Coating Formulations for Digital Printing; Applications of Phase-Change Inks

Abstract

Hot melt/phase-change inks have gained popularity by imparting high print quality. As hot melt inks differ from other digital and conventional inks in terms of properties and mechanisms of transfer onto a substrate, there is need for developing low cost substrates compatible with these solid inks. As these inks solidify upon contact with the substrate, there is little absorption of the ink into the substrate. Thus, the print quality and associated color gamut are less sensitive to the substrate than that for aqueous ink jet printers.It is well known that the surface properties that influence the print quality vary for different printing processes. Thus, the substrate-ink interactions must be well understood. Some of the important surface properties of a substrate include permeability, porosity, surface energy, roughness, opacity, brightness and gloss. These properties are known to influence final print quality and color gamut. Adhesion of ink on paper also plays a vital role. In addition, economics play a vital role. The paper specially formulated for phase-change inks sells for about 50 ¢ per sheet in comparison to 2-5 ¢ per sheet for water-based inkjet papers. Thus, there is a need for the development of lower cost substrates compatible with solid inks.