Friction and Lubrication of Synthetic Fibers Part IV: Effect of Fiber Material and Lubricant Viscosity and Concentration

Abstract

The effects of fiber material, lubricant viscosity, and concentration on friction of multifilament yarns are presented. Under conditions of good wetting, friction is independent of lubricant viscosity in the boundary region, but highly de pendent on lubricant viscosity in the hydrodynamic region. In contrast, under conditions of poor wetting, friction is independent of lubricant viscosity in both regions. Friction levels off to a plateau at a lubricant concentration of 0.5% weight on fabric (wof). The dominant factors in boundary tubrication are the geometry and wetting of the sliding surfaces, whereas in hydrodynamic lubrication both wetting of the sliding surfaces and the viscosity of the lubricant are of eyual importance.