The yarn speed should be based on the quality of the yarn, the better the quality of the tube yarn to make the worse the degree of deterioration of the yarn, and vice versa will increase the degree of deterioration; at the same time the yarn speed and spool unwind tension is closely related to low speed When the tension higher speed slightly smaller. In the entire unwinding process, large and medium yarn tension is relatively small, less ring, the yarn speed can be slightly higher, but when unwound to the small yarn parts, unwinding tension doubled, easy to produce loop, limiting the winding Speed up. Therefore, in the large, medium yarn should increase the speed, should be properly decelerated yarn, so that the actual speed of the yarn increased. As a general rule of thumb, when spinning a medium variety, the percentage change in initial speed of the VSS variable speed system can be selected as + 30%, the final speed percentage is -60%, and the percentage of change is 70%. Different number of yarn winding speed and tension in Table 1.
Table 1.Different numbers of yarn winding speed and tension
Tension disc pressure/Pa
As can be seen from Table 1, when spinning different numbers of varieties, the speed of the vehicle and the tension of the vehicle vary with the number of signs. The lower the number, the lower the vehicle speed and the smaller the tension. This is because the yarn number of the yarn itself is smaller than the number of the yarn. If high-speed unwinding is easy to produce long details of yarn faults, it will worsen the quality of the yarn and make the yarn dryness CV value, hairiness, strength and other indicators Have different degrees of deterioration. Serious accidents will be broken, resulting in increased yarn, affecting production efficiency. The choice of speed also takes into account other factors, such as the supply problems before and after the more important indicators of the deterioration of the yarn. Under normal circumstances, the yarn into the CV value of deterioration to maintain the level of less than 0.5%, 30% of the yarn -30% details does not exceed 200 / km, the value decreases with the yarn number has increased.