The Air Splicing Problem In The Production Of Coarse Yarn And Its Solution

With the continuous development of new and special yarns such as coarse yarn, strands, core spun yarn, Tencel yarn and so on, as the key components and core technology of the automatic winder, the problem of air splicer not suited to the quality requirements of new yarn splicing is becoming more and more obvious. The problem of twist has seriously affected the development and production of new yarn. This paper focuses on how to tap the function of the existing air splicer to solve the air splicing problem of coarse yarn.

The criteria for evaluating splicing quality are strength (strength retention rate) and appearance, but consistency and stability should not be ignored. Generally speaking, the standard of the strength retention rate in air splicing is generally more than 80% of the original yarn. However, the retention rate of the twist strength recommended by the overseas main engine to coarse yarns has dropped to 50% to 60% of the original yarn, indicating that it is very difficult for the coarse line to reach 80% strength. So what is the real problem of affecting the twist strength of coarse yarns? The stability is mainly due to the strength retention rate of some joints can reach 80% of the original yarn, but most of them are below 80%. However, as long as there is more than 80% of the yarn strength, it is possible to dig and solve problems. The key is to solve the problem of stability.

There are many factors that affect the stability in air splicing. Compared with ordinary yarns, coarse yarn has more problems to be noticed in twisting, and twisting has higher requirements for equipment selection and process setting. What are the main problems affecting the twist stability of coarse yarns? After excluding other factors, we should proceed from 2 questions: first, to reverse the twisting, and the two is to twist.

Back twisting

The untwist of coarse yarns is more difficult than that of medium yarns. It is necessary to ensure that the twisting effect of the 2 yarns is sufficient in the technological setting, and the following 3 factors affect the twisting effect.

1) scissors cutting time sequence and consistency.

2) ensure that the yarn enters the twist tube immediately after being cut.

3) for the upper and lower two twist tubes, different retwist settings are required.

Shear timing and consistency of scissors

This is a hardware problem, which involves the quality of the scissors and the stability of the scissors manipulating mechanism. These problems are relatively simple, so long as we pay attention to and repair and adjust them from the organization, we can solve them. However, there are still some problems that will seriously affect the stability of splicing strength, such as:

1) can scissors ensure that yarn can be cut every time?

2) does yarn slip on scissors?

3) can the upper and lower scissors ensure that the yarn is cut off at the same time?

If these problems can not be solved, the twisting effect will be affected by the twisting effect, which shows the slippage and strength of the twist joint is not high; if these problems sometimes appear, then the stability of the twist joint strength will be affected.

Ensure that the yarn should enter the twist tube immediately after being cut.

Coarse yarn is different from medium yarn and fine count yarn. On the one hand, because of the large flexibility of coarse yarn, it is easy to escape from the negative pressure suction range of the nozzle after cutting, and it can not be sucked into the twisting tube in time. On the other hand, because the diameter of the untwisted pipe of the existing air twister is smaller than that of coarse yarn, the coarse yarn can easily produce the phenomenon of not being sucked at the end of the twisting pipe. As long as one or two yarns are not able to be sucked into the twisting tube, the twisting effect will be affected. If two can not be inhaled, the problem of knot breaking is inevitable.

If the yarn is not allowed to be sucked into the twisting tube one hundred percent times after being cut, then the stability of the twist quality will be affected. In order to reduce the flexural resistance of coarse yarns, textile enterprises can choose the right rewinding pipe in the existing air splicer, choose the packing core yarn mode, adjust the temperature and humidity of the workshop to the suitable condition on the process selection.

Because when the coarse yarns are twisted, the diameter of the rewinding pipe is too thick or too thin, which will affect the twisting. The special twist tube can be used to solve this problem.

For the upper and lower two twist tubes, different twist setting settings are required.

The problem of splicing is sometimes considered from the overall condition of the equipment, such as the factors other than the Air Twister and the cyclonic factors such as the size of the splice and the size of the suction nozzle. It will also cause the twist of the original yarn to change. This situation is widespread. Originally, because of the poor quality of the ordinary yarn for the quality of the twisting, many of the winding technicians did not pay attention to these factors. The solution to these problems is to solve the problem by designing a new type of Air Twister, or by adjusting the existing air twister to make the upper and lower two twist tubes have different cyclones and air flow intensity, so that they can correspond to the different twists of the two yarns.

twisting

We should pay attention to the twisting equipment, the twisting pressure technology and the choice of twisting time.

Selection of twisting equipment

Under normal circumstances, coarse yarn splicing must have special splicing blocks for producing coarse yarn, but attention should be paid to the quality of the twisted piece itself, because it is already at the edge of the twist range, and the adaptability and tolerance of yarn splicing equipment to yarn should be considered, which will affect the stability of the splicing effect. Therefore, when the existing splicing equipment is used to splice the coarse thread, the splicing block should be optimized.

Selection of twisting pressure technology

Twisting pressure is critical to ensure the quality of coarse yarn. Generally, a higher air pressure (7.5 kg to 8.5 kg) should be selected. Therefore, it is better to use a booster pump to raise the pressure on the winder when producing coarse yarns. And must be the actual outlet pressure of the splice block, to ensure that the corresponding electromagnetic valve is always in good condition.

There is a problem with the increase of twisting pressure. It is because too high air pressure will easily damage the pressure capacity of some splicing equipment, such as the best choice of high voltage twisting equipment.

Selection of twisting time

The choice of twisting time and form of the current air splicer is basically only one way - single time, but for coarse yarn at high air pressure, it is not the longer the better, the right twist time should be chosen. The twisting time at high air pressure is long, and it is easy to cause the original yarn at both ends of twist to be damaged due to excessive twisting. It is shown that the ends of the ends are twisted and broken. Sometimes, these ends are not the problem of twisting, but are broken on the sides of the twisted joints due to the damage of the original yarn.

By optimizing the existing splicing equipment, we can find that the twisting quality of twisting is improved. The adjustment idea of the existing air splicer is also suitable for raising the splicing quality of ply yarn, Tencel and core spun yarn.