Research on the mechanism of the modified ring-spinning system using a dynamic twist-resistant device and its yarn quality

The spinning triangle is a critical area in the ring-spinning process; the geometry of the spinning triangle influences the distribution of the fiber tension, and affects the qualities of the spun yarn. In this paper, a kind of dynamic twist-resistant device that can affect the geometry of the spinning triangle is employed for improving the conventional ring-spinning system. The yarn twists between the front roller nip and dynamic twist-resistant device were captured in the spinning process using a high-speed camera. Comparing yarn twists of the two types of yarn, the modified yarns have a lower twist angle, indicating that the device can produce resistant torque. Particle Flow Code software was used to simulate the acts of the device on the yarn, and the results verified the existence of resistant torque. The resistant torque on the yarn affects the geometry of the spinning triangle and the distribution of fiber tension. In addition, 19.4 and 14.5 tex cotton yarns with three different twists, 700, 800 and 900 tpm, were produced by the modified and conventional ring spinning. The comparative study revealed that the modified yarns have a better performance in terms of yarn strength and hairiness, and show no significant difference in terms of the yarn evenness when compared with the conventional yarns at the same twist level. The mechanism of the effect of the dynamic twist-resistant device on yarn qualities is discussed by analyzing the distribution of fiber tension.