Understanding The Impact Of Digital Printing On Flexible Package Laminating

By Joe Spinnato, Ph.D., Regulatory Compliance Manager, Ashland Specialty Ingredients and Cindy Fruth, Industry Manager, Laminating & Coating Adhesives, Ashland Specialty Ingredients

Digital printing is an emerging print technology for flexible food packaging that’s enabling brand owners and converters to effectively deliver shorter run lengths, improve shelf appeal, and meet speed-to-market demands. There are several digital technologies in the market, but presses that require attention to detail regarding the packaging design, especially the adhesives, are emerging as the dominant technology. Selecting the proper laminating adhesive is imperative to the integrity of the packaging structure, preventing tunnels, leaks, and other packaging defects. It also impacts the substrate choice, which will affect chemical migration.

Three Adhesive Classes

There are three classes of laminating adhesives used in flexible packaging, all of which can be used with flexible food packaging.

Water-based adhesives offer outstanding environmental profiles with adequate performance for the vast majority of food packaging applications. They can be based on modified urethane technology or other chemistries and may be one- or two-component systems. They offer low VOC content, immediate bond strength, and can be used on high-speed lines. They can deliver superior clarity, resistance to the average heat used in pouch-making processes, and resistance to aggressive ingredients.