Sorne Dynarnical Observations of Friction Contact of Lubricated Fiber

Frictional force under hydrodynamic condition is given from area，thickness， viscosity and shear rate of lubricant fi1m. The area of lubricant fi1m has been measured experimentally in this study. Cylindrical lens rubbed with lubricated P. E. T. fiber has been observed under the optical microscope using light from stroboscope. The photographic pictures have been taken at suitable intervals of time using strobostreak camera. The following resu1ts were obtained. 1) Increase in frictinal force with increasing addition % of lubricant is explained by viscosity of 1iquid phase of lubricant. 2) Area of lubricant fi1m is given by one-valued function of viscosity，s peed and load. This is simi1ar in beha vior to the friction under hydrodynamic condition. 3) Decrease in friction with increasing speed at high speed and high viscosity is attributed to heating and slipping of lubricant film