The use of energy curing – ultraviolet (UV), UV LED and electron beam (EB) curing – has been enjoying strong growth in the graphic arts for many years. Key advantages, such as instant curing, low volatile organic compound (VOC) content and other environmental benefits, have paved the way for increasing use of the technology, particularly in packaging.

According to Grand View Research’s report, “UV (Ultraviolet) Curable Inks Market Size, Share and Trends Analysis Report, By Product (Free Radical, Cationic), By Application (Automotive, Medical, Publications, Packaging) And Segment Forecasts To 2024,” the global UV ink segment had $1.84 billion in sales in 2015.

“Global UV Curable Inks Market Report,” published by Allied Market Research, suggested that the UV ink market will be $3.5 billion by 2020, with a CAGR of 15.7% from 2015-2022.

“The printing industries have been facing the issues of volatile organic compound (VOC) emissions in recent years. Stringent environmental regulations pertaining to volatile organic compound (VOC) emissions and remarkable curing properties of UV curable inks would increase their adoption in the publication sector,” Allied Market Research analysts reported. “Moreover, sluggish curing properties and low-resolution images associated with conventional inks have boosted the demand for instantly curable, high quality and eco-friendly UV inks. In the current scenario, UV curable inks have emerged as an ideal alternative to solvent and water-based ink technologies owing to its suitability over a variety of substrates. UV LED inks are expected to gradually replace the conventional UV inks owing to the longer shelf life and improved energy efficiency of LED lamps.”

Ink industry executives report that they are seeing growth in the use of energy curable inks and coatings in the graphic arts.

Tony Renzi, VP, product management packaging inks, North American Inks, Sun Chemical, reported that Sun Chemical has continued to grow in the UV/EB market through 2019.

“The market for UV inks for commercial started slow but did expand with the utilization of more high energy HUV and LED type presses,” Renzi said.

“The packaging market has continued to see growth in UV and EB, especially UV flexo, narrow web, tag and label, folding carton, and other emerging applications in flexible packaging,” Renzi added. “Consumers are moving away from lamination applications and pursuing interests in EB curing for flexible packaging applications.”

Greg Burch, VP of regional operations & corporate accounts at Wikoff Color, said that Wikoff has noted a marked increase in energy-cure technologies in the graphic arts, particularly the growth of LED-curing products throughout the flexo marketplace, as well as nitrogen inerting technology.

“We expect those areas of the flexo industry to have continued growth,” added Burch.

Burch pointed out that the growth of energy-cure flexo has been driven by the numerous benefits that each technology offers, including the durability, gloss and sharp print of energy-cured ink films.

“UV flexo offers a higher gloss finish than water-based products, increased adhesion to a variety of substrates and faster press speeds,” said Burch. “LED flexo takes UV curing a step further with an even better cure using less energy and faster press speeds. In comparison to UV mercury lamps, LED lamps have a much longer life span, often lasting the life of the press. EB flexo provides the ultimate resistance and adhesion properties, which reduces the need for lamination. EB is also a safe choice for food packaging since it has the lowest migration levels.”

Roland Schröder, product manager UV at hubergroup, noted that hubergroup is seeing steady growth for UV curing systems.

“Above all, the area of high-quality and food-compliant packaging will grow globally in the future,” Schröder added. “Brand owners and creative printers drive the usage of UV curing technologies due to advantages such as fast drying, constant printing quality and higher gloss grades.”

T&K Toka’s focus is on UV inks, and Kazuhiko Shigesu, manager, global business management for T&K Toka, noted that T&K Toka is seeing increasing use of energy curable technologies in the graphic arts.
“The upward trend is centered on labels and packages,” Shigesu added.

Damon Geer, EVP, Zeller+Gmelin Corp. USA, said the UV market hasn’t grown in the past 12 months:“We believe it is primarily due to the photoinitiator (PI) shortages which resulted in price increases for UV and LED printing inks and coatings.”

Photoinitiators

The supply and cost of photoinitiators and their ingredients have been a cause of concern for ink manufacturers. While the availability of photoinitiators stabilized, prices remain high.

Geer reported that the photoinitiator shortages are less frequent than in the first eight months of this year.

“The costs increased due to both shortages and tariffs, and it stands to reason that new players will emerge in the PI market driving the prices back down over time,” Geer added.

“The availability of photoinitiators is currently stable but the prices continue to increase,” Schröder said. “The market is dependent on various influences and the situation can change very quickly.

“Some of the photoinitiators have significantly increased its price, but now that price is gradually declining,” Shigesu said. “We have only recently been able to purchase the required quantity. However, we have a concern about the price, and we are not sure how close it will get to the price in 2017.

“Regarding other photoinitiators which moderately increased its price, they are still in an upward trend, and have not entered a downward trend yet,” Shigesu added. “Now we are going to make efforts to get the price reduced.

“Regarding the photoinitiators produced in China, it seems that manufacturers are not thinking about stable supply and long-term business,” Shigesu continued. “They want to make money whenever they can. Although there is a challenge with the environmental regulations of the Chinese government, we hope that price fluctuation will be as small as possible. In addition, we will need to change purchase items drastically when regulations are imposed on photoinitiators in different countries. If it so happened, we are greatly concerned about how it will change the availability and the price of alternative photoinitiators.”

“The availability of photoinitiators used in UV chemistries are still a cause for concern when considering the current supply chain and reclassification of materials,” Ken Klug, purchasing director for Wikoff Color, said. “As China begins to clean up its manufacturing processes, existing factories are being shut down temporarily or permanently without qualified alternatives. Besides these supply chain challenges, the current reclassification efforts on PIs forces our industry to evolve rapidly. As some of these materials are no longer being allowed in food packaging, ink makers are formulating to suitable alternatives faster than the supply chain can respond, thus creating additional shortages. These challenges are expected to continue in the near future.”

“Due to the international sourcing of many photoinitiators and their intermediates, supply has continued to be a challenge for the industry, especially as prices are increasing at double-digit rates,” said Renzi. “Many suppliers of photoinitiators were forced to cease production as a result of government-led environmental assessments. Additionally, major incidents including explosions, fire, unforeseeable events, low inventory levels, unplanned turnarounds and various production outages have continued to impact photoinitiator supply.”

Energy Curing and Food Packaging

Food packaging is a growth area for the ink industry, but there are some issues, real as well as anecdotal, that are brought up with regards to UV curing. Ink industry executives noted that the technology is well suited for food packaging.

“Starting next year, we will offer our customers NewV cure, a new objective and science-based method for determining the degree of UV curing,” Schröder said. “With NewV cure, printers can test their UV print product within a few minutes and receive a clear and binding statement about the curing degree. This innovative solution will make one of the greatest risk potentials in UV printing more manageable and increase security in packaging printing.”

“Wikoff offers UV/LED inks that cure under a nitrogen blanket, thus reducing the amount of PIs used and increasing the suitability for food safety,” said Evan Benbow, Ph.D., director of research for Wikoff Color. “Wikoff also offers EB-cured offset and flexo inks, which eliminate the need for PIs and offer the gold standard for food-safe energy curable inks.”

Shigesu reported that various regulations have recently been established for food packaging in different countries and regions.

“It is necessary to use raw materials which follow the rules and clear the criteria according to the rules in each of the countries and regions,” Shigesu said. “However, in some countries, the regulation is still in the process of rulemaking, and some areas of the rule are unclear. In addition, the place where the printed materials are manufactured and the place where the final products are consumed is sometimes different, and it is necessary to carefully consider how to deal with such cases. We are working on deepening communication, by interviewing each customer, providing information and so on, in order to extract as much information as possible regarding demands from the manufacturer of the final product, and requirements in its final destination, so that we can supply the most suitable ink.”

“In Europe, low migration inks are used in a variety of food packaging applications,” Geer observed. “It’s not as common in North America, but due to some renewed concerns that aren’t as definable as UV ink manufacturers would like, more attention on the regulatory side is required when supplying energy curable inks to the food packaging industry.”

UV LED Curing

UV LED curing has been a hot topic in energy curing due to advantages in terms of performance and environmental issues.

“UV LED curing has continued to develop and expand over the last year,” Renzi noted. “Different LED products, such as LED lamps, are more useful for heat-sensitive materials, whereas mercury lamps require chilled rollers to reduce effects of heat on a substrate. LED is more prevalent in that specific area, as its infrared–free output has the ability to deliver energy to cure and keep things cool at the same time. Additionally, UV LED has a longer lifespan and performance length than mercury lamps.”

“Although LED equipment is increasing little by little, the number is still very small compared to conventional UV,” said Shigesu. “The trend of introducing LED equipment varies depending on the country or region, such as whether it is a new machine or a remodeled one, or what is being printed. For inkjet, UV LED is becoming the standard due to production efficiency and thin films.”

“Currently, the UV LED technology only permits reliable use in commercial printing,” Schröder said. “The system needs to be further developed for use in high-quality packaging printing.”

However, the 2018 shortages of key intermediates for photoinitiators for UV LED, leading to price increases when products could be sourced, put a damper on the technology.

“We were starting to see some growth in LED, but the PI shortage and eventual price increase seemed to hurt LED worse than standard UV,” said Geer. “We believe it’s just a minor setback for the industry and in time LED will regain its momentum.”

“We have seen an increased interest in UV LED curing, but the anticipated fast-paced growth has not yet been realized,” said Daryl Collins, VP of regional operations & marketing for Wikoff Color. “Although LED provides some major benefits to mercury vapor lamps, the capital expenditures related to converting curing stations has caused some hesitation among converters. Wikoff Color is committed to educating customers on all of the energy-cure options available and helping them make the best decision for their individual pressroom and customer needs.”

Increasing Interest in EB Curing

With the challenges that are occurring with photoinitiators, companies are taking a renewed interest in EB curing.

“Interest in EB curing has definitely grown over the last few years,” Renzi said. “We have seen a major adoption in food packaging applications and overall versatility that can be used in almost all printing applications. The packaging, commercial and industrial industries have adopted UV, as it can be used for different printing processes, including offset, flexo, screen, digital, etc. EB curing holds the key to the future of printing.”

“Due to the high investment costs and the limited refinement possibilities, the EB market will grow only slightly,” Schröder said. “The great advantage of EB curing is that this technology does not require any photoinitiators and thus significant migration potential is eliminated.”

“Due to the PI shortages, we were hearing printers talking and even looking into EB as an alternative, but it was conventional and water-based inks that benefited most as converting to those type products was relatively easy,” Geer said.

“EB flexo technology is the next big thing in packaging, offering the superior performance properties of energy-cure systems with a more sustainable footprint,” Collins said. “It eliminates the concerns of PIs, making it a great option for food-safe packaging and enables innovative packaging design.”