Energy curable inks – UV, UV LED and EB – have made plenty of gains in recent years, but there remains much room for the technology to grow in the graphic arts market.

Ed Dedman, Zeller+Gmelin’s flexo technical support/product manager, recalls a time – “Even 15-20 years ago,” he said – when it was a widely held belief that UV would become the “predominant” chemistry/technology in the narrow web industry.

“But here we are, still splitting use between water-based and UV, while the litho industry still runs a ton of work with conventional inks,” he said. “I think UV has found a majority of use in specific niche markets like shrink sleeves and flexible packaging, and I would expect that usage to continue to grow as low migration applications for UV/LED/EB become more common.”

“What is most surprising about the growth of energy curing has been its adaptation in food packaging applications and versatility to be used in virtually all printing applications,” added Tony Renzi, VP, product management packaging inks, North American Inks, Sun Chemical. “UV has found a position in packaging, commercial, industrial and more. And it can be used for a variety of printing processes, including offset, flexo, screen, digital, etc. Variations of energy cure are the future of printing.”

Dave Hiserodt, president CUSA at Siegwerk, said, based on UV printing’s benefits, he’s not surprised how far the technology has come.

“UV printing offers convincing benefits like fast curing speed, surface flexibility, high print quality, durability and no emission of volatile organic compounds (VOCs),” he said. “Thanks to the fact that UV inks dry in a matter of seconds, the printed material can be immediately processed when coming out of the press, which saves printers money and time.

“Besides, UV printing can be used with almost any surface, absorbent or not, and, therefore, offers printers and brand owners a vast selection of inflexible and flexible print substrates,” he continued.

“It doesn’t only offer time- and cost-efficient benefits but also can add special value to prints, for example with high-gloss metallic inks in order to stand out from others. It has its reasons that UV printing is already one of the dominating technologies used in narrow web and mid-web printing in some regions, whereas UV printing remains a growing market with sustained future potential in other regions around the world.

“Going forward, an increase of the profitability for long runs and availability of ink solutions optimized for newer UV equipment will lead further printers to opt for energy curing for their full range of print jobs,” he concluded.

“We’ve seen steady growth and evolution of energy curable technologies over the last couple of decades in offset packaging, narrow web labels and commercial markets,” said Niklas Olsson, global brand manager narrow web, Flint Group. “Most recently, UV LED technology has started to make a strong impact as converters are interested in productivity gains, improved printing capabilities, lower total cost to print. We also see that the environmental impact is growing of importance and UV LED offers significantly lower energy consumption.

“The ability to use an expanding number of substrates and use LED technology by retrofitting existing presses will continue to expand the number of printers using this technology,” Olsson added.

UV LED is making headway in the energy curing space.

“With its potential for eco-efficiency, cost-effectiveness and productivity advantages, LED UV is definitely one technological advance of recent years that will drive future development in the ink industry,” Hiserodt said. “Besides, LED UV offers optimal cure speed and consistent UV output removing rejections. It’s not uncommon for long-run applications to hear about 200-300 fpm faster press speeds with LED involved.”

“LED UV technology offers substantial energy savings of about 60% compared to conventional UV systems that use mercury vapor lamps,” said Hisayuki Abe, president and CEO, Toyo Ink America, LLC.

“Other advantages include low heat generation for use on temperature sensitive substrates, no VOC generation, and immediate availability of UV power without a system warm-up.”

Kazuhiko Shigesu, manager, global business management, T&K Toka, shared four advantages: Lower energy cost than regular UV; instant or partial switch on/off; lower heat; and good use with film substrates.

“The biggest advantages for LED UV curing are primarily reduced energy costs, reduced on-press maintenance, faster run speeds and better through cure – especially for opaque whites,” Dedman added. “[B]ut from our perspective one of the often-unnoticed benefits is the consistency of energy output over the life of the curing unit, which will help resolve one of our most common technical challenges – old bulbs and dirty reflectors.”

Energy curing technology continues to grow in the graphic arts market. But faster growth can still be spurred.

“[This] will require further investment and the successful development of new equipment and materials in terms of performance and cost,” Abe said.

Shigesu said it could happen with new LED-UV or EB equipment that produces a higher output at a lower energy consumption along with more collaboration with digital.

“Certainly, both new equipment/technologies and better ink formulations will help fuel continued growth of UV/LED and EB curing, but I’m concerned that the issues with PI (photoinitiator) supply and increased regulatory pressures may serve to limit that growth,” Dedman said. “For printers who have older presses equipped with conventional drying systems, that’s an easy answer when confronted with rising costs of energy curable inks; just keep printing conventionally until the situation changes.”

“Two key things need to happen to spur the faster growth of energy curing technology – meeting the various regulatory requirements across the globe and R&D,” Renzi said. “Energy curable inks have faced increased regulatory scrutiny in recent years. Worries in the marketplace exist that some photoinitiators are unsafe for food packaging. In some places, such as California, certain photoinitiators may create other challenges.”

As mentioned, photoinitiators have been a huge problem in terms of supply and availability.

“Photoinitiators were one of the most affected raw material groups of China’s Blue Skies initiative,” said MaryEllen Maxwell, regulatory director, Flint Group. “Supply became increasingly tight, with raw material suppliers raising costs and putting some customers on allocation. Unrelated events in Europe exacerbated the situation: some widely used photoinitiators and synergists were reclassified as Category 1B H360 Reproductive Toxicants by the European Union REACH/CLP program. Although these materials are not banned from use, the European Printing Ink Association’s (EuPIA) Exclusion Policy prohibits substances and mixtures classified as 1B Reproductive Toxicants be used in the manufacture of printing inks. EuPIA since acknowledged the photoinitiator shortage and temporarily allowed for a continued use in Europe, provided that safe use can be demonstrated by adequate risk assessment.”

“Many photoinitiators or the intermediates are sourced from China,” Renzi said. “Government-led environmental assessments have caused many suppliers of photoinitiators to either cease or reduce production for extended periods of time.

“Additionally, photoinitiator supply has also been impacted by major incidents, including explosions, fire, unforeseeable events, low inventory levels, unplanned turnarounds and various production outages,” he added. “Supply continues to be in a crisis mode while prices are increasing at double-digit rates.”

“The whole industry is still suffering from the critical supply situation and the corresponding price hikes of various raw materials. Prices have been at noticeably higher levels throughout 2018 and we don’t expect any significant relief in the near term,” Hiserodt said. “Due to stricter environmental regulations put in place by Chinese authorities and unexpected plant closures, prices for pigments, relating intermediates, photoinitiators as well as other additives, have also increased significantly during 2018.”

“We have had to make alternative ink formulas and are asking customers to qualify the alternates,” Dedman said. “Industry suppliers are working to get production back online as best they can dealing with new regulations in the EU and China where most PIs are made.”

And the forecast doesn’t look good, either.

“The best information we have is the shortages will continue through the end of the year and possibly longer,” Dedman added.

According to Maxwell, Flint Group is proactively reformulating affected products to replace the reclassified materials with non-Cat 1B alternatives. “Unfortunately, she said, “those alternative materials are significantly more expensive.”

“Further growth of LED UV will depend on legislation and on the availability of a full range of inks and varnishes enabling the use of LED UV for all kinds of printing applications,” Hiserodt said.

Despite all this, the graphic arts sector is a strong area of growth for UV and EB curing. Those in the industry have taken notice.

“The overall UV/EB market is still growing while the development is heavily depending on the regions,” Hiserodt said. “In EMEA, UV is already by far the dominating technology for narrow web and mid-web printing and we don’t expect the growth to further heat up. Emerging markets such as Eastern Europe grow faster than, for example, Central or Southern Europe. In the US, we see further growth potential for UV curing especially in the digitization of the flexo printing process with automatic registration, LED instant on/off curing, heated aniloxes or inline LAB color measurements.

“From an application point of view, we notice an increase in flexible packaging applications being produced on narrow web presses as well as further growing demand for all kinds of low energy systems, especially for sheetfed offset printing,” he continued. “We see driving forces in all things that can really start taking downtime out of the equation to reach down and grab shorter run work while at the same time make longer runs more profitable. We don’t see any constraints from the ink side as inks and coatings are already there, for the most part, further accelerating in performance for newer LED equipment. As we show with our newer dual curing lines that react with both mercury lamps and LED UV technology, energy curing inks are getting stronger offering even faster cure and better plate durability.”

“Stringent environmental regulations on a global scale have been driving the demand for eco-conscious inks,” Abe said. “UV curable inks and coatings are known for improving air quality as they do not emit VOCs.”

“We’re seeing continued growth in the use of UV and EB curing, although EB is still moving somewhat slower than expected,” Dedman said. “[This is] likely due to the still high cost of the equipment and consumable gas needed for operation. The bigger growth area for EB will likely be in wide web flexo for food packaging. In the narrow web label and packaging arena, conventional UV is still the go-to technology, but interest in LED seems to have ‘turned the corner,’ with much more movement than even six to 12 months ago. LED adoption in the litho arena is becoming the norm.”

Industry experts have witnessed an increase in the use of energy curing for food packaging, but note there are regulatory challenges to overcome. According to Hiserodt, there has been only a “slight increase” for UV for food packaging.

“While in EMEA, UV/EB curing is already state of the art for food packaging for narrow web and mid-web applications,” he noted, adding there’s an ‘increasing’ interest in wide web applications for UV with inertization or EB.

“Overall, the US remains rather stagnant in comparison to Europe in this area with the primary factors being low-cost energy as well as looser regulations, which has maintained larger portions of conventional water- or solvent-based inks for printing food packaging,” he continued. “Even though we have seen a lot of clients in the US beginning food packaging efforts with low migration inks, they are still pushing jobs back to conventional presses as soon as the jobs get larger.”

Low migration inks are being employed for paper milk carton packaging, Shigesu observed, while Toyo Ink’s Abe noted that there is an increased demand for low migration inks in the packaging of food, beverages and other consumer goods.

“Ink makers are under growing pressure to comply with Swiss Ordinance, REACH and the health and safety regulations of brands themselves,” Abe said. “The challenge is developing products that are both compliant and high performing.”

“One of our biggest challenges is the increasing pace of new regulations in both the EU and US, including regional regulations like California’s Proposition 65,” Dedman said. “Materials are not always registered in both the EU and the US, so products developed for one market can’t always be sold in the other.”

“Nevertheless, we see this as a beneficial development for UV in the US overall beginning to break new ground,” Hiserodt said.