are very expensive and often the first to suffer with poor ink systems.”
As Xeikon’s Deprez notes, there are many factors to take into consideration. “You need, in general, three times more ink to print the same design, basically because of the jetting and the need for low viscosity, and due to the technology,” explains Deprez. “The inks are also much more expensive to make, as all the components and particles have to be smaller than 150 nm, which creates a lot of challenges in the reproducible making of stable inks.”
Due to these factors, designs with UV inkjet will always have much thicker ink layers, which can be problematic when using this technology in thin flexible packaging applications, for example. Water-based, either pure or hybrid, is generally better suited for this segment.
In addition, more is required from a single inkjet ink. “In general, one ink has to do it all. This is very different from flexo printing, where the ink is adapted to the design, the need, the substrate, the post-printing process and so on,” comments Deprez. “This is not possible in inkjet printing, where you can’t switch the ink easily. Plus, UV ink stability features very high reactive mixtures, and due to low viscosity – linked to small molecules – there is a high degree of difficulty to make these inks food packaging compliant or even low migration optimized. This is challenging when combined with the ever-changing regulatory landscape that continually limits the use of the amount of products allowed to be used for UV ink making.”
Water-based inks have the balance between no evaporation at the nozzle plate in the head (also when not printing for a long time) and the extreme drying and image quality challenges when printing on non-absorbing substrates like polymer films.
Epson’s Gomez states that the current supply chain challenges further reinforce the importance of selecting a trustworthy partner. “As the current stresses on the worldwide supply chain show, the strength of the ink supplier needs to be carefully considered,” he remarks. “Epson hasn’t had the same delivery issues as other suppliers because of the redundancy in our supply chain. Ink for our color label presses is manufactured in any of half a dozen factories in different countries. The international nature of Epson’s business also means we saw the crisis build from its early stages last year, so we were prepared when it reached North America. Other press manufacturers buy their printheads and inks from third parties – a step removed that could entail supply risk.”
Inkjet ink development is not a rote process in which anyone can partake. There is incredible science and nuance that is required.
“Ink design is not for the meek,” says Gomez. “It entails creating a formulation that performs reliably for a variety of applications and substrates. It must be stable under most storage conditions, with high-grade ingredients treated and mixed in a sophisticated manufacturing process with specialized equipment and a highly skilled workforce. The formulation must be matched with the printhead and the ink storage, circulation and delivery systems, including the printhead.
It must have a reasonable expiration horizon to withstand transport and storage, too.”
Ink improvements
As more and more converters opt for digital inkjet printing technologies, the inks have had to evolve, as well. Many of these inks must satisfy a printer’s need for more diverse applications, including flexible packaging, shrink sleeves, in-mold and so on. Traditionally, flexo inks have been the remedy in this arena.
The improvements regarding inkjet inks have been twofold: the inks and the printheads. “Both inkjet inks and printing heads have seen significant improvements,” states Xeikon’s Deprez. “The performance and life of some of the piezo printheads have improved. Print resolution is gradually moving up, and architectures are going toward ink circulation in the heads. There is also a lot of intelligence being developed to compensate for failing nozzles. These improvements will find their way toward the industrial application field in the next coming years.”
Modern printers are becoming more intricate with a vast number of printheads and nozzles that need to stay in good working order if customers are to receive a good return on their high productivity capital investment.
“Inkjet is an evolving and scalable technology but has reached the point whereby most applications can be served by the speeds, widths and image quality that can now be achieved,” says Sun Chemical’s Jackman. “Thus, the onus is on the inkjet chemistry to satisfy the end-use requirements and perform reliably in the printing phase. If these technical requirements can be achieved, and the economics fit the business model, then significant adoption is seen.”
According to Jackman, inkjet ink formulations are moving more toward water-based technology where possible, whether that is new market developments or existing UV ink applications that can now be served with the latest development in aqueous inkjet technology. “This is due, in part, to regulatory compliance for food packaging, but increased sustainability demands are also driving this trend,” he notes.
Another key trend involves the advancement and availability of LED curable inks, as opposed to mercury lamp curing. “LED has been used for pinning for some time now, but its use has expanded to the full cure in presses like the Epson SurePress L-6534VW,” comments Epson’s Gomez. “LED avoids the high temperatures that mercury lamps give off, so curing with LED obviates the need for expensive chill rollers when printing on thin (e.g., unsupported film) or heat sensitive (e.g., heat shrink) substrates. LED curing takes less energy overall. LEDs also power on and off instantly, which means there is not time wasted waiting for the traditional lamp to power up.”
For Fujifilm, inkjet inks must keep up with the surrounding technology. “Adhesion to new, challenging media is becoming an increasing issue,” states Berritt. “This is true particularly when looking at non-PVC print media such as polystyrene and polypropylene.”
New products
As Epson’s Gomez notes, “Ink design is not for the meek.” Suppliers have worked tirelessly to optimize ink sets to thrive with many of the latest digital printing presses and printers. When selecting Epson, converters have the advantage of working with a manufacturer that develops its own inks, which provides company expertise, economies of scale, and technology to keep expanding its offerings.
“The SurePress L-4533AW uses Epson’s water-based, resin-coated pigment inks,” says Gomez. “The SurePress L-6543VW uses Epson LED curing inks. Epson invests directly in hygienic systems and processes to produce ink for its SurePress digital inkjet presses that is suitable for food applications and conforms to US FDA current Good Manufacturing Process (cGMP) guidelines and European Food Contact Materials regulations.”
Fujifilm offers a wide range of inkjet products for this market. These Fujifilm inks have been branded as Uvijet, and these inks have been formulated for a variety of systems consisting of varying printheads and curing systems, Fujifilm’s Berritt notes.
INX International Ink Co. provides a wide variety of solvent and UV inks for this market. “We carry many products for aftermarket use and others that have been designed with a customer’s specific needs or application in mind,” explains Sofia Machain, product manager-digital for INX International Ink Co. “That is the true benefit of working with us. If we don’t already have a product available, we will develop one for you that meets all regulatory needs.”
Sun Chemical remains committed to UV technology despite the tightening of the regulatory landscape, especially as UV will remain the dominant technology in labeling for years to come, says Jackman. Sun Chemical has a range of inkjet inks on offer under its SunJet brand. These include its SunJet Etijet inks for narrow web and labels, as well as its Amphora range for packaging. Where applicable to food packaging, both ink ranges are manufactured in accordance with good manufacturing practices and formulated in line with guidelines for food packaging applications.
Amplio falls under Sun Chemical’s SunJet brand and is a full range of digital effect solutions. The range comprises gloss varnishes, cold foil adhesives, lamination adhesives and varnishes for digital effects. These are primarily used for folding cartons for luxury goods such as perfumes and cosmetics and high-end labels requiring embellishment with tactile effects and metallic foils.
“Sun Chemical’s UV inkjet solutions are continually being reviewed to ensure compliance with regulatory updates that encourage cleaner labeling of UV ink for labels and improved product performance,” says Jackman. “Sun Chemical recognizes the importance of the total process in packaging. The application of inkjet inks, in conjunction with primers, adhesives and varnishes, is essential to meet some packaging requirements. Sun Chemical’s SunEvo range of coatings can help printers and converters of flexible packaging, paper-based packaging, narrow web and labels, folding carton and corrugated unleash the full power of digital printing.”
Xeikon, in partnership with parent company Flint Group, has developed UV inkjet products for its Panther Series presses. The inks feature durable performance, stability and compatibility with most label substrates. “These inks meet the demands of brand owners for high gloss and durable labels with high scuff resistance,” notes Xeikon’s Deprez. “The Panther DuraCure UV technology produces high gloss effects that stand out across the widest color gamut while delivering outstanding long-term durability for multiple applications.”
The inks have been optimized for multiple end uses, including industrial, chemical and household labels, as well as high-end labels for the premium beer, beverage, food, and health and beauty market sectors. For a water-based option, Xeikon offers Idera, which adheres to food/migration compliancy and is also Swiss and Nestlé list compliant. This ink displays a good balance between open time and drying, and compatibility with many corrugated substrates. It has been engineered for coated and uncoated materials, in general with the aid of a primer.
The advanced capabilities of Xaar’s Ultra High Viscosity technology demonstrate the difference that inkjet printing can make to labels and packaging, the company says. Part of Xaar’s ImagineX platform, Ultra High Viscosity technology ensures Xaar’s printheads deliver high impact, and productive and efficient results for volume digital label and packaging printing applications.
By enabling an extended high color gamut and fluids with larger particles and more pigment, colors are more vibrant, and whites and blacks are stronger. The ability to print high opacity, especially whites, in a single pass is useful for delivering impact on many labels and direct-to-shape package printing applications, as well.
In addition, fluids and inks with viscosities of up to 100 centipoises (cP) can be jetted in a single pass, further opening up opportunities for label and packaging printers to deliver new and exciting finishes for clients across a wider variety of packaging materials, with a high degree of efficiency and productivity.
Energy is also saved because UV fluids, which previously required heating to 45 degrees Celsius before jetting, can now be laid down at room temperature. Overall, less fluid is required, making the process even more sustainable.
Further, high-build varnish embellishments can be achieved more easily to add texture, visual impact, and functionality (such as ink that resists cracking on flexible surfaces) to labels and packaging. From Braille and tactile warning triangles on labels, to the latest haptic effects for a high-end look and real shelf presence for rigid and flexible packaging, with Xaar’s Ultra High Viscosity technology, results can be achieved that have traditionally only been possible by using screen printing.
Graham Tweedale, general manager of Xaar’s printhead business unit, says, “We are already seeing how Ultra High Viscosity technology is opening up new possibilities for Xaar in a number of applications, particularly labels and packaging. Whereas previously inkjet printheads have typically been only able to jet fluids of around 8 to 12 cP, our technologies enable printers to jet much higher viscosities, achieving a wider color gamut and unparalleled opacity, and can be used to print an extensive range of special effects.
“In addition, after many years of requests from clients to be able to print higher molecular weight photopolymers to increase resistance and flexibility for printed materials, our Ultra High Viscosity technology has realized this capability, truly unleashing the power of inkjet,” he adds.
Ultra High Viscosity technology is available across many of Xaar’s printheads, including the Xaar Nitrox, the 50x series, and Xaar 2002.
