Fiber Feeding onto the Yarn Tail in Friction Spinning

Abstract

The divergent channel in friction spinning causes fiber deceleration and inferior orientation in the transport channel. A convergent channel is designed, and the properties of yarns made by it are compared with conventional channel yams. The position of the convergent transport channel relative to the suction slit is a very important factor in improving yarn properties. The results of our research show that yams made by the convergent channel positioned 15 mm from the beginning of the suction slit are the strongest. The mechanical properties and structural parameters of friction-spun yams made by conventional and convergent channels are investigated at various suction air pressures. The results clearly indicate that the strength of yams made by the convergent channel is about 22% higher with no significant difference in elongation compared with yams made by the conventional channel at a suction air pressure of 2000 mmAq. Yarn twist at the various suction air pressures has no significant impact on yarns made by the two channels, meaning that the convergent channel provides the same twist efficiency as the conventional channel. We also find that yarns made by the convergent channel have a higher proportion of long effective fiber lengths and a lower proportion of short effective fiber lengths in which the total fiber extent is about 54.1 % compared to about 48.6% for conventional channel yams. We conclude that the superior strength of yarn made by the convergent channel is due to differences in its structure.