Preventive Measures Of High-Speed Warping Broken Ends

September 10,2021

I Events

  When our company produces ST-ERL-808 products, the quality indicators such as evenness and strength have reached the user's requirements, but the warping breakage exceeds the standard in the preparation process. The user requires that the number of broken ends in warping for one million wires should be less than 0.6, but the number of broken ends in our company's warping is more than 1.8, which greatly exceeds the standard, which strictly affects the production efficiency of the subsequent process.

  The ST-ERL-808 product contains 30% long-staple cotton, the fine-staple cotton grade is 2.5, and the long-staple cotton is 137 Xinjiang cotton. The two components are produced separately and are mixed in the combing preparation process to maintain a certain mixing ratio. . The specific yarn indicators are as follows: even CV 12.3%, 4 kilometers of details, 20 kilometers of thick knots, 60 kilometers of neps, breaking strength 176cN, breaking elongation 3.6%, twist coefficient above 420 basic indicators Reached the 5% level of the Uster Communiqué.

  SUNTECH weaving machine uses TOYOTA high-speed warping machine in the warping process, the production speed reaches 800 m/min, the warping and threading distance is up to 15 m, and the nearest is about 3 m. A total of 600 bobbins are used on the warping rack. The position and the yarn guide movement are different. The warping tension is divided into 9 zones according to the front zone, the middle zone, the back zone, the upper row, the middle row and the lower row. After observation on the machine, the distribution of warping broken ends is mainly concentrated in the large package period. After the broken ends, the fibers at both ends of the yarn are distributed neatly, and after the broken ends, the yarn tails are embedded in the surface of the package, making it difficult to find the ends. The bobbins with broken ends are evenly distributed on the rack, eliminating the unsuitable warping tension factor, and the broken ends of small and medium-sized bobbins are obviously smaller than that of large bobbins.

  Take the following measures in response to the above problems:

1. Optimize the cotton cleaning process to increase the effective use length of long-staple cotton. The long-staple cotton card sliver has a basis weight of 17.5 g/5m, a carding cylinder speed of 360 r/min, a licker roller speed of 850 r/min, and a line speed ratio of about 2.2. It achieves moderate transfer, soft carding, and shortens the fiber in the cylinder and cover. Combing time between boards reduces fiber damage. The results showed that the total amount of cotton trash produced increased slightly, but the short fiber content decreased by 0.5%. The combing speed is controlled at 200 tongs/min, and the mixing process of the two raw cottons is adjusted from the sliver to the draw to ensure a uniform mixing ratio.

2. Reasonably choose the twist coefficient of the spun yarn. The original twist coefficient of spun yarn is 420, the breaking strength is 176 cN, and the twist coefficients of 410 and 400 are compared. When the twist coefficient is 400, the strength will be reduced by 15 cN, and the breaking elongation will be 4.5%. When the twist coefficient is 410, the strength will not decrease significantly, and the breaking elongation will be 4.3%, which is preferred. If the twist is too large, the twist angle of the fiber increases, which reduces the effective component force that the fiber bears in the axial direction of the yarn. At the same time, it increases the uneven distribution of fiber stress inside and outside the yarn, and aggravates the non-timeliness of fiber breakage. Maintaining a certain degree of yarn elasticity can reduce the probability of breakage of strong and weak loops in the subsequent process.

3. Lower the winding tension and reduce the loss of strength. The ESPERO-M type automatic winder used by our company produces CJ 9.7 tex products with a winding speed of 1100 m/min. The winding tension is originally set to 5 grids. Due to the longer winding stroke, the package density is much higher than that of ordinary winding. Large, it is the main reason why the yarn is embedded in the surface of the package after warping and broken ends. Adjust the winding tension to 2 grids and the winding speed to 900 m/min. The package is well formed and the winding density is appropriate. In view of the problem of warping broken ends mainly distributed in the period of large bobbin, the analysis believes that the air ring is small when the large bobbin is unwinding, and the friction between the unwinding yarn section and the surface of the bobbin is large. Therefore, it is decided to change the bobbin from 1.67 kg to 1.67 kg. Small packages of 1.19 kg (the original package of 25 kg yarn was packed with 15 packages, now it is loaded with 21 packages).

  As the  speeds up, some new problems have emerged in the production. As far as warping ends are concerned, the generating factors are more complicated and involve multiple links in the production process. Improving the basic strength of the yarn and reducing the strength and weakness of the original yarn are the fundamental solutions to the problem. In addition, from winding to warping, every processing link will reduce the elasticity and breaking elongation of the original yarn, reduce the winding tension, maintain the extensibility of the original yarn, and reduce accidental friction and stretching become particularly critical.

  By taking the above measures, SUNTECH has reduced the number of broken ends of one hundred thousand meters of warping from 1.8 to 0.6, which has been recognized by users. As weaving machine manufacturers, SUNTECH is worthy of your trust!