Frictional Properties of Filament Yarns and Staple Fibers as Determined by the Stick-Slip Method

Abstract

This paper describes instruments for measuring the forces involved in the stick-slip process in filament yarn friction and the forces between staple fibers during drafting. Electrical strain gages and high-speed recording instruments have been incorporated into testing equipment to furnish an accurately recorded measurement of the rapidly fluctuating forces which may occur during motion of yarn or fiber samples. Details of calibration and performance are given, together with typical tests illustrating the wide range of results observed. A simple equation has been employed to assign a numerical value to smoothness of fiber movement. Both static and kinetic values of friction can be obtained from a single stick-slip cycle.