Research on shape of spinning triangles in the ring spinning system

Abstract

Ring spinning is the most widely used yarn spinning method at present. Spinning triangle is a critical area in the ring spinning process of staple yarn, in which the geometry influences the distribution of fiber and fiber mechanical properties in the spinning triangle directly, and determines the qualities of spun yarn. Therefore, some new modified ring spinning methods have been appeared gradually by changing the spinning triangle actively. In this paper, the qualities of yarn spun by common ring spinning and two kinds of modified ring spinning were studied by analyzing the shapes of spinning triangle. First, 18.2tex cotton yarns were spun on FA507B ring spinning frame with three different spindle speeds and leading distances of top roller, and corresponding spinning triangles were captured using a high-speed camera system OLYMPUS i-speed3 and one kind of transparent front top roller. Then, the qualities of yarn produced by modified FA507B ring spinning system with four-line rollers compact spinning device and a kind of airflow twisting device were analyzed, respectively. 29.2tex, 14.6tex, 9.7tex yarns, and 18.2tex yarns with three negative pressures 1800, 2200, and 2600 Pa were spun, respectively, and corresponding spinning triangles were captured and analyzed comparatively. It is shown that using compact spinning device, the spinning triangle is reduced greatly, and with the increase in negative pressure, the spinning triangle is reduced gradually. Furthermore, 18.2tex yarns were spun on FA507B ring spinning frame and FA507B ring spinning system modified by a kind of airflow twisting device with airflow pressure 0.1Mpa and 0.05Mpa and two different swirling directions including anticlockwise and clockwise, and corresponding spinning triangles were captured and analyzed. It is shown that for the Z (S) twisting spun yarn, under the effects of the clockwise (anticlockwise) airflow, the spinning triangle can be reduced and benefit for reducing yarn hairiness, while under the effects of the anticlockwise (clockwise) airflow, spinning triangle is more symmetric and benefit for reducing the yarn torque possibly.