Abstract: This paper reviews the spinning principle of low torque ring spinning technology by studying the modified spinning triangle and yarn twist and tension in the modified spinning zone. Furthermore, the 3D fiber configuration in low torque ring yarns and conventional ring yarns was analyzed using the tracer fiber technique. The results revealed the unique features of fiber helixes in low torque ring yarn, such as deformed non-concentric helix and local reversion phenomena. Those features experimentally offer useful explanations for the improved properties of low twist ring yarns and resultant fabrics. A systematical comparison was then made between low torque ring spun yarns and conventional yarns and their resultant fabrics, which show that low torque ring yarns have high yarn strength at low twists, low residual torque and less hairiness. The resultant knitted fabrics produced by low torque ring yarns have soft handle feeling and low spirality angles after several washing cycles, while the resultant woven fabrics possess better tearing strength, tensile strength and abrasion resistance. In addition, the 5th low torque ring spinning technology shows great improvement on the properties of the finer cotton yarn.

Key words: conventional ring spinning, low torque ring yarn, false twist, spinning teiangle, yarn structure