The characteristics of rotor (rotor spinning) yarn and its main differences from ring spinning are as follows:

The strength

  • The strength of rotor spun yarn is lower than that of ring spun yarn because there are many bending, looping, folding and winding fibers in rotor spun yarn, and the transfer degree of inner and outer fibers is poor. When the yarn is subjected to external force, the difference of fiber fracture is more serious, and because the contact length between fiber and fiber is short, the fiber is easy to slip under external force, so the strength of rotor spun yarn is lower than that of ring spun yarn. When spinning cotton; The strength of rotor spun yarn is about 10 ~ 20% lower than that of ring spun yarn; When spinning chemical fiber, it is about 20 ~ 30% lower.
Ring frame spinning

Ring frame spinning

Evenness of sliver

  • Evenness rotor spinning does not need roller drafting, so there is no mechanical wave and drafting wave of ring spinning evenness. However, if hard impurities are embedded in the coagulation tank, periodic unevenness equal to the circumference of the spinning cup will also occur. In addition, if the combing roller is wound, the fiber separation is poor or the fiber moves irregularly, it will also cause uneven evenness of coarse and fine sections. However, generally, the combing effect of the combing roller is strong, the fiber separation is good, and there are few defects such as fiber seed chips and cotton bundles, which is conducive to uniform evenness. In addition, rotor spinning has the effect of blending uniformity in the coagulation process. Therefore, the evenness of rotor spun yarn is more uniform than that of ring spun yarn. In the spinning of medium special rotor spun yarn, the average ubbelohdegree unevenness is 11 ~ 12%, some are less than 10%, while that of the same special ring spun yarn is 12 ~ 13%.
  • In addition, when raw cotton passes through the front spinning machine, it has a strong opening and clearing effect, and there is more impurity, especially through the spinner with impurity removal device. At the same time, due to the separation of fibers and impurities in the spinning cup, a small part of dust and neps are left in the spinning cup, so the rotor yarn is relatively clean and the yarn defects are small and few. The number of yarn defects of rotor spun yarn is only 1 / 4 ~ 1 / 3 of that of ring spun yarn.
ring spinning

ring spinning

Wear resistance

  • Tthe wear resistance of yarn is not only related to the uniformity of yarn itself, but also closely related to yarn structure. Because the ring spinning fiber is a regular helix, when repeated friction, the helix fiber gradually becomes an axial fiber, and the whole yarn will lose twist, disintegrate and break quickly. The outer layer of the rotor yarn is wrapped with irregular winding fibers, so the rotor yarn is not easy to disassemble, so the wear resistance is good. Generally, the wear resistance of rotor spun yarn is 10 ~ 15% higher than that of ring spun yarn. As for the wear resistance of rotor spun yarn twist, due to its rough surface and good holding between yarn and yarn, rotor spun yarn twist has better wear resistance than ring spun yarn twist.

Elastic

  • Spinning tension and twist are the main factors affecting yarn elasticity. In general, the spinning tension is large and the yarn elasticity is poor; Large twist and good yarn elasticity. Because the spinning tension is large, the fiber is easy to exceed the elastic deformation range, and it is difficult for the fiber in the yarn to slide after spinning, so the elasticity is poor. The yarn has large twist and large fiber inclination angle. When stretched, it shows spring like elongation, so it has good elasticity. Rotor spun yarn belongs to low tension spinning and has more twist than ring spun yarn, so the elasticity of rotor spun yarn is better than ring spun yarn.

The twist

  • General the twist of rotor spun yarn is about 20% more than that of ring spun yarn, which will cause difficulties in some post-processing. For example, the processing of some pile fabrics is more difficult. At the same time, the twist is large and the hand feel of the yarn is hard, which affects the hand feel of the fabric. Therefore, it is necessary to study the measures to reduce the twist of rotor yarn on the premise of ensuring a certain single yarn strength and yarn breakage.
Open end rotor spinning

Open end rotor spinning

Fluffy

  • The yarn Fluffy is expressed by specific volume (C ㎡ / g). Due to the poor straightness and irregular arrangement of the fibers in the rotor spun yarn, the tension of the yarn is small in the twisting process, and the outer layer is wrapped with winding fibers, so the structure of the rotor spun yarn is fluffy. Generally, the specific volume of rotor spun yarn is about 10 ~ 15% higher than that of ring spun yarn.

Dyeing and sizing

  • Dyeing and sizing absorption because the structure of rotor spun yarn is fluffy, it has strong water absorption, so the dyeing and sizing absorption of rotor spun yarn are better, the dyes can be used less by 15 ~ 20%, and the sizing concentration can be reduced by 10 ~ 20%.