The Influence of the Twist Direction on the Physical Properties of a Plied Yarn in a Rotor Twister

The influence or the twist direction on the physical properties of a piled yarn is studied. Theoretically, a plied yarn should have a better performance before exceeding the twist limitation when a singles yarn and a plied yarn are being twisted. In this case, the twist direction of the plied yarn was opposite to that of the singles yarn. The singles yarn is partially untied in the twisting process and influences the physical properties of the plied yarn. In this study, the influence of the twist direction on the physical properties of plied yarn in the latest successfully developed rotor twister is discussed. From the experimental results, before exceeding the extreme limit of the twist, a Z-twist-direction plied yarn made from Z-twist-direction singles yarn has 24–61% higher strength, 42–88% more elongation, 5–60% higher twisting tension, a lower twist CV%, and a higher elongation of twisted yarn than an S-twist-direction plied yarn based on the same linear density of 29.5-tex ring-spun yarn.