Digital printing is quickly becoming a leading technology for packaging, particularly in labels and corrugated. However, ink industry leaders say there still is plenty of work to do to bring inkjet into the mainstream in packaging.

Paul Edwards, VP of the Digital division at INX International Ink Co., said that when looking outside of corrugated/narrow web and labels, there are challenges that need, and in many cases, are being addressed.

“Packaging applications often address food-related products,” Edwards said. “Thus, ink products face regulatory challenges, and regulations are dependent upon global geography and the packaging materials in question.

“For example, some containers are considered barriers to migration and some are not,” Edwards said. “Therefore, ink and coating technology must consider and address these regulatory requirements in terms of achieving indirect food contact status and ensuring factors such as odor are addressed, as well as the potential for migration. This is a significant factor within the world of flexible packaging as the substrates and applications are so many and varied.

Edwards observed that for conventional flexible packaging printing, solvent-based inks are mostly used, which differs from digital printing.

“Alternatives such as water and low migration UV/electron beam technologies are also used, but to a lesser extent,” Edwards added. “In digital printing, it is commonly considered that water-based inks are the future for flexible packaging. However, even with water-based inks, you must ensure the components are suitable for indirect food contact.

“You also have the technical challenges of providing an ink with good adhesion to the packaging materials. They must work reliably without blocking the inkjet heads and dry as quickly as possible, even though there is much more ink applied in a digital process than conventionally,” Edwards said.

Edwards pointed out that another growing area of interest is digital 2-piece can printing, although in the United States, the aluminum can is considered a barrier.

“One does need to consider the potential for the ink on the outside of the can to encounter a consumer’s lips or mouth, as well as the possibility the can’s contents may pass over the image before being consumed,” Edwards said. “UV inks are the ideal choice for this application, but they need to be designed to pass both the regulatory constraints of the region (such as Nestle/Swiss), and the relevant migration tests which are very challenging in this application.

“Overall, there are many other challenges to consider both in the design of the printing system and the inks and coatings,” Edwards concluded. “Companies such as INX are addressing these challenges by providing their customers with technical solutions which will drive digital adoption across these application sectors.”