Unevenness of air-jet spun yarn in comparison with ring and rotor spun yarn made from micro modal fibers

Abstract

All unevenness parameters (overall unevenness, unevenness on different cut lengths of I m, 3 m and 10 m and hairiness) of the air-jet yarn produced from micro modal fibers spun on the J20 air jet machine using the unevenness parameters of the rotor spun and conventional ring spun yarn produced from the same fibers were compared. In order to reduce the number of input influencing parameters on the unevenness properties, the comparison was performed on yarns for the same end-use (knitting) and with an equal count of 20 tex (Nm 50). Assuming that the mass distribution in the yarns follows a normal (Gauss) curve a t-test of yarn unevenness was carried out. It was shown that the overall unevenness of the air-jet-spun yarn is smaller than that of the rotor spun yarn and is greater than the unevenness of the conventional ring spun yarn, while over larger cut lengths (1 m, 3 m and 10 m) it is smaller than in both yarns, rotor and ring spun yarns. The number of thin places in air-jet spun yarns at a sensitivity level -30 % is higher than the number of these faults in the ring spun yarn by 9.2 times and compared with the rotor spun yarn lower by 4.2 %. The air-jet spun yarn at a sensitivity level +50 % has the smallest number of thick places. In terms of hairiness, the air-jet spun yarn has a relatively higher quality.