With the continuous improvement of market requirements for yarn quality, various cotton spinning enterprises have increasingly higher requirements for yarn quality and Uster evenness level, and roller spinning mechanical waves have become the enemy of the textile industry. It will directly affect the appearance quality of the fabric. The causes and elimination measures of roller mechanical waves are as follows.
Causes of roller mechanical waves
1
According to the principle of using the lower draft roller in the drafting mechanism, the roller spinning mechanical wave occurs in the front area of the lower draft roller. At the position of the perimeter range πd, a raised peak appears, commonly known as a chimney. Its state is divided into harmful waves (peaks exceeding 1/2 of the fundamental wave) and harmless waves (peaks exceeding 1/3 to 1/4 of the fundamental wave) , slight wave (1/5~1/6 peak exceeding the fundamental wave) and normal waveform. The yarn requirements and indicators of textile mills generally do not allow harmful waves, while harmless waves should generally be controlled within 8%.
2
Improper installation and adjustment of the roller causes mechanical waves in the roller spinning. Because the spun yarn roller is being installed and adjusted, the roller seat is not adjusted well, and the height and entry and exit positions of the roller seat are different. Or during roller installation, when the front roller head section jumps too much, the force-aligned roller method is used, causing the entire row of rollers to bend and produce small waves. In use, it is inevitable that the roller spinning machine will not run smoothly and produce mechanical waves. At this time, the mechanical waves of the rollers mostly show that one roller generates mechanical waves for several consecutive spindles or the connecting part of two rollers generates mechanical waves, and most of them are harmful mechanical waves.
3
Roller cleaning, press-fit roller bearings, and improper assembly cause mechanical waves. When the rollers are being cleaned and the roller bearings are pressed, the guide holes and the end faces of the guide posts are not cleaned cleanly and filled with dirt, etc., which causes the connection of the two rollers to jump too much. When forced alignment is performed, the guide posts of the rollers are prone to bending and deformation. This causes the roller to run unevenly during use and generates roller mechanical waves.
4
The roller seat is empty. During the installation and adjustment of the roller, the roller seat is hollowed out and not solidified. After the roller is pressurized by the cradle, it will shake slightly during operation and produce roller mechanical waves. At this time, the roller mechanical waves usually occur at the roller joint part.
5
Roller material, surface quality, tooth profile errors, etc. caused by the roller itself Mechanical waves. The quality of roller raw materials, roller machining and manufacturing accuracy, surface quality, uniformity of roller working surface tooth shape, and connection accuracy can all cause roller spinning mechanical waves. Among them, the uniformity of the tooth profile of the roller working surface is the main factor that generates mechanical waves in roller spinning. Inconsistencies in tooth shape, tooth top width, and tooth depth on the working surface of the roller will directly affect the uniformity of drafting engagement, and it is easy to produce mechanical waves in roller spinning.
6
The quality of roller bearings causes mechanical waves in roller spinning. Due to the poor set accuracy of the end face verticality and circular runout of the roller bearing and the tight fit of the roller bearing hole and the roller guide post, the guide post is bent and deformed, resulting in poor roller operation stability and the generation of roller spinning mechanical waves.
Measures to eliminate roller mechanical waves
1
Improve roller manufacturing precision. The improvement of roller manufacturing precision plays an important role in eliminating mechanical waves caused by the roller itself. Comprehensive improvements in materials, heat treatment, tooth design, mechanical processing, surface treatment, etc. will help prevent the occurrence of serious mechanical waves and eliminate mechanical waves caused by the roller itself.
2
Choose the roller configuration appropriately. Mechanical waves in roller spinning are mainly caused by the front roller. Therefore, when the textile mill is supporting the spinning machine, the front roller must choose a roller without mechanical waves in order to eliminate the mechanical waves caused by the roller. At present, the mechanical rollers produced by roller manufacturers have high single-piece manufacturing accuracy, the circular runout of the single-section roller working surface is ≤0.015 mm, and have good interconnectivity.
3
Proper installation, adjustment and cleaning. Reasonable installation and adjustment are crucial to eliminate mechanical waves in roller spinning, especially severe mechanical waves. At present, the mechanical rollers produced by roller manufacturers do not need to be pre-aligned under the car. They should be directly connected to the machine. However, the roller seat must be calibrated before loading the roller on the spinning machine, so that the roller seat is in front, back, up, down, high, and straight. The low position is consistent, and the runout of the second section of the front roller head is ≤0.02 mm. Then put the cleaned front rollers on the roller seat and manually dock them one by one. Pay attention to using a soft cloth to wipe the dirt on the end face of the guide hole and the end face of the roller bearing during docking.
4
After all the rollers are docked, use the head-to-tail method and use the special roller Tighten the tools together with a torque of 78 N·m. After tightening, the roller seat will be knocked out. If there is a knock-out area, adjust the entry and exit position of the roller seat or lower it to solve the problem. After being hollowed out and solidified, 96% of the runout of the entire row of rollers was within the range of 0.03 mm.
5
Reasonable matching roller bearings. Select roller bearings with high precision and good quality, and select the roller bearing holes and roller guide posts to be matched in a sliding fit. This can avoid the bending deformation of the roller guide posts caused by over-tightening of the roller bearings, affecting the quality of the roller connection and resulting in spinning. Yarn mechanical waves.
6
Roller spinning mechanical waves are caused by many factors, eliminating roller spinning Mechanical waves are also a common goal of roller manufacturing companies and textile companies, so they must be manufactured by rollersOnly when enterprises provide high-precision, high-quality mechanical wave-free rollers, and with reasonable configuration, installation and adjustment by textile enterprises, can roller spinning mechanical waves be completely eliminated. </p