The drawing process is responsible for the tasks of merging, drafting, mixing, and sliver formation. It has the function of improving uneven long segments of cotton sliver and improving fiber hooks. However, some problems often occur during the drawing process, which affects the yarn. quality.
Draw frame weight eye difference
The problem of weight eye difference on the same machine is not only related to the manufacturer’s inadequate guidance, installation, and debugging of draw frame equipment technology. It is also closely related to factors such as improper use of adjustment equipment in spinning mills. Common reasons are as follows:
a) The bell mouth is too large, the pressure roller is deformed, the pressure roller bearing is damaged, The pressure roller is aged (grooved), the pressure spring of the front pressure roller is aged, and there is no oil between the pressure roller pressure spindle and the pressure spring.
b) The position of the bundler is downward or backward, causing some fibers in the cotton web to rush straight into the front wall of the inner cavity of the bundler, and then flip backward along the radial direction and rush along the back side. out; the feeding cans are randomly placed too far away, which will cause unexpected stretching of the sliver. The position of the cans should be marked on the ground and the operators should be supervised and educated to operate correctly.
c) The cotton guide ring is not in a horizontal state or the gap between the two slivers is too small, which causes excessive tension in the fed sliver, resulting in unexpected drafting of the sliver.
d) The diameter of the single-eye or two-eye rubber rollers is different or exceeds the use limit, which directly causes the eye difference; the pressure spring exceeds the specified period, the pressure mandrel is deformed, etc., causing pressure unstable.
f) The tilt of the pressure hook at the pressure position will not be repaired or the butterfly spring leaf has been damaged; the diameter of the bell mouth is inconsistent from left to right or the aperture is too large or too small.
g) The roller spacing in the draft distribution does not match the light and heavy teeth, and the tension adjustment is unreasonable; the pressure rod is deformed and misplaced; the pressure rod adjustment ring is inconsistent or deformed; The experimenter’s unstandardized sampling and weighing inspection methods often lead to repeated misadjustments, which can lead to the problem of drawing eye difference.
Defective strips with sandwich fiber bundles
Such defective strips are generally only discovered when they are produced on the roving frame and are highly concealed. Usually, when the roving frame is in normal operation, some spindle positions on individual machines suddenly appear to be unable to stretch and frequently break ends. Only after changing the machine and feeding sliver can the situation return to normal. After checking the faulty sliver, it was found that there were wrinkled fiber bundles at every other section in the sliver. The fiber bundles were neither flannel flowers, flying flowers, or dirty flowers attached, but were completely good fibers.
After inspection, the draw frame corresponding to the production was in normal condition. The spun sliver was evenly dry and had a good structure. The cause of the problem could not be found. After asking the lathe on duty, he learned Due to insufficient cleaning and inspection, one side of the front rubber roller was wrapped with a thick layer of floral clothing and was still being spun. The cleaning was not found in time. After cleaning, the defective strips that had been spun were not tracked and flowed to the subsequent process.
After repeated tests and analysis, as long as the surface of the front roller and front rubber roller is covered with more floral clothing, the spun cotton sliver will produce sandwich fiber bundle defects. This phenomenon generally occurs in It is easy to occur when the raw cotton contains high sugar content or the relative humidity in the workshop is high.
In response to this problem, it is necessary to improve the anti-winding and anti-winding performance of the rubber roller, keep the cleaning and wiping device of the bottom roller normal on the equipment, the upper cleaning flannel has a good effect, and focus on production Operate the cleaning cycle, improve the operator’s sense of responsibility, and promptly track and deal with any abnormalities found.
Drawing details
a) When drawing defects in details, you must first consider whether the transmission key is loose. Generally, when the key is loose, the wave spectrum Mechanical waves will be shown on the graph. Secondly, consider whether the tension draft, guide draft and coil draft are too large. If details occur in the rear area when starting, the method to check whether the key of the transmission part is loose is: hold the front roller with one hand and turn the pulley with the other hand. If there is obvious gap, the transmission part should be checked. It may be caused by loose keys, worn gears, etc.
b) According to production experience, when multiple vehicles reproduce car details, or multiple equipment occasionally and intermittently have details, the design of process parameters is in a critical state and is most likely to cause it. At this time, , the possibility of improper process design should first be considered. However, in actual production, drawing details may also occur due to both mechanical and process reasons, and sufficient attention should be paid to them. </p
