The twisting and winding of the spun yarn are carried out simultaneously. Because the traveler is subject to friction and air resistance on the track, the speed of the traveler lags behind the spindle speed, and the speed difference between the two causes winding. The twisting and winding part is the most important part that causes end breakage in the spinning machine, so what are the control points?
Steel ring options
The diameter, hardness, and edge width of the steel ring should be selected correctly according to different varieties and yarn numbers (but first, the inherent quality of the steel ring must be ensured and trial spinning to determine).
Traveler weight options
Proper traveler weight controls spinning tension. Selection principle: when the small yarn has a large diameter, the balloon should not be too large, and when the large yarn has a small diameter, the balloon should not be too small (or after the distance between the yarn guide hook and the top of the bobbin is determined, the small yarn balloon should not touch The bobbin head is sufficient). In addition, if a new steel ring is put on the car, due to the large friction factor of the steel ring or traveler, the traveler should be selected with a lighter weight. As the use time of the steel ring increases or the steel ring declines, the friction factor gradually decreases, which will occur during production. If the balloon expands and yarn breaks increase, the situation should be aggravated. (If the count is fine, you should choose a lighter one. If the ring diameter is large and the spindle speed is high, choose a lighter one; if the tapered ring should be lighter by 1 to 2 numbers; the yarn strength is high, the bobbin is long, and the yarn guide hook is on the bobbin. If the distance between the top of the tube is large, the wire ring can be heavier; if the climate is dry and the humidity is low, the wire ring can be heavier.)
Reduce twisting
Reduce twisting and improve the dynamic strength of the yarn. It can be seen from the measurement results of dynamic strength that the dynamic strength is much lower than the bobbin strength. The reason is that during the twist transfer process, the friction resistance of the yarn guide hook on the yarn causes twisting and twist transfer hysteresis, which causes the spinning section to The twist gradually decreases. If the length of the spinning section is longer, the twist of the section will be smaller. When a sudden change in tension occurs, end breakage will easily occur.
Measures to reduce twisting
The yarn guide hook is in normal condition and cannot have grooves or burrs; increase the yarn guide angle (the yarn guide angle is determined by the design of the OEM and basically cannot be changed. This problem can be solved through compact spinning transformation, but it also brings steel wire The loop operation is unstable and easy to jump, but a small loop type yarn guide hook can be used).
At the same time, looking at the twist distribution of spinning yarn in a doffing yarn, the twist is less on small yarns, in the middle for medium yarns, and more twists on large yarns. Small yarns have a lot of twist when they are wound with a small diameter, and the twist is the smallest when a large diameter is wound, which is about 22% less than the average twist of the bobbin, resulting in a significant reduction in spinning strength, so this is one of the reasons why there are more ends breakage when a small yarn is wound with a large diameter. Therefore, in the spinning process, how to increase the dynamic twist of the yarn segment in the weak twist area, thereby improving the dynamic strength, is also of great significance in reducing and reducing end breakage.
① Reduce the length of the twistless triangle area. Because it has a great influence on the dynamic strength of spinning, many people have studied this aspect. However, for example, the yarn guide angle β and the roller seat inclination angle have been determined in the design of the spinning machine, as well as other reasons. Therefore, it is generally used in production. The front rubber roller is used to complete the front punch. However, if the forward stroke is too large, the length of the floating zone will be increased, affecting the quality and the effective pressure of the cradle. Therefore, the general forward stroke is 2 mm~3 mm; in addition, since the size of the negative pressure tube or small roller of the compact spinning transformation has been determined, the forward stroke is also determined.
② Increase the gripping force of the front top roller on the whiskers. It may have certain practical significance. But according to the existing “Lu S technology”, there is a bit of a conflict. In addition, excessively increasing the weighting arm pressure may sometimes be counterproductive, so this work should be carried out according to process requirements.
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