The importance of air splicer in self winding process
In the winding process, it is necessary to make the yarn into large bobbins which are conducive to the continuous production in the following process. At the same time, some defects on the yarn should be removed. Whether the tube yarn is rolled into a large package or the defects are removed, the two sections of yarn need to be knotted. There are a considerable number of joints in each bobbin. Take Murata 21C automatic winder as an example, each machine every day If the yarn length is 5000 meters and the winding speed is 1200 meters / minute, each winder has 60 spindles. The number of twists is 24 hours × 60 minutes × 1200 meters / min × 60 chips × 5000 meters. There are 20736 twists, which does not include the joints produced by cutting defects. Therefore, the quality of such a large number of twists has a great impact on the subsequent process According to the relevant literature reports, the economic losses caused by the breakage of a single yarn in winding and other subsequent processes are roughly estimated. It is concluded that the end breakage loss of warping is about 700 times of that of winding, that of sizing is about 2000 times of that of winding, and that of weaving is about 490 times of that of winding It is necessary to reduce the economic loss caused by yarn breakage by process efficiency. Here, I quote the words of Mr. Pan Zhongming, President of Shanghai Nengyi Electromechanical Technology Co., Ltd., an expert in air twisting, "the selection of winder is the selection of splicer".
Some factors affecting splicing quality and improving methods
The splicing process of air splicer is composed of two processes of untwisting and twisting. Under the normal conditions of untwisting tube, twisting cavity and length adjusting rod, the ideal untwisting and twisting result is a joint with uniform structure, good appearance and considerable strength. The retention rate of joint strength is generally more than 85%. The apparent diameter of the joint is 1.2-1.4 times of the original yarn diameter, and the length is 2.5 -75px, if it is lower than this standard or there are various conditions, then we should start from these two processes and eliminate them one by one.
Excluding external reasons (such as yarn quality, workshop temperature and humidity, mechanical influence, etc.), this paper only from the perspective of empty twist, expounds some factors affecting splicing quality and improvement methods.
2.1 analysis of the causes of high twisting error rate
The main causes of splicing errors are as follows:
(1) P1 and P2 quick connectors are not plugged in properly.
(2) Air splicer air volume adjustment is improper or splicing solenoid valve failure. The sound of untwisting and twisting is different. For the phenomenon of untwisting without twisting and twisting without twisting, the air volume regulating valve and solenoid valve of Air Twister should be checked. After cleaning or replacing the solenoid valve, the problem can be solved if the air volume reaches the standard.
(3) The main reason is that the untwist tube is far behind the normal position. Therefore, the untwist tube should be adjusted outwards to increase the air intake. The adjustment should be carried out in the unit of 0.1 mm. When the untwisting is not enough, it can be solved by rotating the untwist tube. The greater the twist is, the greater the rotation is.
(4) The splicing length is too short, and LN changes from ln8 to ln1 (adjusted according to varieties).
(5) The press in amount of the yarn holder should be 2-3mm. The opening width of the yarn holder corresponds to the width of the separator of the splicing bottom plate (front panel) (the gap is about 0.5mm). The adjustment of the press in amount is carried out with the adjusting screw of the yarn pressing rod.
2.2 cause analysis of slippage of twist joint
There are four main reasons for the slippage of twist joint
(1) If the twisting pressure is too low, properly increase the twisting pressure. Adjust the P2 pressure reducing valve according to the yarn type and yarn count, and the regulating amount is 0.2-0.65mpa. The insufficient holding force means that the twisting is not tight, which is related to the strength of the air whirl. The strength of the air whirl is related to the twist control itself, as well as the strength and speed of the twisting air swirl. The working effect of the twisting cavity is generally fixed, and there is no adjustable part in itself. Its work completely depends on the size of twisting air pressure and the length of acting time. If this kind of situation is found, it is necessary to check whether the twisting cavity is cracked, whether the rubber of the cavity cover has grooves, whether the cavity cover is closely matched with the bracket, whether the screws are tightened, and whether the untwisting pipe is damaged or not can be solved by timely replacement or adjustment.
(2) If the twist joint is too long, reasonably adjust the length of twist joint, and turn ln from ln1 to ln8 (according to the variety).
(3) If there is insufficient untwisting, refer to point 3 of splicing error.
2.3 the twist is thin and the strength is low
There are three reasons for this phenomenon
(1) If the twisting pressure is too high, the twisting pressure should be reduced and P2 pressure should be adjusted.
(2) If the splicing length is too short, adjust ln8 to the appropriate length.
(3) Excessive untwisting is characterized by too long untwisting length, thin and disordered head, and small white spots at the joint. This is because the untwisted pipe position is far ahead of the normal position, and the untwisted joint is too long, and the end fibers are not fluffy or the front ends of the fibers are intertwined with each other, resulting in neps at both ends of the joint or details at the joint. In this case, there is a certain strength, but the strength difference is relatively large If it is large, the untwist tube should be adjusted inward to reduce the air intake. The adjustment should also be carried out in the unit of 0.1 mm. Drag the tail at both ends of the spliced joint, adjust the position of LN, and move the LN forward. At the same time, test the twist strength to determine the best position.
2.4 one side of splice is thick and has tail
There are three reasons for this phenomenon
(1) If the twisting scissors are not good, the splicer should be well maintained, and the flying flowers at the scissors should be cleaned or the scissors should be replaced.
(2) If the upper or lower yarn clamping is not good, the guide bar may be attached with flying flowers or the guide bar is deformed and marked, which may cause the clamping not in place. The problem can be solved by removing the flying flowers and replacing the yarn guide rod.
(3) The position of one side untwisted tube is poor, which can be solved by a little adjustment.
Through a series of targeted adjustment and maintenance, the quality of yarn splicing has been significantly improved, and the splicing error rate has been reduced by less than 10% from the original 22.4%.
conclusion
In modern spinning, splicer is a unique part of jointless yarn, and its joint quality has a great impact on the subsequent process. To ensure good quality, it is very important to adjust the process parameters such as untwisting, twisting and joint length. Air splicer is the core component of automatic winding to ensure the quality. The use of splicer improves the internal and external quality of the yarn, and also improves the production efficiency of the subsequent process. In actual production, for different raw materials, yarn number, we should adjust according to the actual situation to ensure the splicing process parameters, so as to ensure the quality of the joint and achieve stable, strong, efficient and high-quality Purpose.
