Thin yarn weak twist means that the twist is lower than the normal value, the strength of the yarn after the thin yarn is broken, the joint is difficult, and the short segment yarn is in a small twist state, commonly known as weak twist.

01Homogeneity:

Rough details produced by uneven drafting, in the twisting process, the twist is concentrated to the details, the twist at the thick section is small, the strength is low, or the details are too long, the formation of fragmented twist coefficient is low, the strength is low. The long details generated by roving cause form insufficient twist and low strength during yarn formation.

Whole ingot:

If a single spindle is faulty, the whole yarn is thicker than the normal yarn, and the yarn may be accompanied by a steel collar.

Whole set: process error occurs

From the actual production process, the greater impact is a local weak twist and the whole ingot weak twist. A weak twist is not connected to the top, the value of the turning worker's opinion is large, the whole single ingot weak twist, not because of the forming of the steel collar, not easy to be found out, is the key work to control the weak twist. The whole weak twist is not easy to occur, and it is easy to be found, and generally will not cause negative effects.

The harm of weak twisting yarn

02

Force drop

Produce yellow and white. The contrast is more obvious after absorbing color

Repeated breakage of fine yarn increases

Easy to produce abrasive yarn

Knitting and weaving machine breakage increase

Weak twisting tends to produce hairiness

Soft twist cotton ball

When the yarn with weak twist is used as the warp, because of the color absorption, it will produce the color warp with long direction

The main factor of irregular twist

03

1. When the roving machine does not use the false twister, the twist of the spinning section is far lower than the process design twist, so that the elongation of the roving spun out of normal is also larger (generally greater than 2%). This is mainly because the top of the ingot wing is the twist point, and the greater the friction effect of the top of the ingot wing, the stronger the twist phenomenon of the yarn strip.

2, the evenness of the fine yarn is poor, especially the production of thick knots and details has a greater impact on the twist unevenness of the yarn.

3. Uneven spindle speed is an important reason for uneven yarn twist. The uneven spindle speed is mainly caused by the roller of the spindle, the spindle condition and the slip rate difference between the spindle and the spindle. The main factors affecting the slip rate are the tension of the spindle, the quality of the inner and outer layers of the spindle, the difference between the taper of the spindle tip and the diameter of the spindle and the lubrication condition of the spindle.

4, the influence of the length of the ingot belt and the tension of the ingot belt on the ingot speed: the ingot belt tension is large, the slip rate between the ingot belt and the rolling disc is small, the slip rate between the ingot plate and the ingot belt is also small, the ingot speed is high, so the twist of the yarn is large. Otherwise, the yarn twist is small.

The influence of the strip length on the strip tension: the length of the strip is small, and the length of the strip is large. If the spinning machine and twisting machine on the same platform of the ingot belt length is inconsistent, that is, resulting in the same platform of the ingot belt tension difference, resulting in the same platform of the ingot speed uneven, it affects the yarn twist uneven. Ingot belt hitch head, twisted and damaged rough edge, ingot belt flying adhesion too much, ingot with oil and so on caused by spindle and ingot belt disk rotation is not flexible, beating, etc., will have a certain degree of influence on the twist irregularity of yarn.

5, spindle and bobbin supporting poor contact, bobbin top inner hole wear or not round, too light weight, spindle bending and spindle running instability, etc., will lead to yarn in the running of the tube or "invisible skip", resulting in yarn twist irregularity rebound.

6, because the sense of responsibility is not strong and the workshop laboratory management is not strict, the twist change number of teeth is wrong, resulting in a large number of strong twister yarn, that is, wrong twist yarn.