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How to Optimize Yarn Production

November 02,2023

In the process of yarn production, we often encounter various issues such as how to optimize the slubbing curve, what is systematic yarn cutting, how does the problem of broken ends occur during warping, how to set the knotting parameters, and how to solve the problem of net yarn in the automatic winder? These issues may affect production efficiency and yarn quality. Therefore, this article will provide detailed answers to these questions to help you optimize the yarn production process.

How to optimize the setting of the slubbing curve?

Answer: Optimizing the slubbing curve is a long-term process. The basic method is to first set a suitable slubbing curve based on the basic situation of the factory's yarn production. Next, adjust the electronic clearing process with the aid of the slubbing curve auxiliary point function, the electronic clearing defect detection function, the grading matrix scatter plot, and customer feedback information. Then repeat the above steps as needed until the electronic clearing process is optimized. The standard for an ideal optimized curve is that all harmful slubs and harmful foreign fiber slubs are detected and removed, very few or no harmless slubs and foreign fiber slubs are detected and removed, and the efficiency loss caused by clearing is minimized.


What is the concept of systematic yarn cutting?

Answer: Systematic yarn cutting mainly occurs for several reasons. The Loepfe control box continuously patrols and checks each single spindle's hardware and software for problems. When there is a deviation in the sub, it will activate the electronic clearing system to cut the yarn when necessary. Each time the electronic clearing cuts the yarn, it performs a tuning check and a clearing operation to prevent the detection of the fine yarn that continues to be wound from being affected by the pollution of the yarn path, resulting in sensitivity variation. For example, after the fine yarn joint is completed, if a foreign fiber cutting occurs immediately within a certain length, and it happens 2 or 3 times, 4 times consecutively (which can be set or canceled), Loepfe can determine that the probability of this consecutive occurrence is very low. It might be due to the change in the color or gray level of the raw cotton, and a new sample must be taken to compensate for the color difference, thus causing systematic yarn cutting for adjustment. This systematic yarn cutting signal can be given by the automatic winder if it deems necessary.

How does the breakage occur on the winding bobbin due to the presence of back yarn or messy yarn during the warping process?


The back yarn sprayed out during the robbing of adjacent spindles (in the case of blocked suction nozzles) directly drifts into the winding position after the cleaner.

Some yarn ends in front or behind the machine are blown into the cleaner by the moving fan.
The yarn end of the dropped bobbin is brought in by the bobbin being spun, usually happening when the yarn collector doesn't collect the yarn in time and the pile behind is relatively large.

The yarn end of the bobbin put on by the stop worker is not cut off.

The yarn tail left when the dropped yarn starts (wrapped around the big head of the paper tube for two to three rounds for the warping machine or knitting machine to connect) is too long or loose and gets in after being broken.

The operation method of the dropped yarn start is incorrect, and the yarn end spans the big head of the paper tube. When the warping stop worker finds the yarn end to connect, the other half becomes the back yarn stuck in the bobbin yarn.

The sub-brake device is not good and cannot lift or stop in time, making it difficult to find the yarn end. When the automatic connection is made, the big suction nozzle randomly sucks out a thread and connects it, causing the head to break when it is very winding, and it is thought to be back yarn attached when checking (breaking the continuous yarn).

Even if there is no chain problem in point 7, it is most likely to find a messy head when spinning high-count yarn, especially when connecting multiple times continuously and when the bobbin yarn tension is relatively loose (or mechanical reasons, or tube yarn reasons, causing continuous multiple connections).

The gap between the big suction nozzle or the start hook and the tube yarn is not good, causing the yarn grinding phenomenon.

4. How to set the twisting knot parameters, twisting code, and adding twisting code when making 16-70D spandex core yarn on 338? 

Our setting when doing 16-70D is 6 457, the knot that a single can hit looks pretty good, the strength can also pass, but when the whole car does this variety, the problem comes, its efficiency is only 58%, the repeat knotting times reach 150%, please ask the expert how to solve this problem, whether to make changes in knotting, such as digging pipes, pinching knot blocks, etc. Do you also need to change other parameters in the computer? We use serrated untwisting tubes, and the knot block is DZ3/16.1E

Answer: If the knotting effect of the Winding machine can be good on a single statistic, but not good on the whole machine, first consider whether the gas supply pressure can be up to standard, especially the actual air pressure on a single spindle. Generally speaking, the whole car's music can see the pressure gauge of the car head, but the jet pressure of the last mirror cannot be seen, you can analyze it from the sound of each jet. Another thing is whether the mechanical action surface is good, and whether the action of braving yarn and pressing yarn is in place. Generally speaking, electronic control can achieve the consistency of the whole machine, but mechanical use for a long time is more likely to deviate. The specific situation can be observed on the car. After ensuring that there is no error in the air pressure and mechanical aspects, consider the process index and knotting block problems. Generally, the untwisting effect of the toothed untwisting tube should be good. If you feel that the strength is not very good, you can also check the untwisting effect first. Please take down the knotting block and let it untwist purely. Look at the state after untwisting, and determine the state of untwisting by adjusting the air pressure and the jet angle of the untwisting tube. If there are other types of knotting blocks, after all the above items are done well, you can also try the effect of different knotting blocks. In addition, it should be noted whether the airtightness of the pressure yarn board when pressing the yarn is good.

5. How to solve the problem of net yarn appearing in the automatic winding machine?

Answer: The following parts should be checked for the phenomenon of net yarn and messy yarn layer in the automatic winding machine

Is the distance between the large suction nozzle and the bobbin less than 6mm (when the bobbin is 100mm at the small head end)

Is the negative pressure of suction greater than 42, try to adjust it to 38 (too small to suck the yarn)

Whether there are burrs or grooves at the suction mouth of the large suction nozzle, causing the yarn to fail to smoothly enter the knotter channel to knot during knotting, and repeatedly knotting

The deformation of the pressure yarn rod, the yarn is not sent into the knotter clamp plate during the knotting action, causing knotting defects, being cut by the electric cleaning or not knotting, knotting failure, repeated knotting

Check whether the knotting quality is qualified. Unqualified knot heads will be cut off and fail to knot after passing through the electric cleaning knot inspection channel, resulting in repeated knotting

Is the humidity in the workshop too low? The humidity in the workshop for adhesive raw materials should be more than 65%

Check if there are any back threads hanging on the tension plate

Is the tension adjusted reasonably

Sometimes there is tension, sometimes there is no, sometimes it is large, sometimes it is small The angle between the bobbin plane and the slot bobbin plane changes

In summary, do we need to consider and solve problems in yarn production from multiple angles? Optimizing the cleaning curve, understanding the concept of system cutting yarn, solving the problem of breakage during warping, setting the knotting parameters, and dealing with the problem of net yarn appearing in the automatic winding machine, do all these require us to deeply understand each link of yarn production, as well as the functions of various parameters and equipment? I hope the answers in this article can help your yarn production. Finally, do we need to remember that the solution to any production problem requires us to constantly practice and learn? Only in this way can we truly optimize the production process and improve the quality and production efficiency of yarn.