One of the hottest topics these days is packaging, and to take an in-depth look at the technical requirements of packaging, Radtech held its inaugural UV+EB Packaging Conference last week in Philadelphia. Attracting a broad mix of packaging printers and converters, would-be converters, and brandowners like Nestlé, Nike, and Pepsico, the event focused on food packaging, offering the latest research on ink migration, details on upcoming changes to food packaging regulations, and new ink formulations. A special session presented by the Foil & Specialty Effects Association (FSEA) complemented the main track. It was a day filled with both top-level trend commentary and in-depth research reports. Radtech’s emphasis is on energy-curing inks—ultraviolet (UV) and electron beam (EB)—and those ink technologies were what the bulk of the sessions concentrated on.
The day kicked off with “UV LED Low Migration Laminating Adhesives for Flexible Packaging,” presented by Jennifer Heathcote of Phoseon and Jake Staples of Ashland, which evaluated the overall flexible packaging market, citing Smithers Pira data that flexible packaging is slated to be a $980 billion market by 2018. The flexible packaging market is one that continues to evolve, with some of the latest drivers being consumer preferences for convenience and—at least in terms of food packaging—single-serve packages. A lot of the ink action has been in UV, with LED UV in particular gaining traction. The advantages of UV LED inks are myriad, including such things as instant cure, lack of volatile organic compounds (VOCs), image quality, and more. However, one of the biggest issues with these new inksets—or any ink used for packaging—is migration, or the extent to which materials in the ink penetrate through the substrate into the food itself. Such contamination can affect the odor, the taste, or even the safety of the food being packaged, so migration assays are vital parts of the food packaging process. Heathcote and Staples detailed the methodology and results of an Ashland study on migration using LED UV inks in conjunction with various adhesives and substrates.
Ink migration will be affected by a variety of variable conditions, including the type of food being packaged (be it fatty, acidic, dry, etc.) and the conditions under which the package will be held (how long the food will be packaged and the temperatures to which it will be subjected). By replicating the food type and the packaging conditions, food packaging providers can quantify the level of migration of the various ink components—oligomers, photoinitiators, etc.—and determine if they are within acceptable and safe levels. (The FDA and other regulatory bodies set these limits.) Ultimately, it is the food packaging provider who is responsible for ensuring that food packaging is safe. The trick is that there is no one combination of substrate, adhesive, and ink that is suitable for every food type, so ongoing testing is a must, with inks and substrates tailored to specific applications. “There is no silver bullet,” said Staples.
When it comes to energy-curing inks, UV gets the bulk of the spotlight and electron beam (EB) inks, which have been around for decades, often get short shrift. But EB inks are proving increasingly useful for packaging applications. Im Rangwalla of Energy Sciences Inc. (ESI) detailed the latest developments in EB inks for flexible packaging. It should come as no surprise that digital applications are emerging (there is an EB ink available for HP Indigo, for example), but EB imaging systems are available for offset, flexo, and gravure packaging printing lines, offering speed, fast cure, less waste, and high quality. “EB curing for flexible packaging is growing,” said Rangwalla, “and digital printing is not far off.”
Jo Ann Arceneaux of Allnex USA offered the results of Allnex’s development of water-based energy-curable inkjet inks, defining the requirements for any inkjet ink—stability, filterability, jettability, resolubility, reactivity, adhesion, and resistance—and demonstrated how new energy curable polyurethane dispersions (EC PUDs) meet the criteria for inkjet applications and are suitable for food packaging applications as well.
Safety and compliance are perhaps the most important issues for food packaging providers, and while regulatory agencies like the FDA offer fairly strict guidance, it is brandowners that often have to navigate the myriad international regulations regarding food safety. One of those brandowners is Nestlé, with more than 2,000 brands worldwide. Like many big brandowners, Nestlé has a diverse packaging portfolio encompassing many different kinds of packaging for many different kinds of food products. Amaury Patin from the Nestlé Research Center detailed the challenges that brandowners face when it comes to food safety: the chemicals involved in both ink and substrate (there can be more than 10,000 of them, Patin said), the difficulty and logistics involved in testing them all, the variety of packaging materials (plastics, paper and paperboard, metal, etc.), the lack of harmonized regulations worldwide (FDA vs. EU), and the complexity of the supply chain (Nestlé does not print its own packaging but relies on suppliers and providers).
The solution that Nestlé has adopted—and which has been adopted by other food brandowners—is a multidisciplinary approach that starts with what has become the European standard for food packaging inks: the “Swiss Ordinance,” a list developed by the government of Switzerland (Nestlé is a Swiss company) of approved inks for food packaging. Complementing the Swiss Ordinance is the Nestlé Compliance Note on Packaging Inks, which stipulates that packaging suppliers and providers must only use materials included in the Swiss Ordinance, as well as provide certificates of compliance. (Much of this rigor was the result of a 2005 product recall when IsopropilThioXantone [ITX], a photoinitiator used in packaging ink, was found to have contaminated cartons of Nestlé’s baby milk brands.)
These safety requirements also form a backdrop to new developments in packaging, Patin added, such as digital printing, which enables such opportunities as variable data, regionalization and customization, “limited edition” packaging, and more. He also offered advice for present and prospective food packaging printers: “If you and your company are involved in food packaging and processes, you must ensure compliance of the end product,” he said. Ultimately, “you have to think like a food company.”
Food and drug law attorney Eric Greenberg then gave an update on potential regulatory reforms. While the current administration has promoted a “slash and burn” approach to regulations, the fact remains, said Greenberg, that some degree of regulation is actually good for business. “They make the playing field more level,” he said, in addition to offering the obvious health and safety benefits. Although some regulations have become burdensome, their original motivation was positive. Although it’s difficult to say what changes will be coming vis-à-vis packaging, “less regulatory activity from Federal agencies may inspire more action at the state level,” said Greenberg. And not just states, but NGOs and other players.
Complicating matters is what Greenberg identified as a general “distrust in institutions” such as the FDA. “The average person has no idea that the FDA knows what is in food,” he said. Although social media and other alarmists are warning about migration substances in food, the fact remains that the FDA (and other regulatory agencies) have very strict limits on those substances and the exposure level to those substances that is deemed safe.
Tom Molamphey of Agfa provided a survey of new UV inks and other technologies such as direct-to shape printing which are further changing the packaging landscape, and Julie Cross of Domino Printing provocatively suggested, in a session called “Are You Being Told the Truth About Food Compliant Ink,” that “‘low migration’ should be used as a relative term not as an absolute value,” she said. “‘Migration-compliant’ would be a more accurate term.”
Although food safety and migration issues took center stage at the UV+EB Packaging Conference, the aesthetics of new packaging printing technologies were not ignored. The FSEA’s track offered a survey of new foil and coating techniques and how effective they can be for brand identity. This track culminated in a session by FSEA’s executive director Jeff Peterson that summarized the results of a new study and white paper that gauged the impact of these enhancements on shelf presence, and found that things like gold foil stamping can drive consumers to purchase an unfamiliar brand as often as a name brand.