27—FACTORIAL STUDIES IN ROTOR-SPINNING PART III: ACRYLIC-FIBRE OPEN-END-SPUN YARNS

Abstract

Abstract An investigation is reported of the effect of factors such as rotor diameter, rotor speed, and twist multiplier of acrylic-fibre open-end-spun yarn on the main yarn parameters, such as tenacity, elongation at break, irregularity, and quality index. Factorial experiments were used as the basis of the study. It is shown that, except for the influence of yarn twist, owing to the different characteristics of twist–strength curves and twist–elongation-at-break curves, the results are very similar to those from an earlier study on cotton yarns. For tenacity, the linear effects of yarn twist and rotor diameter and the quadratic effect of the latter are significant, there being no significant interactions. For elongation at break, the linear effects of rotor speed and rotor diameter and the quadratic effect of the latter are significant. There are several significant interactions. Not all of these present possibilities of being real interactions, some appearing to be chance interactions. Irregularity is significantly influenced by the linear effects of rotor speed and rotor diameter and quadratic effect of the latter. It is shown that one interaction could be real. For the quality index, the linear effects of both yarn twist and rotor speed appeared significant, but both the quadratic effect of rotor diameter and some interactions involving this parameter that turned out to be significant are possibly only chance effects.