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Causes of defects after dyeing the yarn fabric

Update:13-05-2020
Summary:

After dyeing the polyester yarn woven into the fabric, […]

After dyeing the polyester yarn woven into the fabric, rung defects appear, which often cause great losses and are difficult to make up. The factors that produce the cloth rungs involve the entire process of textile dyeing. Among them, there are many reasons for the spinning process alone, involving the spinning raw materials, processes, environment, operation, machinery and other links and various processes, such as raw cotton maturity differences, weight Unevenness, uneven fiber blending, inadequate ageing, uneven twist, difference in hairiness, etc.

 

As far as cotton spinning is concerned, the influencing factors of the cloth rung are as follows:

 

1. Rails caused by improper cotton blending. The difference in micronaire value between cotton bale mixed label and batch is large, and the difference between cotton yellow and white is large. The micronaire value is low, the fiber is fine, and the maturity is poor. Due to the uneven cotton blending, the fabric surface is dyed horizontally after weaving. The key indicator micronaire value is strictly controlled within 0.5, and the yellowness + b value is controlled within 0.5 range. The difference between row and row micronaire value is ≤0.3, and the yellow and white bags are detected evenly on a bag-by-bag basis. The quantity of cotton supply is matched with cotton at one time.

 

2. Uneven cotton blending. Improve the operation rate of the cotton picking machine and the cotton box, as far as possible to grasp the cotton finely, diligently feed the thin feed, in order to reduce the weight of the cotton bundle, each process strictly implements fixed supply and cross-mixing.

 

3. Beams caused by many polyester yarn hairiness. The spun yarn travellers are replaced in strict accordance with the cycle. The selection of the ring and the travellers should be reasonable. The spun yarn spindles are in good condition and the self-winding yarn channel is smooth and free of burrs.

 

4. If the twist is too large, it will also cause knitting. Because twist affects the tightness of the structure of the polyester yarn, and then dyeing, it affects the combination of dye and cellulose. Strengthen the training of the car stoppers, reduce the occurrence of strong twisting of the joints, conduct regular and irregular inspections on the mechanical state of the twisted parts of the spun yarn, strengthen the inspection of the tour, and eliminate the slippage of the spindle belt on the edge of the spindle disk, loose spindle belt or inconsistent tension , Weak twisted yarn caused by lack of oil or damage to the spindle, burrs and joints of the spindle, and the pulley support of the spindle.

 

5. Unevenness and long section thickness cause rungs. Combing, drawing, and roving processes reduce the control of broken hairs. Each process must be stopped to ensure sensitivity and effectiveness, minimize the difference in roving size and polyester yarn tension, and choose fine yarn drafting reasonably. Equipment to improve the evenness of the yarn.

 

Nowadays, the market share of chemical fiber is increasing. Among them, the blended fabric that neutralizes the advantages of various raw materials has become the first choice of many customers. However, the spinnability and dyeing properties of different fibers are quite different. If the process is not paid attention to, it is easy to cause defects. About 70% of blended fabrics are caused by polyester yarn crossbar defects due to yarns, especially the raw material problems, especially because of raw material mixing problems. Therefore, it is necessary to pay special attention to the blending of yarn in the initial mixing of raw materials.

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