Self-winding yarn with back yarn

Self-winding yarn with yarn return is a headache that textile companies often encounter during the production process. The yarn return is likely to cause yarn breakage during the warping process of the package yarn, which seriously affects the warping efficiency. So what are the reasons for the occurrence of rewinding? How to reduce rewinding?

1 Cause

1) The yarn is chaotically formed by the large suction nozzle to form a yarn back. During the warping and unwinding, the tangled yarn is brought up. Because the yarn cannot be unwound, the yarn is broken near the surface of the package, forming a broken end and affecting the warping efficiency.

2) Since the electric clearing yarn and yarn breakage occur at the same time, the yarn breakage occurs somewhere between the tank and the electric clearing. This section of the cut yarn will bounce and fall above the electric clearing On the flat plate, when the next splicing action of the yarn is completed, this section of yarn is easily entangled in the bobbin and becomes the yarn return when the grooved barrel is started.

3) Due to the poor strength of the yarn and too many weak loops, the tension break of the yarn occurs below the splicer. After the yarn breaks, it bounces irregularly and loosely hits the small end of the paper tube. In the process of finding the head of the large suction nozzle, the bobbin reversed and wrapped the yarn on the small end of the paper tube firmly around the small end of the paper tube. If the large nozzle first finds the head without breaking the yarn wrapped around the small end of the paper tube, then the large nozzle will go up to find the head for the second, third or even fourth time. During the process, the yarn wrapped around the small end of the paper tube will be broken. After the yarn breaks, two heads are produced, one of which is taken down by the large suction nozzle, twisted together with the lower yarn head brought up by the small suction nozzle in the splicer, and the groove is started to complete a splicing process . In this splicing process, or in the next splicing process, the return yarn left on the small end of the paper tube is easily brought into the package to form a return yarn, and one end of the return yarn is shallowly attached to the package, and the other end is still Wrapped around the small head of the paper tube.

2 Solutions

1) To solve the problem of large nozzles sucking chaotic yarns, we must first ensure that the large nozzles move upward to find the success rate of the upper yarn end. It is necessary to observe the situation where the large suction nozzle finds the yarn end, and to observe all the spindles of all winders producing this variety. The success rate of the first suction nozzle for the first time to find the head must be guaranteed to be above 99%.

2) If it is less than 99%, it can be improved from the following aspects: adjust the distance between the large nozzle and the package according to the standard; check the length, roundness and hardness of the paper tube, and discard those Unqualified paper tube; there are three gears available for reverse drive of the trough, which are fast, medium and slow. Experiment according to these three situations to see which one has the best headhunting effect. Drive acceleration can also be selected, and experiments are conducted for different accelerations to select the optimal process to start the machine; secondly, as long as the success rate of finding the yarn end is guaranteed, try to set the number of times of the large nozzle to the minimum . Because the more times the large suction nozzle finds the head, the greater the chance of confusing the yarn. The more suction times, the yarn on the surface of the package will be sucked and chaotic. At the same time, adjust the number of large nozzle movements and splicing times accordingly.

3) Solve the problem of electro-clear back yarn from three aspects: first, improve the cotton blending to reduce the strong and weak loops on the yarn, thereby reducing the breakage at the contact between the groove and the barrel; second, strengthen the interior of the production workshop Management of equipment, temperature, humidity and operation to prevent the occurrence of sporadic yarn defects, optimize the process of pre-spinning and spinning, and reduce the number of times of electro-clear yarn cutting; third, the yarn catcher should be done at least once every 5 days Thorough cleaning ensures that the yarn catcher is not blocked, and the yarn can be sucked back anytime, anywhere.

4) For weak loops, the first thing is to reduce the strength of weak loops. In the company's cotton distribution, replace the raw cotton with low single fiber strength, and replace it with high strength raw cotton, so that the minimum strength of the single yarn produced has An obvious improvement. At the same time, the winding speed can be reduced, the spinning speed is reduced, the tension generated during the spinning process will be significantly reduced, and the generation of yarn return can also be reduced.

5) For weak loop yarn, a balloon tracker can be used on the single spindle of the winding cone, which can greatly compress the balloon produced when the bobbin is unwound, significantly reducing the contact area between the yarn and the air, and directly reducing the spinning Yarn tension to reduce the occurrence of yarn return. In addition, under the condition that the success rate of finding the yarn end is guaranteed, the process parameters of the automatic winder are optimized, the number of failures of finding the yarn end is changed to 1, the action of the large nozzle is changed to 1, and the package "delayed up" is used 10 times , 10 times for "Looking for the upper yarn end", and 1 for the number of splicing failures. The reason why the above process parameters are used is to realize that the end of the wire wound around the small end of the paper tube floats in the air. Before being wound into the bobbin, the single spindle of the automatic winder can light up the red light and can stop. In this way, the blocker will have the opportunity to pull the wire wound around the small end of the paper tube and pull it out by rotating the bobbin, so as to achieve the purpose of eliminating such wire back.

3 Operation points

Do "four look one head". See if the bobbin or "yarn" is produced at the foot of the spindle. If it is a bobbin, use the corresponding button on the single spindle to replace the bobbin under the yarn extraction unit. Second, see if there is a loopback at the small nozzle. If it is, the driver needs to remove the loopback. Third, check whether the splice is hanged at the splicer. If it is, clean it. 4. See if there is a yarn return in the yarn clearer channel. If so, find a way to clean it up. "One head search" means that after the single spindle turns on the red light and the alarm stops, the driver must use his hand to find the head on the bobbin instead of extinguishing the red light directly to start single spindle production. The blocker looked at the left and right sides of the bobbin when looking for the head with his hand. If there is a looped yarn wrapped around the head, be sure to withdraw the looped yarn completely.

The application of "delayed head-hunting" will affect the output. Spinning companies can flexibly decide what kind of process to use according to their own requirements on output and quality, but before the new process is put on the machine, it must be tested to determine whether the process needs to be applied.