UV/EB Inks - Take a Sigh of Relief

RadTech is moving toward making sure UV/EB inks are safe for use in food packaging. Is everyone ready for what this may bring?

EVERYONE KNOWS WHAT a fast-paced world it is out there. e-mail has made written communications instantaneous, credit cards have made spending money (you don't have) easier than ever, and some cars are now built to cruise at 180 mph. One other technology that seems to have been developed to save people time is the inception of prepackaged food stuffs. Consumers can quickly grab a packet of rice or noodles from their pantry and have a quick meal in minutes. But is all of the new technology safe?

Criminals can steal your information from your e-mails or credit cards, and driving too fast over the speed limit can amount to a nice big fine, and a hearing in front of a judge. But, should people really be worried they are hurting themselves when eating a quick meal?

No, says The RadTech Food Packaging Alliance, a self-funded group that is working toward making sure the use of ultraviolet (UV) and electron beam (EB) materials in food packaging is safe for the consumer. "We use UV/EB inks all the time in food packaging, like in cereal boxes, but always on the outside of the package because there is no migration of the chemicals," said Dr. Ron Golden, chair of the Food Packaging Alliance. "What we are currently working on now is getting FDA approval for the use of these inks with contact to food."

What they are doing

UV and EB inks are already in use with food packaging, and it is growing and will continue to grow at an astonishing rate. Ink makers want their inks purchased for more and more different applications, and that is just what the Food Packaging Alliance is working toward. "We are the catalyst to expand the use of UV/EB materials in food packaging. We have about 35 companies participating with us to make sure this happens," said Golden.

Currently, Golden, the Food Packaging Alliance and the 35 ink companies are working to establish a baseline for what the FDA will accept in designing UV/EB formulations for food packaging. But why? Why go through all of the work trying to make it safe for the use of UV/EB inks in food packaging? Why not just use another ink? Because UV and EB inks offer capabilities that others cannot.

UV and EB inks offer high gloss, chemical and abrasion resistant, hardness, versatility, and also easy cleanup factors that are all important to both the consumer and the converter. So it is very important that the FDA and the Food Packaging Alliance reach a common ground on this subject. "When looking at the broader sense of this, when we do reach a common ground with the FDA, it will definitely open up the industry."

So what really is the problem with using UV/EB inks in food packaging? The problem, as Golden sees it, is kind of a misunderstanding. He said some believe that dangerous chemicals can migrate from UV/EB products into food, to be ingested by unsuspecting consumers. But, he said, that may not be the case. The problem is, again, trying to see eye-to-eye with the FDA on allowable migration. But Golden is very positive an answer will surface, and even went as far as to say the FDA and the alliance will be in agreement by the end of this year. This is an exciting opportunity for all of those who are involved in package printing, especially ink manufacturers.

"UV and EB inks are widely used now for food packaging cartons, bags, and pouches, and they have been used widely for this for well over a decade. However, there is some interest for a fairly narrow set of applications for UV and EB products that are suitable for direct food contact," said Dr. Don P. Duncan, director of research, Wikoff Color Corp. "But there are no UV or EB products that are per se suitable for direct food contact."

Duncan explained what the FDA is looking for before it gives the okay to UV and EB materials.

"The FDA has always had the position that if a material does not significantly migrate into food (the less-than-50-part-per-billion level is the current definition of this) and does not adulterate the taste or odor of the food (the "suitably pure" test), than it is not a food additive, and thus outside the FDA's scope of jurisdiction, making it suitable for direct food contact," Duncan said. He added, "There is both much optimism and much skepticism in the industry as to whether The Food Alliance will be successful,"

"This group is working hard to get some common raw materials approved by the FDA. We are watching the developments in the industry very closely and also preparing ourselves internally by focusing our R&D efforts in developing products that will meet the [new] criteria," said Zubair Khan, technical development manager, energy curable products, Environmental Inks and Coatings.

Manufacturers unite

Will the new rules from the FDA and the Food Packaging Alliance mean it's back to the drawing board for ink manufactures, not necessarily said Bob Waddington, general manager, UVitec Printing Ink. "From an ink-manufacturing standpoint, we do not use any ingredients that are overtly hazardous or recognized as such in the manufacturing of our inks for such packaging," he said. Ink manufacturers have already taken a stand against using dangerous chemicals in their products.

"For instance, we do not use harmful photoinitiator packaging that contains benzophenone. For any packaging that would have direct food contact, pigments would need to be selected on virtue of their resistance to fats and acids and the like. If the pigments are naturally resistive to such substances, you generally do not see any migration of that particular portion of the ink film into the product in the container," said Waddington.

What's all the hubbub?

Why does it seem so important to get acceptance to use UV and EB inks and other materials in direct-food packaging? Why not just choose another product, such as water-based inks? Because, said some ink manufacturers, the laundry list of the benefits of running energy-curable inks outweighs the list of negatives.

"The primary benefits for using UV and EB inks are that the packages are extremely low in residual volatiles/extractables; that the packages are ready to diecut, form, and fill directly off the printing press; and that very high print quality can be obtained," said Duncan. According to Waddington, the high print quality comes from the fact that cured UV inks for packaging are very flexible, so they can be scored and folded without cracking or peeling.

Those "pros" of using UV or EB inks can be qualified by the consumer, but what about the converter? Are there any benefits to the printer for using these materials? Yes, said Khan. "High quality printing companies have realized the benefits of UV/EB technologies in the terms of increases in productivity, reduction of waste, and in no maintenance on the press. There is a clear benefit that UV/EB brings in high-quality process printing: sharper dots, ease of cleaning inks from anilox rolls because of no plug-ins, and no buildup on anilox rolls," Khan reported.

One of the more notable benefits of using energy-cured inks is the instantaneous drying which speeds the manufacturing process and allows for faster finishing and shipping, said Subh Chatterjee, director, advanced technology group, Sun Chemical. "The instantaneous curing improves job turnaround, allows for quicker secondary conversion which reduces inventory, and reduces print job re-runs since final print quality is known instantly," he said.

Because energy curable products contain no volatile organic compounds (VOCs), converters can avoid adding incinerators and getting permits that are required to maintain and expand their operations, Chatterjee said. "Increased concerns of global warming might force the printing and converting industry to consider using energy-curable inks, coatings, and adhesives as an alternative to conventional products that contain VOCs," said Chatterjee.

Yes, yes, yes. UV and EB inks have a long list of positives, but there has to be some downsides of using these inks. And there are, and cost is one example. "There is a higher cost point than UV and EB's conventional equivalent," said Waddington. "Also, certain water-based flexo metallics have better brilliance than their UV/EB equivalent. Rollers, chemistry, and other peripherals must be dedicated for use with UV/EB, or be subject to lengthy cleanup and changeover to conventional inks."

Other concerns converters need to be aware of when running UV/EB inks include: odor in the pressroom (different, but not greater than conventional inks), the potential for skin irritation from wet, uncured UV and EB products, and the aforementioned higher price-per-pound of UV and EB materials.

What's out there now

As already mentioned, people want what they want RIGHT NOW, and they want it better. Converters are not above this need, and Sun Chemical has recently developed a new ink technology for just such a package printer. Solarcat™ is the new UV ink technology from Sun Chemical that can dramatically improve press efficiency and production speeds. It is a cationic UV flexo ink system and is at least two times faster at curing than other products in the marketplace, according to Sun Chemical. Solarcat has the exceptional technical properties as a cured ink film recognized in cationic systems, while delivering significant improvements over existing technologies. These include higher cure speed, lower humidity sensitivity, low pressroom odor, and the absence of hazardous photoinitiator by-products.

"The creation of Solaris signals our commitment to the needs of the growing narrow-web market. With the development of Solarcat, Sun Chemical is demonstrating the commitment to building productivity, innovation, global reach, and local service," said Felipe Mellado, vice president, Sun Chemical Europe.

Khan from Environmental Inks and Coatings reported his company has recently introduced a UV flexo high-shrink ink series with more than 75 percent shrink on PVC, PETG, and OPS substrates for shrink sleeve labels. Waddington from UVitec said his company offers an "exciting array of new metallic ink products for every printing medium, UV inks for shrink sleeve application, and specialty varnishes and coatings for high-gloss low fingerprint, scanning, and security applications."

A look toward the horizon

While keeping in mind the needs of their customers, ink manufacturers are keeping their eye on what they think is important so they can offer the next up-and-coming products to their converters. For instance, Waddington sees EB as growing in the narrow-web market, because the technology can provide smaller units at a cheaper cost. Khan predicts double-digit growth in the shrink sleeve label market. And also, "We should see the growth in the digital inks using UV technology on wide format applications. Use of EB in the food packaging market will continue to grow, and UV applications involving indirect contact with food will also grow."

Duncan sees the next "hottest" thing in energy-curable inks is within the UV inkjet. "These products are in a very fast-growth mode with over 500 installed printers worldwide. UV hybrid inks have been around for a few years, but they are also still growing," he said. He also mentioned that "cooler running UV bulbs, lower cost EB units, raw materials with less skin irritation, and lower cost photoinitiators," are all future trends that will surface in the UV/EB ink world.

So, most everything in today's world is bigger, faster, better. But at what cost? Is technology really making it safer for consumers? Currently, no one really has the answer to these questions, but many are working toward a common goal: To make UV and EB curable inks safe for all: ink manufacturers, converters, and in the end, the consumer.

by Megan Wolf

Assistant Editor