Summarize:
Technical measures to improve air-jet loom efficiency and product quality. The influence of high-quality yarn on loom efficiency and gray fabric quality is briefly analyzed. Combined with production practice, the targeted technical measures that should be taken in the warping, sizing and weaving processes are summarized in detail. The close relationship between yarn quality, warping and sizing quality, loom technology, equipment operation and fabric quality was analyzed. It is believed that selecting high-quality yarn, ensuring the quality of warping and sizing yarns, and strengthening the technical management of the weaving process will help improve the efficiency of the loom and the quality of the fabric surface.
With the continuous advancement of technology, air-jet looms are becoming more and more versatile and faster. The maximum operating speed of the JAT⁃810 air-jet loom can reach 1,000 r/min, and the speed of 750 r/min~850 r/min can enable continuous normal production. Our company has more than 200 JAT⁃810⁃230 air-jet looms. Since it was put into production in 2013, it has continuously explored and innovated in technology, and has successively developed high-quality pure cotton and blended fine and high-density series fabrics, filaments and Staple fiber yarn series interwoven fabrics, core-spun yarn series elastic fabrics, etc. This article summarizes our production technology management experience from the following five aspects for reference by peers.
1 Select high quality yarns
Since the air-jet loom is operating at high speed, only high-quality yarn can adapt to the weft insertion line speed of 1 600 m/min~1 800 m/min. It is necessary to choose outsourced yarn produced by enterprises with high management level, advanced equipment and stable product quality. The main quality indicators of purchased yarn must be tested and analyzed before use. Only when the indicators meet the requirements of the production variety can it be officially put into production.
There are different emphasis requirements on the quality of warp and weft yarns. In order to reduce warp breakage, its strength and strength unevenness are the focus, and details, thick spots, weak twists and large knots must also be carefully checked. The weft yarn focuses on controlling the number of hairs to ensure a smooth surface and reduce weft insertion breakage.
Fine high-density anti-down fabrics and other varieties mostly use 7.3 tex ~ 9.7 tex yarn. In order to ensure the strength of the single yarn, it is necessary to use combed, compact spinning or siro spinning yarn. After the combing process, most of the short velvet is removed. Not only the yarn strength is significantly improved, the hairiness is reduced, but the neps and yarn defects of the yarn are also significantly reduced. It is more suitable for making yarn for high-end fabrics. Multiple tests have also shown that the strength of siro spinning or condensed siro spinning is more than 10% higher than that of conventional yarn, and the 3 mm hairiness is about 70% lower. In addition, adding a certain proportion of long-staple cotton to the yarn can also improve yarn quality and significantly improve loom efficiency. Taking the JC 7.3× (JC 9.8+C 19.0) 535×484 199 plain weave variety as an example, the warp yarn uses 70% long-staple cotton + 30% fine-staple cotton and all uses fine-staple cotton. The single yarn breaking strength increases from 134 cN to 170 cN, the weft breakage of 100,000 meters of weft yarn is reduced from 9.5 to 1.5, the warp breakage of 100,000 meters of weft is reduced from 5.6 to 1.2, and the loom efficiency is increased from 72.4% to 95%. It can be seen that the improvement effect is very obvious.
When selecting elastic core-spun yarn to produce elastic fabrics, the core yarn and the outer covering fiber should be selected to ensure a good match between the two, so as to avoid bare yarns due to poor covering, resulting in fabric defects. In order to ensure the coating effect, 44.4 dtex spandex yarn should be selected when producing elastic core-spun yarns below 18.3 tex, and 77.7 dtex spandex yarn should be selected when producing elastic core-spun yarns between 18.3 tex and 36.0 tex. In addition, it is necessary to ensure that the elastic core-spun yarn has moderate elasticity and the elastic elongation should not be too large. Different elastic fabrics have different elasticity and elastic elongation requirements, and the core yarn should be selected according to the different elastic requirements of the fabric.
For outsourced yarn, in addition to quality indicators such as yarn strength, hairiness, yarn defects, and various unevenness, attention must also be paid to the appearance quality and splicing quality of the package yarn. The appearance of the package yarn should be clear and without overlap. Poor splicing quality of package yarns will also increase warp yarn breakage during warping, affecting loom efficiency and fabric surface quality. We require that the splicing length of the package yarn should be between 18 mm and 25 mm, the thickness of the splicing point should not exceed 1.2 times the diameter of the original yarn, the knot strength should reach more than 85% of the original yarn strength, and the pass rate of splicing strength should be 95%. above.
2 Warping process
2.1 Optimize equipment and optimize processes
Our company has 2 imported warping machines and 2 domestic warping machines. The imported Karl Mayer warping machine has advanced equipment, and the tension of the creel is evenly distributed, which can adapt to high-speed and smooth operation, and has excellent braking performance. It is mostly used to produce fine, high-density and high-end varieties. The domestic ASGA228 warping machine is mostly used to process medium and fine varieties with a small total number of warps.
Warping machine loading process. First of all, the warping traction and winding speed must be reasonably designed. It should be controlled according to the yarn material used (such as pure cotton yarn, blended yarn, core-spun yarn, chemical fiber yarn), yarn number, and the total number of warps in the entire shaft. Within 85% of the design speed of the warping machine. Karl Mayer’s warping machine is designed to have a maximum speed of 1,000 m/min, but we control it at around 850 m/min during actual production. The designed maximum speed of domestic warping machines is 800 m/min, but in actual use it is controlled between 600 m/min and 650 m/min. The higher the operating speed of the warping machine, the more intense the friction between the yarn and each yarn guide, which can easily lead to increased yarn elongation and tension changes, resulting in a significant increase in yarn hairiness. In addition, the higher the operating speed of the warping machine, the longer the braking distance, which makes it easy for the yarn end to be rolled into the shaft. Therefore, a reasonable design of the warping speed can ensure that the end-break automatic stop device and the braking device are flexible and effective, and the braking distance is It should not exceed 4 m.
Package yarn arrangement and package changing method. The position of the package yarn on the creel is different, and the yarn tension�Standards and related management systems, the temperature in winter is controlled at 20 ℃ ~ 24 ℃, the relative humidity is 66% ~ 76%, and the temperature in summer does not exceed 33 ℃, and the relative humidity is 66% ~ 76%. In order to strictly control the temperature and humidity within the standard range, we specially deploy shift adjustment personnel and equipment maintenance personnel to ensure that the air conditioning equipment is in good operating condition. In addition, according to the condition maintenance method, refueling is performed at the specified time and key components (such as weft feeder, reed, main and auxiliary nozzles, etc.) are regularly maintained and repaired, inspections are conducted on a shift basis, and abnormalities are repaired and replaced in a timely manner to ensure that the equipment is always In good high-speed operating condition and extend its service life.
6 Conclusion
How to continuously improve production efficiency and product quality under the condition of high-speed operation of air-jet looms is a technical problem that textile enterprises must face. By optimizing yarn raw materials, improving the quality of warping and sizing, and doing a good job in technology, equipment, and operation in the weaving process, our company has not only cultivated a team of employees who understand technology, are willing to endure hardships, and can work hard from production practice, but also It also creates better economic benefits for the enterprise. The series of fabrics produced have low breakage rates in the warp and weft directions, fewer defects in the gray fabrics produced, the loom efficiency reaches about 95%, and the first-class product rate reaches more than 93%. The annual output of various types of high-end fabrics is more than 25 million meters. The sales output value is nearly 300 million yuan.
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