Common problems in the combing process include poor cotton mesh, holes, poor joints, etc., which have a great impact on product quality and have become a key issue for relevant technical personnel of textile enterprises.
Poor cotton mesh edges
Poor edges of the cotton web include burrs, loose edges, broken edges, skirts, etc. They, together with holes in the cotton web and poor jointing of the cotton web, directly affect the quality of combed semi-finished products and should be strictly prevented.
1 phenomenon
Both sides of the cotton web output from the separation roller are not smooth and uneven. Some of the cotton fibers on the two edges are messed up by the cotton collecting hook tips to form spider-like broken edges; some edges have an obvious longitudinal sparse path; The edges of some cotton webs are wrinkled like skirts when being exported; some edges have periodic curled fiber bundles, and in severe cases, the edges of the cotton webs may even become smaller and narrower. This phenomenon directly affects the unevenness and unevenness of the cotton slivers on the car surface. Uneven weight.
2 Reason Analysis
1) The gap between the front edge of the nipper plate cotton collector and the upper nipper lip is too large, causing the cotton layer to be in the shape of a beard after the upper and lower nipper plates are engaged. Since the fibers on both sides of the beard shape are loose, it is easy to form cotton nets after being combed by the cylinder comb needle. Poor edges.
2) The installation position of the cotton collecting hook of the separation roller is inaccurate. When the installation is too low, the tip of the cotton collecting hook will puncture the cotton net, or even divide the cotton net into a line. The opening of the cotton collecting hook is too wide or too narrow, which will affect the cotton. Poor web edges. If the opening is too wide, it will not be able to collect and extract, and the edges of the cotton mesh will be loose and the hair will be broken. If the opening is too narrow, the cotton mesh will overlap and thicken at the edges of the cotton mesh.
3) If the temperature and humidity in the workshop are inappropriate, especially when the humidity is higher than 70% or lower than 55%, the rubber rollers or rollers will easily lift up the edges of the cotton web, causing serious deterioration of the edges of the cotton web, and even causing the rubber rollers or separation rollers to wrap around.
4) When processing short fibers on a high-speed machine, the two sides of the cotton web will sag between the two separation rollers because the separation rubber roller cannot hold it or the separation roller bridge gear is loose.
5) There is a small amount of entanglement on both sides of the rubber roller or roller, which causes the separation jaw to hold the cotton web poorly and causes broken edges.
6) The short fiber of raw cotton and the poor control of the triangular airflow plate can easily cause loose edges of the cotton net.
3 maintenance methods
1) During large and small flat lathes, the front edge of the nipper plate cotton collector should be as close as possible to the inside of the upper nipper lip.
2) The cotton collecting hook of the separation roller should be installed according to regulations, and the height should be consistent with the opening. The surface of the cotton collecting hook should be kept smooth and free of burrs and cotton wax.
3) Strictly control the temperature and humidity of the workshop.
4) The pressure on the separating rubber roller should be increased on the high-speed machine to ensure good grip on the separated whiskers.
5) Check whether there is any tangle on both sides of the separation roller or rubber roller.
6) The separation roller bridge gear and the front and rear separation roller head gears are properly meshed with each other, and the front and rear tensions are consistent; after calibration, the countershaft handwheel should be rotated slightly in reverse order so that the separation roller can rotate reversely and normally normally.
7) For short fibers, you can appropriately reduce the opening of the clamp plate and cotton collector, and slightly loosen the triangular airflow plate by 0.5 mm, which can solve some loose edges.
Holes in cotton net
Holes in the cotton web are caused by horizontal unevenness of the cotton web. Cotton nets with holes have a major impact on the uneven dryness and weight of cotton slivers on the car surface. If such phenomena occur during production, the machine should be shut down immediately for maintenance.
1 phenomenon
When the separation cotton web is conveyed from the separation jaws, there are cat-eye-shaped holes of different sizes. Some cotton mesh holes are quite regular and appear in every clamping cycle; some are basically at the same position in terms of the location of the rupture; some are irregular and only appear occasionally.
The appearance of a broken cotton mesh will become hairy, wrinkled, or have obvious uneven thickness and other undesirable conditions. If you twist a cotton sliver with your hands, you can immediately detect uneven thickness of the sliver. If the cotton mesh is seriously broken, long fibers will appear in the waste cotton mesh on the surface of the dust cage.
2 Reason Analysis
1) The holes in the cotton mesh are cyclical and appear every time the car is clamped. The cotton mesh does not break when the car is driving at a slow speed. When the vehicle speed is normal, holes will appear in the cotton mesh immediately. This situation is mainly caused by too much separation between the brush and the triangular airflow plate, causing the brush to generate airflow overflow during high-speed rotation, disrupting the separation and jointing of the whiskers.
2) If the rupture position of the cotton mesh is always at the same place, it may be that the lips of the upper and lower pliers are seriously impacted by debris.
3) The cotton mesh is torn and broken, and some are even damaged about an inch long. This phenomenon is mostly caused by the inability of the separation jaws to effectively hold the beard. The separation jaws hold The factors of force difference can be analyzed from the following points:
1) The surface hardness of the nitrile separation rubber roller is too large and the elasticity is poor, which results in the reduction of the clamping area of the cotton web by the separation jaws, and the holding force of the fiber is correspondingly smaller.
2) The surface flatness of the nitrile separation rubber roller is poor, and the axial eccentricity and bending exceed the regulations, which is also a main reason why the separation whiskers cannot be held.
3) The outer diameter of the separation roller groove is significantly different on the same section, or the roller is severely bent.
4) The separation roller or separation rubber roller is wound around, causing the separation jaws to not bite tightly, affecting the grip.
3 maintenance methods
1) Improving the hardness of the separation rubber roller and increasing the clamping force of the separation jaws is an important method to eliminate holes in the cotton web. Now some factories use rubber rollers with a hardness lower than 70 degrees, which is more effective.
2) Stack the two inner and outer separation rubber rollers and check whether there is any concavity on the surface of the rubber roller. If light can be transmitted through the middle, it means that one or both of them are bent and should be replaced immediately.
3) The airflow of the brush should be strictly controlled. In particular, the brush and the triangular airflow plate should not be empty too much. Generally, it is appropriate to be tangential. If the airflow breaks through the cotton mesh, the triangular airflow plate can be moved downward appropriately to ensure that the cotton mesh does not break.
4) Always check whether there are embedded debris or cotton wax in the upper and lower pliers lips, especially when processing cotton with high sugar content in summer. Clean the debris or cotton wax from the lips of the pliers promptly.
5) The surfaces of the rubber rollers and rollers should be kept clean and free of burrs to prevent circular winding of fibers. If the outer diameter of the separation roller groove is found to be thick, it should be replaced in time. When the separation roller is bent, it should be straightened in time.
4 precautions
1) The separation rubber roller should have a regular replacement and maintenance system to ensure the condition of the rubber roller.
2) The inner and outer separation rubber rollers should be used separately (the quality of the inner row of rubber rollers is higher than that of the outer row). During use, the rubber rollers should be regularly sharpened and eccentrically corrected, and corresponding handover procedures and assessment systems should be in place to ensure the quality of the rubber rollers.
3) When the machine is parked for a long time, all rubber rollers should be released to prevent deformation of the rubber rollers.
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