Measurements of the Axial Force Required to Drive an Oscillating Roller Under a Wide Range of Conditions

A program of tests is reported on in which the initial objective was to determine the force required to cause a resilient inking roller, running in contact with a metallic roller, to move or slide in the axial direction. The variables investigated included ink film thickness, circumferential roller speed, hardness of the resilient roller covering, pressure setting or stripe of the roller, and viscosity of the ink. The results obtained are directly applicable to the design of mechanisms for driving an inking roller in an axial oscillating motion. Beyond that, the data sheds considerable light on the phenomena taking place in the nips formed by inking rollers and on the properties of typical printing inks in such nips where the rates of shear are in excess of 10,000 reciprocal seconds. Byproducts of this work include a measure of the relationship between radial force and roller stripe for three different roller hardnesses, a comparison of Laray apparent viscosities viz-a-viz actual apparent viscosities in an inking roller nip, and a comparison of actual ink film thicknesses on an inking roller versus those measured with a wet film thickness gauge.