Nu-Torque™ Yarn

Developed by The Hong Kong Polytechnic University since 2002, Nu-Torque yarn technology allows the production of torque free singles ring yarns by a single step on a ring spinning machine.

Nu-Torque cotton yarns and fabrics have good soft handle and improved fabric surface appearance, higher yarn tenacity at lower twist levels, lower residual torque and lower hairiness, and yarn novel effects, in addition to low knitted fabric spirality after washing. In the finer cotton yarn sector, the technology can provide much thinner and lighter fabrics produced by the finer yarns whose linear densities are reduced by half. With unique wool like softness of fabric made from Nu-Torque cotton yarns, this technology will help cotton to be better applied and to compete with fibers like wool and other man-made fibers in the areas of shirts, polo shirts, pants and sweaters. However, the current technology is difficult to manufacture finer yarn counts, even at 30Ne.

This project is intended to further develop the technology for mass production of finer Nu-Torque cotton yarns for weaving and knitting. The target yarn counts are 30Ne and 40Ne.

Application

• A physical manufacturing method to produce torque balanced singles ring yarns in a single step.
• A false-twister and related components for the short staple yarn to produce low torque yarns in existing spinning mechanism.
• A control mechanism of yarn residual torque and a method to control yarn tension by adjusting the speed ratio through a mechanical device.
• Production of yarns at a range from 7Ne-100Ne (~6tex-85tex) with twist level 25 - 40% lower than traditional ring yarn.
• An electronic control system was developed under the 5th generation of the Nu Torque technology which enables the ring spinning frame to produce standardized and quality Nu Torque yarn.

Industry Benefit

• Yarn production cost: 24-40% increase in productivity because of lower twist level at the same yarn strength; 10% saving as no yarn plying is needed.
• Finishing: 15-20% saving on finishing treatment needed for the conventional cotton fabric.
• Knitting: 10% saving in knitting cost due to lower spirality and clear surface with symmetrical loops.
• Energy saving: saving around 337 units (kilowatt hours) of electricity per one ton of yarn produced.
• Environmental-friendly: no chemicals, no water and steam required for production.
• Quality: cashmere-like soft handle.

Technological Breakthrough

It is a major breakthrough in yarn manufacturing, which provides the means to produce singles ring yarn. The technology brings optimised processing parameters for spinning, weaving, knitting, dyeing and finishing as well as improvement to the overall throughput of a spinning factory by improving bottleneck operation in spinning process. It is estimated that the overall productivity of a spinning operation will be enhanced by 20-40% with lower production cost and better product quality.

Project Name (ITF)
Finer Nu-Torque Cotton Yarn Production
Project Number (ITF)
ITP/003/07TP