Examination of printability parameters of IPA free offset printing

Abstract

• Fountain solution system in offset printing system has significant impacts on the printing quality and fountain is the indispensable part of this system. The most important chemical added into the fountain solution is isopropyl alcohol. Fundamental features of isopropyl alcohol are reducing surface tension and adjusting and stabilizing pH. However, in the course of time, the disadvantages of using alcohol have emerged. In the present study, the quality levels of IPA-based and IPA-free offset prints were compared. Specially designed test scale printing was carried out after IPA-based and IPA-free fountain solutions were prepared with the same ink on matt-coated paper under optimal printing conditions. Densitometric and spectrophotometric measurements were carried out on the prints and it was ensured that they were printed in accordance with ISO-12647-2:2013 offset printing standards. Special test scales that were printed were read through scale readers and colour profiles were obtained. Comparisons were carried out on the obtained IPA-free and IPAbased printing colour gamut. Microscopic images of the smallest dots were taken and edge sharpening was examined. Print brightness measurements were carried out for the selected areas on the test scale. The study practically demonstrated that printing performed by using IPA-free fountain solution produced a better and wider colour gamut, edge sharpening was better in the IPA-free systems as the number of prints increased and the prints made by using IPA-free fountain solution were brighter.