Roller Nip Behavior with Fountain Solution.

A simplified theory to predict the variation of fluid-film thickness on a roller as a function of slip ratio between rollers is presented. The theory is validated by experiments to determine both film-split ratio and the quantity of fountain solution that will pass through the nip between a metal and a rubber-covered roller. Experimental variables include roller hardness, speed, slip ratio, loading and fountain solution composition. The results are presented in terms of the film thickness that would be delivered to the plate by a dampener.