Ink Transfer and Refusal Mechanisms in Waterless Offset Printing

摘要

This study investigates the two possible mechanisms of ink refusal by the non-image area of waterless offset printing,i.e.,the formation of a weak fluid boundary layer on the non-image area and the softening of the non-image area after contacting with ink.FT-IR-ATR,Micro-Indentation,AFM and a Deltack Printability Tester were used to analyze the plate surface before and after the plate-ink contact.Our results show that the dominant ink refusal mechanism is the softening of the non-image area caused by the possible diffusion of low molecular weight hydrocarbon components in ink diluents into the polymeric layer of the non-image area.The formation of a weak fluid boundary layer is also likely to contribute to ink refusal and may play a synergistic role.