What impact does warp yarn tension on product quality have?

The warp thread tension on the machine during weaving not only directly affects the production operation, but also seriously affects the quality of the product. The rib rails of some products, a few pry rails, and the unilateral rails formed by people pressing the warp surface are all due to the warp yarn tension. Caused by improper machine tension. Specifically, the impact of warp yarn machine tension on product quality is generally in the following aspects:
1Influence on breakage rate
From the time when the warp wires come out of the warp beam to being woven into fabric, they have to go through thousands of times of stretching and friction by guide rollers, healds, and steel reeds. The tension on the wires increases, which easily causes fatigue and breaks at the weak links of the warp wires. Therefore, excessive upper machine tension is the main cause of warp wire breakage. Someone once conducted an experiment on a certain fabric and adjusted the warp yarn tension, sheer flatness, warp position and other related factors to reduce the warp breakage rate from 0.839 yarns/machine·hour to 0.175 yarns/machine·hour. . Can it be considered that the smaller the tension on the machine, the lower the breakage rate? After analysis, the beat-up force on the general fabric is not 90°, so the beat-up force can be decomposed into the force F along the fabric direction and the force f perpendicular to the fabric direction. When the beat-up force remains unchanged, if the warp tension decreases, Then the beat-up force F in the direction of the silk surface will inevitably decrease, so the fabric forming area and the beat-up area will increase. In this way, the friction between the warp threads between the reed and the healds is increased, and the warp threads are “stuffed” in front of the reed, which leads to an increase in breakage. Therefore, the warp thread tension on the machine that is too small is harmful to the warp threads. Weaving is also disadvantageous.
2Influence on fabric shrinkage
If the warp tension is high and the warp and weft are interlaced, the warp compresses the weft, causing the weft to buckle and increase the internal stress of the weft. When the fabric is rolled into the take-up roller, especially after it is removed from the machine, the tension of the warp threads disappears, and the weft threads will exert greater counter-pressure on the warp threads due to the “resistance” of the internal stress, resulting in an increase in warp shrinkage. , the impact of reduced weft shrinkage on fabric feel and appearance
The tension on the warp thread has a great influence on the feel and appearance of the fabric. If the tension on the warp thread is properly controlled, the silk surface of the fabric will be flat, the texture will be clear, and the hand feel will be good. If the warp thread tension is too high, it will cause If it is stretched too much, the silk surface will not be plump enough, and the warp thread tension on the machine is too high, and the fabric is likely to have a “thin gap”.
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