Prediction of Litho Press Problems from Phase Equilibria of Inks and Fountain Solutions

It is proposed that the steady state ratio of ink to fountain solution present at the litho plate image gives rise to various types of phase equilibria. Each of these can be identified with various press problems as well as the water balance range from scumming to washout. This ratio is also affected by the nature of the plate, the ink, the fountain solution, and the paper, as well as the speed of the press and the coverage of the form. The effect of these variables is also examined qualitatively with a simple mass flow-rate balance. variables is also examined qualitatively with a simple mass flow-rate balance.