Mixing Oil and Water: Digital Printing on Hydrocarbon-Based Flexible Films with Water-Based Inkjet Systems

Douglas Bugner and William Mansfield, Kodak (InterTech Award Recipient)

Packaging printing is a $392B market expected to grow at 2.6% CAGR through 2025, with digital printing growing at 10.1%. Printing of flexible food packaging has been trending toward water-based printing systems for reasons of health,safety, sustainability and cost. Unlike most paper-based substrates, flexible films tend to be hydrophobic and water-impermeable, which makes it a challenge to achieve adequate wetting and adhesion of water-based inks, not to mention the subsequent removal of the water and any co-solvents that are in the inks. In this paper, we will briefly review the market trends in package printing, including common multi-layer package structures, and provide an overview of the various digital printing technologies that are available today for printing on thin, flexible films, providing a summary of the advantages and disadvantages of each. We will describe in detail an all-aqueous system of primer, printing inks, and post-coatings that overcomes the limitations of current systems and can be used for either surface or reverse printing of plastic labels, flexible packages, and vinyl wall coverings at production speeds of up to 300 meters per minute.