Abstract:
Discuss the characteristics and application effects of mechanical rolling and twisting technology. The supporting points, working principle and working process of mechanical twisting and splicing technology are analyzed. Pass the test. The optimal configuration of the three splicing parameters of untwisting, drafting and twisting of JC9.7tex gathered yarn was selected. The key points of splicing parameter adjustment, various requirements for splicing quality and equipment management are explained. It is believed that mechanical twisting and twisting technology has the advantages of excellent appearance and high joint strength, and has a wide adaptability range, and is more suitable for splicing higher-grade concentrated yarns. The splicing process parameters should be reasonably adjusted according to different varieties and the usage conditions of old and new twisters to obtain better splicing effects; various preventive inspections of splicing quality and equipment status should be carefully done. The technical advantages of mechanical twisting and splicing can be better utilized.
The status and role of mechanical twisting and splicing technology
With With the advancement of science and technology and the continuous emergence of new yarn varieties, modern textile production has put forward higher and higher requirements for knot-free ends. Automatic winding machines are used to change yarn knots from mechanical knotting of ordinary winding machines. It is in the form of splicing. A major advance has been made. As a result, the proportion of knot-free yarn increased from 58% in 2005 to more than 80% in 2014. Currently, there are two widely used splicing technologies: air splicer and mechanical splicer. Air splicers have been widely used in the weaving industry, and mechanical splicing has been increasingly valued because it is closer to yarn splicing characteristics.
The mechanical twisting and twisting technology introduced by SAVIO Company uses mechanical actions to perform the untwisting and twisting process, and is realized by using a mechanical twister on the automatic winding machine. A technique for splicing bobbins. Its knots are of good quality and strong. In particular, it is of great significance for the production of fine and high-density fabrics to reduce yarn breakage, improve loom efficiency, and improve fabric quality.
The winding joint directly affects the splicing strength and appearance of the yarn. The most basic principle of the splicer is: first untwist the yarn end in reverse, so that the yarn at the broken end is in a loose single fiber state, then overlap and interlock the fibers, and finally twist. The gathered yarn is not easy to untwist due to its tight and smooth yarn structure and good hairiness conformability. In this way, during the jointing process of the two sections of yarn fibers, there will be poor cohesion between the fibers and they will easily slip off. With the continuous development and promotion of compact spinning technology, mechanical twisting is increasingly used for splicing compact spinning yarns.
Our company mainly produces high-grade pure cotton combed fine-gauge gathered yarn, most of which are used in woven clothing fabrics. Among them, the yarn-dyed fabric has clear particles and less hairiness. Good gloss, good wear resistance and smooth feel. When making non-iron fabrics, the strength of the fabric will be reduced by 30% to 50% after non-iron finishing, and ordinary ring-spun yarn cannot meet this high quality requirement. The gathered yarn has high strength, and mechanical twisting and splicing can further improve the appearance and strength of the knots, and better meet the yarn requirements for non-iron fabric processing. Our company began to use mechanical twisting of knotless veils in 2004 and has a history of more than ten years. Through feedback from the post-process and production usage, some experience has been explored. This article mainly talks about the use of mechanical twisting of fine-gauge yarn.
The working principle of mechanical twisting and twisting technology
Mechanical twisting produced by Italian SAVIO company The splicer is a splicer that operates purely on mechanical principles. It can control and guide the yarn at various stages to complete the entire splicing process.
2.1 The main components and functions of the mechanical twisting splicer
Front cover: The large suction nozzle grabs the bobbin and the small suction nozzle grabs the bobbin and is introduced into the splicer. Before placing the yarn, the large suction nozzle opens the front cover through the linkage mechanism. After the splicing is completed, the front cover is closed.
Outer clamp: There are two outer clamps, one at the top and one at the bottom. Its function is to stretch the two yarn ends to be spliced.
Clamping clamps: The function of the clamping clamps is to use their movement to determine the yarn required for the splicing disc, and to open the excess yarn through the clamping clamps to discharge the yarn ends. .
Twist-stop device: The main function of the twist-stop device is to separate the intact yarn from the ends to be pulled out, and stop it in the twisting plate before twisting. preparation work.
Twisting disc: The twisting disc is composed of a disc with a rubber surface and grooves on the concentric circles inside. It is driven through a connecting rod to complete the twisting action. The untwisting and twisting work of the yarn is completed in two self-compensating and interactive twisting interrogations. It can be suitable for splicing yarns of different finenesses, and even waxed yarns will not affect normal splicing.
2.2 The working principle of mechanical twister
Mechanical twisting The working principle of the machine is: first untwist the yarn, then stretch and thin the fiber, and finally twist the two sections of fiber. Its working principle steps are shown in Figure 1.
Step (a): Under the action of the large and small suction nozzles, place the yarn strips at both ends parallel to the splicing plate and open the front cover;
Step (b): Rotate the twisting disc to untwist the yarn tails at both ends, and clamp the upper and lower outer clamps to straighten the yarn;
Step (c): Pull the pliers to bring the yarn ends together, and the excess yarn ends are cut off. At the same time, the comb inside the splicing disc is activated to clamp the yarn.
Step (d): Twist the comb inside the splicing plateand shearing conditions, so that you can easily check the splicing quality of each spindle position. For example, if a certain spindle position has a lot of splicing times, poor splicing quality and a lot of shearing, it can be easily seen through online monitoring. In this way, problems with the splicer can be discovered in time and dealt with promptly.
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The yarn structure of trapped yarn is special, from twisting In terms of appearance, mechanical twisting is better than air twisting, and the knotted fabric surface performs better. However, the choice of the twisting method depends on the purpose of the yarn and the subsequent processes. Mechanical twisting has a high density of knots. When making knitted fabrics, the knots are often hard and the fabric surface will have thick spots, so it is not suitable for knitting. Use yarn. The twisted knot has a smooth appearance and high strength, and is suitable for woven yarns. Judging from the current usage of varieties, mechanical twisting is suitable for woven yarns and plain fabrics with yarn numbers below 11.8tex.
Conclusion
(1) Mechanical rolling and twisting technology has It has the advantages of excellent appearance, high knot strength, and wide adaptability. It has good adaptability to fine cotton yarn, cotton-spandex core-spun yarn, especially higher-grade gathered yarn, gathered siro yarn and other varieties. With the continuous development of compact spinning technology, mechanical twisting and splicing technology will receive more and more attention.
(2) Mechanical twisting is a technology that uses mechanical action to complete yarn twisting, which is achieved by configuring a mechanical twister on an automatic winding machine. The selection of splicing parameters is crucial to the quality of splicing. The three twisting process parameters of untwisting, stretching and twisting should be reasonably adjusted according to different varieties and the usage conditions of old and new twisters to obtain better twisting results.
(3) The maintenance cost of mechanical twisting equipment is relatively high, and the adjustment of splicing process parameters is relatively complicated. It needs to be adjusted spindle by spindle to ensure the consistency of knot quality. It is necessary to carefully carry out preventive inspections of splicing quality. Dedicated personnel are sent every week to sample and pattern the spliced yarns to check the appearance of the splices and repair any defective spindles promptly; the knot strength is regularly tested, and the knot strength must reach more than 90% of the original yarn strength.
(4) Mechanical rolling has high requirements on the status of equipment. We must attach great importance to various equipment management work, establish a complete and strict equipment management system, and formulate mechanical rolling Twist maintenance work method. Only by doing all the maintenance work in place, replacing wearing parts of the equipment in strict accordance with the cycle, and strengthening the preventive monitoring of splicing equipment can we better leverage its advantages.
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