In order to give full play to the carding function of card clothing, extend its service life, and ensure product quality, the judgment of card clothing failure, failure reasons, and conditions for card clothing replacement are introduced. It is proposed that electronic judgment of card clothing failure is the key for textile enterprises. expect. It is pointed out that in actual production, the working status of the carding machine and card clothing should be understood in time, test data should be collected from the five aspects of man, machine, material, environment and method, cooperate with dynamic management, and the failure of card clothing should be correctly judged and replaced in time. Able to ensure product quality and improve customer satisfaction.
01 Card Clothing Failure Judgment and Original
1.1 Card Clothing Failure Judgment
The card clothings for carding machines are installed separately in the pre-separation The sharpness of the comb bar cover, licker-in, fixed cover, cylinder, doffer, and rotary cover directly determines the quality of the sliver. The cotton mill’s judgment on the card clothing failure problem comes down to the sharpness and surface roughness of the card clothing. Feel the sharpness of the card clothing with your hands and divide it into 5 levels: the needle teeth are sharp and feel sticky and tingling, which is the top grade card clothing; the needle teeth are sharp and have a tingling feeling, which is the medium and upper grade card clothing; A card clothing with sharp teeth and a prickly feel is a medium-grade card clothing; a card clothing with a slight sharpness and a sense of forward and reverse directions is a medium-low-grade card clothing; a card clothing that is slippery and has a sense of forward and reverse directions is a low-grade card clothing.
To evaluate the sharpness of card clothing, the entire cylinder, doffer, flat plate and licker-in width shall be considered. According to authoritative literature: when the width of linear damage to cylinder clothing is not greater than 0.3 cm and the width of linear damage to doffer clothing is not greater than 0.2 cm, the quality of cylinder and doffer clothing is still qualified. Judging the quality of card clothing through the senses is the most direct method, and you can quickly know the condition of the card clothing. In production, the sharpness and surface roughness of the card clothing on the carding machine have been judged by the senses to be medium to low. However, because the cylindricity of the card clothing tooth tips on the entire machine is quite good, the correction of the gauge is quite standard and ensures It ensures the consistency of the left, middle and right spacing during machine production, meets the process requirements, and the indicators are relatively stable.
Although some carding machines have replaced the card clothing due to unstable sharpness and surface roughness indicators of the card clothing, the product indicators have dropped after replacement, and the carding card has been protected. Not only is it a waste of manpower and material resources, it also reduces the enthusiasm of security workers and loses their confidence in work. The author believes that judging the sharpness and surface roughness of the card clothing through the senses to determine whether the card clothing has failed cannot meet the needs of production management.
1.2 Causes of Card Clothing Failure
The low precision of manufacturing equipment is the main reason for the failure of card clothing. With the continuous improvement of equipment manufacturing processes and the widespread application of new materials, aluminum alloy rotary cover plates, fixed cover plate frames, and simplified rollers have been put on the market as mainstream products, but there are still many problems. Only by selecting appropriate materials and improving the manufacturing accuracy of equipment can we effectively prevent card clothing failure. At the same time, we must also take into account the construction of the technical talent echelon to achieve an effective combination of quality and cost of use.
1.2.1 The manufacturing precision of the cover frame is low
The cover frame is divided into two types: cast iron and aluminum alloy. Although the material quality is excellent, during the coating process, due to process differences or different equipment conditions, the flatness of the bottom surface of the cover frame becomes worse. Measure the left and right deviations. It can even reach 0.51 mm; some well-known manufacturers promise to control the deviation to a standard value of 0.08 mm, but they still cannot guarantee the flatness of the coated card clothing and the accuracy required by the machine process.
1.2.2 The tensile strength of the cover chain is insufficient
The covers of mainstream products on the market Plate chains are made of steel, aluminum alloy, etc. The user requires the flat chain to have a long service life and high tensile strength to avoid deformation, breakage, wear and other problems caused by the connection between flat card clothing and cylinder card clothing, which reduces product quality and increases production costs.
1.2.3 The cylinder has low cylindricity or the bottom surface of the cover has low flatness
Cylinder The cylindricity of the cylinder, doffer and licker-in determines the cylindricity of the covered card clothing. The cylindricity of the cylinder and the flatness of the bottom surface of the cover plate are required to be 0.02 mm. After wrapping the card clothing, they are required to reach 0.03mm. When the manufacturing accuracy of the manufacturer cannot meet this requirement, the use requirements of wrapped card clothing cannot be guaranteed.
1.3 Electronic judgment of card clothing failure
In actual production, security workers are maintaining equipment It is impossible to stop the carding machines one by one and test the card clothing every day. The usual method is to only test when the indicators are unstable, which will cause a large number of unqualified card slivers to flow to the next process. With the continuous development of information technology, online detection has emerged and is the most effective. Online testing is to install testing equipment directly on the production line, and conduct real-time monitoring and feedback through measurement technology to guide production and reduce unnecessary waste.
Although online detection and control technology can achieve direct control of product quality, it is difficult to measure product quality variables online in real time, and manual analysis is far from possible due to serious time lag. fulfil requirements. In addition, due to differences in the technical level and feel of the workers, manual adjustment of the gauge will cause some problems: if the gauge is tight, needle connection problems will occur; if the gauge is loose, the card clothing will be damaged. To this end, textile companies hope to be able to adjust the distance through electronic equipment to maximize equipment performance, reduce staff, and reduce production costs.��.
02 Card Clothing Replacement Conditions
Card clothing cannot be replaced solely based on its sharpness and surface roughness. To judge whether it has reached the middle or lower level of replacement, or when the replacement cycle (500 t or 800 t) has been reached, it requires comprehensive consideration, overall management, and comprehensive judgment based on test data and working methods, mainly on people, machines, materials, environment, Analyze the five major factors.
2.1 Sensory testing to determine the working status of card clothing
Establish an equipment usage ledger, record the working status of each carding machine, and classify the status of card clothing. Managers and security workers must be well aware of this. Excellent operation management and excellent operators play a decisive role in the care and maintenance of card clothing. Good operation training can improve the technical level of workers and extend the service life of card clothing.
2.2 Correctly judge the equipment status
The good operating status of the carding machine depends on multiple links Decisions such as autolevelling, drive systems, processes, etc. If there is a problem in any of the above links, such as inconsistent left, middle and right spacing, poor self-levelling, etc., it will cause the manager to make wrong judgments on the status of the card clothing.
2.3 Pay attention to the stability of raw material quality
Stable raw material quality will prolong the use of card clothing life. If the raw materials change frequently, the card clothing needs to constantly adapt to the raw materials, and changes in quality indicators such as impurities and short lint will also cause damage to the card clothing.
2.4 Stabilize the workshop environment and analyze test data
Stable temperature, humidity and dust filtering in the workshop Good use of cloth plays a key role. If the humidity in the workshop is too high, it will cause the card clothing to rust. If the humidity is too low, it will cause the lint to be too high and fly too much, causing the air suction device to be clogged and malfunctioning, thus causing damage to the card clothing. In addition, the test data directly reflects the operating status of the carding machine and card clothing. The replacement of card clothing should be determined based on whether the test data can meet the indicators required by the customer.
Conclusion:
In order to give full play to the carding function of the card clothing and extend its service life, in In actual production, it is necessary to understand the working status of the carding machine and card clothing in a timely manner, collect experimental data from the five aspects of man, machine, material, environment and method, cooperate with dynamic management, correctly judge the effectiveness of the card clothing and replace it in time, and Comprehensive consideration of production costs to achieve the purpose of improving product quality and improving customer satisfaction. </p
