Fiber packing density in the cross-section of low torque ring spun yarn

Abstract

Fiber packing density in the yarn cross-section is one of the major parameters that reflect the yarn internal structure and its final properties. Taking the novel low torque ring spun yarn as the object, this work studied the fiber packing density of low torque ring spun yarns and conventional ring spun yarns under various axial tensions. With the increase of tension, the change of fiber packing state in low torque ring spun yarns and conventional ring spun yarns was compared qualitatively. In this study, fiber distribution in the cross-section of both Tencel yarns and wool yarns was carried out. The results show that, under the same axial tension, the packing density of fibers of low torque ring spun yarn is much higher than that of conventional ring spun yarn. The axial tension has greater influence on the fiber packing density for the conventional ring spun yarn. From the experimental results, in low torque Tencel yarn, the fiber packing density nearly reaches 0.9, which is the maximum value for close-packed yarn. Due to different fiber properties and yarn structure, it is difficult to form a close packing for fibers in low torque ring wool yarns. The current results indicate that low torque ring spun yarn has a more compact structure than conventional ring spun yarn. Compared with conventional ring spun yarns with the same count and twist levels, in low torque ring spun yarns, more fibers contribute to the yarn breaking strength.