3—FACTORIAL STUDIES IN ROTOR-SPINNING PART II: POLYESTER-FIBRE AND POLYESTER-FIBRE-COTTON BLENDED-FIBRE YARNS

Abstract

An investigation is described in which the effects of factors such as the rotor speed, the design of the draw-off nozzle, and the yarn twist were studied in factorial experiments in relation to yarn parameters (tenacity, elongation at break, and irregularity) for 100% polyester-fibre rotor-spun yarns and 50–50 polyester-fibre–cotton blended-fibre yarns. An SKF machine was used. It is shown that the effect of the type of draw-off nozzle on yarn properties is more prominent for polyester-fibre yarns than for cotton yarns, probably owing to the twist levels used. The rotor speed continues to influence all yarn parameters strongly. The behaviour of polyester-fibre–cotton blended-fibre yarns resembles that of all-cotton yarns more than that of all-polyester-fibre yarns. In the experiments carried out, a few interactions were evident at significance levels of 5%, and most of these concern the type of draw-off nozzle in polyester-fibre–cotton yarns.