Research on spun yarn qualities in a modified ring-spinning system using airflow-twisting device

In this paper, a kind of airflow-twisting devices which can produce the twist by the high vortex airflow is employed for improving the twist propagation process of ring-spinning system. Firstly, three different kinds of yarns Ne20, Ne40, and Ne60 are spun in this modified ring-spinning system with five different airflow pressures and two different swirling directions, including anticlockwise and clockwise, and the qualities of spun yarns, including hairiness, strength, evenness, and number of snarling characterizing the yarn residual torque, are measured. Secondly, the images of spinning triangles are captured by using a high speed camera system OLYMPUS i-speed3, and the mechanism of the effects of vortex airflow on yarn qualities is discussed by analyzing the fiber tension distributions in the spinning triangle. It is shown that for the Z' twist spun yarn, the spinning triangle decreases with the increasing of clockwise airflow pressures, whereas the triangle becomes more and more symmetrical with the increasing of anticlockwise airflow pressures. Meanwhile, the comprehensive qualities of spun yarn are improved with the increasing of both directions of airflow pressures to a certain extent. However, the hairiness and strength of spun yarn will be mainly improved with clockwise airflow, whereas yarn residual torque mainly reduced with anticlockwise airflow.