Hydrodynamic Factors in the Friction of Fibers and Yarns

Many investigations of the friction between yarns (or fibers) and cylindrical pins have been described. Most of these have involved lubricants or finishing agents of un specified physical properties. Recently Lyne has described a study in which mineral oils of known viscosities have been used, and he has examined the effect of speed, viscosity and pre-tension. In this paper it is shown that his results may he explained on the assumption that, to a large extent, hydrodynamic lubrication exists between the yarn and the pin. Further experiments described here suggest that other factors, such as wetting angle may also be significant. However, the main new point brought out is the im portance of hydrodynamic factors in the frictional behavior of yarns sliding over cylindrical surfaces.