HEATSET OFFSET DRYING ON LABORATORY AND PRODUCTION SCALES

This article examines the results of both laboratory and industrial sc ale test printings and heatset dryings and the connections between the m. The purpose of these tests was to acquire new information about the drying of inks on different papers in order to optimise heatset dryin g. The papers and inks used in this study were selected broadly to cov er the papers and inks generally used in heatset offset printing. The drying result was analysed in terms of solvent retention, roughness, r ub-off, density and gloss measurements and a subjective pair compariso n. New measurement methods were devised. The results of the measuremen ts were used to assess the significance of both paper and ink in heats et drying in relation to drying temperature. The solvent retention mea surements showed that the drying of print depends very much on the cho ice of the paper-ink combination. According to the measurements, each paper is characterised by its own specific temperature-dependent dryin g curves in terms of solvent retention, gloss, rub-off and roughening. With new kinds of printing inks the print dries with less energy and the gloss of the print is better.