Novel composite yarn with a wavy-network structure produced by various delivery speed ratios and untwisting factors

Abstract

Yarn structure variation and property improvement have been widely investigated for applications in fancy fabric production. Thus, a novel composite yarn was fabricated by dynamically forcing strand migrations around filaments with varied tension control, regulating the geometric configuration between the filaments and staple fibers. The geometrical principle of wavy-network structure variations of novel composite yarns caused by tension interference and helical migrations between filaments and staple fibers was theoretically analyzed. Subsequently, the coordination of delivery speed ratios and untwisting factors was applied on a ring frame with a delivery roller to control the tensile difference and spiral trajectory, which oscillated the helical convergence between filaments and strands to conduct confirmatory tests. The online observations of the convergent formation in the spinning-triangle zone were technically applied to evaluate the dynamic helical migrations between strands and filaments, and the spiral structural variations of the yarn were caused by various tension difference interference and twist tracks. Experimental results revealed that the novel composite yarn had a network structure with wavy-dense wrapping, and the yarn hairiness, irregularity, tensile, and snarling properties were successively measured to compare the yarn property improvements with other composite yarns. Generally, the systematic tensile oscillation between strands and filaments in the yarn formation zone, which are produced by various delivery speed ratios and untwisting factors, are promising as a novel method for controlling the helical configurations and inter-stress between filaments and staple strands.