Solution to the problem of loosening yarn edge on air-jet loom

Solutions to the problem of loosening yarn edges on air-jet looms. 

The causes of loosening edge are analyzed, which include: side yarn healding method, setting of waste side yarn, shearing time, side bracing position, air jet pressure, tension of hem yarn, opening time, heald frame height, etc. 

Through the above measures, the problem of loosening edge was solved, weft stop was reduced, loom efficiency and first-class product rate were improved.

Reasons for loose edge in spinning

It is well known that air-jet loom spinning has the characteristics of high speed, high efficiency and high quality. 

However, if we want to give full play to its characteristics, we must have high quality raw yarn, high quality semi-finished products, reasonable process parameters, excellent equipment maintenance quality and operation technology level. 

Since the operation of this type of air-jet spinning loom, we have made sufficient preparations for the raw yarn and semi-finished products, basically ensuring the production conditions. 

However, after large-scale production, we found that the production efficiency is not ideal. Most spinning machines have loose edges. Weft stops are very serious. 

The frequency of 100,000 weft stops is about 10, and the efficiency of spinning looms is only about 80%. To this end, technical personnel to study and tackle key problems. 

Through analysis, the main factors affecting weft stop are: side yarn healding method, waste side yarn, shearing time, side brace position, jet pressure, tension of hem yarn, opening time, height of heald frame, process setting of drawing nozzle, etc.

Main technical measures

(1) To change the method of side yarn healding. Put the side yarn on the front harness as far as possible. For example, the method of side yarn healing is changed from 3434 to 1414, and the method of side yarn healing is changed from 6767 to 3636.

(2) Six to eight waste edge yarns must be ply yarns, the thickness of which is comparable to that of textured yarns.

(3) Adjusting shear time. Early shearing time is easy to cause loose edge, which can be adjusted from 20 to 26.

(4) Adjusting the position of side brace. Put the first ring on the edge to press down the edge of the cloth.

(5) Adjusting various jet pressure. The principle is: atmospheric injection pressure < shear pressure < main injection pressure < auxiliary injection pressure.

(6) Adjusting the tension of the hem yarn. In principle, the yarn is tightened to the left and loosened to the right, and 77 dtex filament is used for hemming yarn when the warp yarn is less than 29 tex.

(7) Adjusting the opening time. The opening time of the weft is 290 degrees when the arrival time of the weft is 230 degrees, and 310 degrees when the arrival time of the weft is 240 degrees.

(8) Height setting of heald frame. The heddle heddle height of plain weave fabric is 74 mm, 72 mm, 70 mm and 68 mm respectively; the heddle height of upper and lower twill weave fabric is 74 mm, 72 mm, 70 mm and 74 mm respectively; the heddle height of upper and lower twill weave fabric is 72 mm, 70 mm, 68 mm, 66 mm, 72 mm and 70 mm respectively; the heddle height of upper and lower twill weave fabric is divided into four parts. They are 68 mm, 66 mm, 64 mm, 62 mm, 60 mm and 64 mm, respectively.

(9) The location of the stretching nozzle should be appropriate. Use 4 squares and 3 degrees to let the weft blow straight naturally.

Conclusion

By taking measures such as changing the healding method, setting waste edge yarn, adjusting shearing time, edge bracing position, air jet pressure, tension of stranded yarn, opening time and heald frame height, the problem of loosening edge is effectively solved, weft stop is reduced, loom efficiency and first-class product rate of warehousing are improved, and the economic efficiency of our company is improved. Benefits provide technical assurance.