1) Selection of steel collar: The diameter, hardness, a […]
1) Selection of steel collar:
The diameter, hardness, and edge width of the ring should be correctly selected according to different varieties and yarn counts (but first of all, the internal quality of the ring must be ensured, and the trial spinning should be carried out to determine.)
2) Selection of traveler weight:
The right traveler weight can control the spinning tension. Selection principle: The balloon should not be too large when the diameter of the small yarn is large, and the balloon should not be too small when the diameter of the large yarn is 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 tube head is enough). In addition, if the new ring is on the car, because the friction coefficient of the ring or the traveler is relatively large, the traveler should be selected lightly. As the use time of the ring increases or the ring declines, the friction coefficient gradually decreases. When the balloon is enlarged and the yarn breakage increases, it should be aggravated at this time. (If the count is small, choose lighter, if the ring diameter is large, the spindle speed should be lighter; if the cone surface ring should be reduced by 1-2; the yarn strength is high, the bobbin is long, and the guide hooks to the bobbin If the distance between the top ends is large, the traveler can be heavier; if the climate is dry and the humidity is low, the traveler can be heavier.)
3) Reduce twisting and improve yarn dynamic strength
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 the frictional resistance of the guide hook to the yarn causes the twist sink and the hysteresis of the twist transmission during the twist transmission process, which makes the spinning section The twist is gradually reduced. If the length of the spinning section is longer, the twist of the section is smaller. When a sudden change of tension occurs, it is easy to break ends.
4) Measures to reduce twisting:
The yarn guide hook is in a normal state and cannot be grooved with burrs, etc.; increase the yarn guide angle (the yarn guide angle is determined by the design of the OEM and cannot be changed. The compact spinning modification can solve this problem, but it also brings steel wire Loop operation is unstable and easy to jump, but small loop type yarn guide can be used.)
At the same time, looking at the spinning twist distribution of a doff, the small yarn has less twist, the middle yarn is in the middle, and the large yarn has more twist. When the small yarn is wound with a small diameter, the twist is more, and the twist is the smallest when the diameter is large, which is about 22% less than the average twist of the bobbin, which causes the spinning strength to be significantly reduced. Therefore, this is also one of the reasons for the more broken ends when the small yarn has a large diameter. Therefore, in the spinning process, how to increase the dynamic twist of the yarn section in the weak twist zone, so as to improve the dynamic strength, is also of great significance for reducing and reducing the breakage.
①Reduce the length of the untwisted triangle. Because it has a great influence on spinning dynamics, many people have studied in this area, but for example, the yarn guide angle β and the inclination angle of the roller seat have been determined in the design of the spinning frame, and other reasons, so it is generally used in production. The front top roller is punched forward to complete. However, if the forward thrust is too large, the length of the floating zone will increase, which will affect the quality and the effective pressure of the cradle pressurization, which will affect the quality. Therefore, the general front impulse is 2-3 mm; in addition, because the size of the negative pressure tube or small roller has been fixed for compact spinning transformation, the front impulse is also fixed.
②Increase the holding power of the front top roller to the beard. It may have certain practical significance. This work should be carried out according to the process requirements.