The Influence of Moisture, Temperature, Pressure Pulse and Substrate on Print Quality in Flexographic Printing

Abstract: Flexographic printing is a common printing method for package printing. It is primarily the flexible printing plate and the low viscosity inks that characterizes flexographic printing, and make it possible to print on a variety of substrates. One drawback of flexographic printing has been limited print quality. However, substantial progress has been made in print quality and flexography is now competing with offset printing in certain fields.



The objectives of this study was to obtain further knowledge of the most important mechanisms of flexographic printing and how they influence the print quality. Several printing trials were performed with water-borne inks in a full-scale flexographic central impression printing press. The results of the printing trials have been evaluated in terms of chemical interactions between the ink and the substrate and in terms of contact mechanics of the ink transfer in the nip between the ink-covered printing plate and the substrate. Uncoated board and liner were used in the printing trials.The effects of different printing press parameters on print quality have been studied: uptake of water by the substrate originating from the water-borne ink, surface temperature on the running paper web, printing pressure, printing speed and printing plate material.