33—FACTORIAL STUDIES IN ROTOR-SPINNING PART I: COTTON YARNS

Abstract

An investigation is described in which the effects of several factors, such as rotor diameter and rotor speed, twist multiplier and yarn twist, and type of draw-off nozzle, were studied in factorial experiments in which measurements were made of the main yarn parameters, such as tenacity, elongation at break, and regularity, and of the trash accumulated in the rotor. The experiments were made for cotton on two types of machine. Süssen and SKF. For twist values remote from the optimum twist, the linear and quadratic components of the twist multiplier affect the yarn tenacity, and its linear component affects the elongation at break; but, for values close to the optimum twist, the only significant effect is the linear influence on elongation at break. Yarn irregularity is significantly affected only by the twist multiplier. The rotor speed affects the tenacity, elongation at break, and yarn irregularity in a linear manner, but the rotor diameter affects these parameters both linearly and quadratically. The type of draw-off nozzle has only a slight effect on tenacity, whereas trash accumulation in the rotor is influenced by the linear components of both the twist and the rotor diameter. Some significant interactions were detected, which principally affect elongation at break generally, and trash accumulation in the rotor and tenacity when one of the interacting factors is the type of draw-off nozzle. The two machine types produced concurrent results.