EFFECTS OF OVEN DRYING AND POLYDIMETHYLSILOXANE (PDMS) EMULSION COATING ON HEAT-SET PRINTING QUALITY

Abstract

In the heat-set printing drying process, the paper is exposed to oven drier temperatures of about 120-150 degrees C, so that the solvent in the printed ink film can evaporate. The printed paper is coated with a polydimethyl siloxane (PDMS) emulsion by means of silicone rollers after drying. In this study, the influence of oven drying of the wet ink film and polydimethyl siloxane emulsion coating on the heat-set print quality parameters were investigated. For this purpose, CMYK printed coated papers were passed through a heat-set oven, where the wet ink film was dried, and then coated with PDMS emulsion. Tone value increase (TVI), color CIE L*a*b* and print gloss measurements were made and recorded by taking test print samples from each of the printing, drying and silicone emulsion coating processes. The results were discussed in terms of printability and print quality, and recommendations were made. It has been determined that oven drying reduces half-tone dot values in printed areas on coated papers. In addition, oven drying caused a significant change in black color. PDMS emulsion coating reduced print gloss, similarly to oven drying.