The condition of the card clothing of the carding machine is a prerequisite for determining the carding effect of the carding machine, so the maintenance of the carding clothing is a very important task. It not only directly affects product quality, but also affects economic benefits due to the high price of card clothing. This article only analyzes and summarizes the maintenance of card clothing as follows.
The most basic principles of maintaining card clothing
It is necessary to perform maintenance in a timely manner according to a certain period. Do not wait until the card clothing of the cover plate, cylinder, etc. is excessively worn before repairing it. Perform light repairing according to a certain period. The grinding effect is better than the grinding effect after excessive wear of the card clothing. If the card clothing has been severely worn, it will be difficult to correct the worn tooth shape through grinding.
The most fundamental purpose of card clothing maintenance
is to ensure that the lick-in roller , cylinder, rotary flat plate, fixed flat plate, doffer, pre-carding plate and other card clothing have sharp tooth tips. The card clothing of the licker-in roller and pre-carding plate cannot be ground and should be replaced periodically to ensure the carding effect and prevent accelerated wear of the card clothing such as cylinders and rotary flat plates.
When grinding or replacing card clothing, it should be done one by one. Do not grind or replace the same group (several carding machines supplying the same draw frame) at the same time. card clothing of multiple carding machines to avoid large fluctuations in yarn quality indicators. In addition, during the production process, the same variety of card slivers from different carding machines are mixed and used on the draw frame, so that the quality indicators of the finished yarn can be kept stable.
The maintenance cycle of card clothing
can be based on the card sliver quality index (The number of neps), the sliver output, and the wear of the needle teeth using a microscope are used as benchmarks. Usually, these three methods need to be combined to determine whether the card clothing needs maintenance or replacement.
(1) Based on the output of card sliver: the maintenance cycle of card clothing is based on the output of carded sliver, such as the alloy steel cylinder and rotary cylinder recommended by GRAF The maintenance cycle of cover card clothing is: first grinding when 100 to 150 tons; second grinding when 180 to 270 tons; third grinding when 240 to 380 tons; fourth grinding when 300 to 480 tons The first grinding is carried out; the final grinding is carried out when the spinning speed is 350 to 550 tons; the card clothing is replaced when the spinning speed reaches 600 tons.
(2) Based on card sliver quality: set based on the average nep quality level of the textile mill (based on the number of neps detected by hand or the number of neps tested by AFIS instrument) Set the allowable baseline, and perform card clothing maintenance on carding machines that exceed the baseline. When maintaining card clothing based on card sliver quality (number of neps), the principle of setting the maintenance cycle is shown in the figure below.
(3) Based on microscope observation: Use a microscope (magnification ≥30 times) to observe the wear condition of the card clothing, and decide whether to Carry out card clothing maintenance. In addition, because the spinning raw materials, spinning count, yarn quality requirements, etc. of each textile mill are different, the maintenance cycle and service life of the card clothing are also different.
There are many factors that affect the degree of wear and service life of card clothing, and spinning raw materials are a key factor. When the impurity content in raw cotton is high (especially when it contains sand), the wear of the card clothing is much faster than that of clean cotton. A large amount of matting agent is used on the surface of matt or matt chemical fibers, which causes increased wear of the card clothing. Some chemical fibers are dyed with dyes, which will increase the wear of the card clothing.
Precautions when performing grinding and maintenance of cylinder card clothing
(1) High carbon steel cylinder clothing: High carbon steel cylinder clothing can be ground using traditional rotating reciprocating grinding rollers. When grinding needles, the grinding roller and cylinder cylinder must be parallel. Grinding should be as light as possible to produce a minimum spark length. If the grinding length is too long, the sparks will increase, which in severe cases will affect the carding effect, shorten the service life of the card clothing, and even cause damage to the card clothing.
(2) Alloy steel cylinder card clothing: For the grinding of alloy steel cylinder card clothing, it is recommended to use new reciprocating grinding equipment using flexible grinding materials. Grinding.
Precautions when performing needle grinding maintenance on doffer card clothing
For doffer clothings, resharpening is only possible if there are problems with transferring and holding the fibers. When carding artificial fibers with rough surfaces, doffer clothing needs to be polished to prevent the fibers from slipping. When the doffer fails to transfer fibers from the surface of the cylinder, the doffer card clothing needs to be repaired. Doffer card clothing can only be sharpened lightly, otherwise the fine tooth tips will create hooks, making it difficult for the stripping roller to transfer fibers from the doffer surface.
Precautions when performing needle grinding maintenance on the rotating flat card clothing
(1) Grinding the rotary flat plate on the carding machine: When grinding the rotary flat plate on the carding machine, attention must be paid to ensuring that the grinding roller is parallel to the flat plate so that the entire plane of the flat plate can be ground. During the needle grinding process, sparks should be generated across the entire width. Otherwise, the parallelism between the grinding roller and the rotating cover plate needs to be readjusted. The purpose of needle grinding is to regenerate a sharp edge at the needle tip. If the degree of grinding is not enough, it will not be able to produce a sharp enough edge. As a result, the number of neps in the raw sliver after needle grinding cannot meet the requirements, and the number of neps will be relatively short. rise again within the time period. If the grinding is excessive, more needle points willIf it is worn away, the service life of the card clothing will be greatly shortened. During the grinding process, you also need to pay attention to the fact that the pressure cannot be too high, otherwise a lot of burrs will be produced, which will affect the use.
(2) Grinding the rotary flat plate on the flat plate grinding machine: If the textile factory does not have the equipment to grind the rotary flat plate on the carding machine, the rotary flat plate can be removed. Grinding is performed on the cover plate grinding machine. </p
