Experimental and theoretical study of web traction over a nonvented roller

Abstract

The traction developed between a thin flexible web, wrapped around a nonvented, rotating cylindrical roller is studied experimentally and theoretically. A series of eight webs representing a wide range of surface roughness characteristics are traction tested against the same roller over a wide speed range. A one-dimensional finite difference model that couples air film pressure (Reynold's equation), web bending and solid-body contact using an asperity compliance function is used to model the experimental traction data. An optimization technique is used to estimate the asperity compliance function parameters. A new model for computing the asperity engagement height for non-Gaussian surfaces is presented when the roughness of both surfaces is taken into account. Results are presented which indicate the viability and utility of the new methods.