Theoretical modeling of traction characteristics between paper-web and steel-roller based on the contact mechanics

Abstract

This report describes the theoretical modeling of friction coefficient between uncoated paper web (newsprint; for example) and steel roller. In the modeling, the paper base is approximated by the linear spring and surface asperities are treated as rigid body. Introducing the contact mechanics and assuming the Gaussian distribution of surface asperities, the mixed friction coefficient is formulated theoretically for a wide range of roller surface velocity, in which the air film thickness between the web and roller is estimated based on the foil bearing model. In the experiments, the newsprint is used as uncoated paper-web. Euler's belt formula is applied to calculate the friction coefficient from the measured data on tension increase. The measurements are carried out by changing five design parameters such as web width, wrap angle, tension, roller diameter, and roller surface velocity. The measured results are compared with the predicted results by the friction model. Good agreements can be seen between the predicted results and measured results.