Study on the Relationships between Plastic Viscosity and Tack Value of Offset Printing Ink

Abstract

In order to find out the variation law of ink stickiness during the printing, the ink tack value under 9 different linear velocities of ink distributing roller was tested, and the relation equations between tack value and the roller linear velocity were built up. At the same time, the plastic viscosities of 8 offset inks and their tack values under 9 separation velocities were also tested. The study results showed that the higher the linear speed was, the larger the tack value was, and it would stay in a relatively high tack value (regarded as infinite tack value). Also, the printing ink having high viscosity may possess low tack value.