A COMPARISON OF THE THEORY WITH THE EXPERIMENT OF THE VISCOELASTIC BEHAVIOR OF ROTATING RUBBER-COVERED ROLLES

Abstract

The nip width and the driving torque were measured during rotation of metal and rubber-covered rollers under dead weight and with constant peripheral speed. The characteristic values of mechanical model of the cover were also decided from the measurement of the dynamic modulus and tan δ of the rubbers, and a comparison of the dynamic mechanical characteristic of model with them was made.Comparing the experimental results with the calculated ones using the method explained in the previous paper, the following conclusions were obtained:(1) In our test apparatus the center distance between the rollers changes with peripheral speed, particularly when soft rubber is used. Thus our theory is compared with the experiments of hard rubber-covered rollers.(2) The nip width during rotation is smaller than that of standing still, and it decreases with an increase in peripheral speed.(3) For soft rubber-covered rollers the rolling friction increases with an increase in peripheral speed, and for rollers covered by hard rubber it is constant or decreases in the high range of speed.(4) The experimental results do not coincide with the calculated ones. The disagreement is considered to arise from the fact that the characteristic values of mechanical model are decided on the basis of the measurement of the dynamic modulus of the cylindrical test pieces, where the free deformation of the test piece is allowed.