UV inkjet printing is one of the predominant imaging platforms in wide-format graphics production, thanks to the health and safety advantages UV inkjet inks offer over solvent-based inks, their high productivity with nearly instant curing and superior adhesion, and the compatibility they offer with a broad range of media. But some of the properties that make UV inkjet such an attractive option also impose limitations in inkjet's technical capabilities. By carefully altering the formulations used, UV inkjet has many potential uses as an alternative to time-consuming, manual decal decoration and airbrush painting in industrial thermoforming applications.
While the market potential for converting these types of applications to digital printing is attractive, the status quo in inkjet ink development emphasizes difunctional, high-crosslinking acrylates that cannot withstand the heat, pressure and elongation needed in the thermoforming process.
By carefully examining the role monofunctional acrylates can play, the industry can develop a potentially important new niche for custom printing of industrial and packaging products using inks that can withstand superior elongation under high-heat thermoforming conditions. Monofunctional acrylates enable UV inkjet inks to be flexible enough to meet or exceed the percentage of elongation possible with the underlying substrate. Rethinking the color pigmentation process, augmenting inks to develop process colors that don't change under heat and don't fade when stretched, helps to complete this important technical innovation.
This paper will highlight the essential development concept behind this new type of highly flexible ink: a patented formulation EFI acquired in 2014 and uses in its VUTEk GS Pro-TF products.