15—the Measurement of Torque in Continuous-Filament Yarns Part I: Experimental Techniques

A torsion-balance apparatus, incorporating a photopotentiometer device and developed to study the torsional-hysteresis and torque-relaxation behaviour of both monofilament and multifilament yarns under conditions of constant tension, is described. Differences in the shape of the torsional-hysteresis curves are studied for nylon monofilament and multifilament yarns, these differences in shape are related to friction effects and to the mechanical properties of the constituent filaments.