Yarn defects are an important problem that is difficult to solve in the spinning process. It seriously affects the quality of the yarn and also causes certain losses to subsequent processes. Generally divided into regular yarn defects and sudden yarn defects. Among them, sudden yarn defects include short slugs, nep impurities, increased hairiness and evenness defects. Most of these yarn defects are due to poor production management, poor operation, intact equipment, poor operating status of parts, and process design. Due to unreasonableness, such yarn defects are large but few, which have a significant impact on subsequent processes and fabric quality, so they must be removed. Reducing sudden yarn defects can be carried out from the following five aspects.
01 Properly configure process parameters
Carding process: Regularly check the tension status and wear of the drafting toothed belt and coiling toothed belt, and reasonably adjust the coiling tension to reduce congestion in the coiler. It can reduce the probability of breakage of the draw frame. For example, when the front spinning and carding cotton production line in the air-end spinning workshop is changed to a thicker production line, through process optimization, the relationship between ration, speed and cotton web tension is adjusted, reducing the number of carding breaks and joints, and improving carding production efficiency. , which not only reduces the labor intensity of workers, but also improves the quality of semi-finished slivers.
Drawing process: Appropriately reducing the nip gauge, roller center distance, and back area draft multiple of drawing and roving will help reduce the CV value of the spun yarn, but The prerequisites are the simultaneous development of holding force and drafting force, guiding force and control force, and normal drafting to prevent bad drafting caused by poor roving technology, defects in drafting elements and pressurizing mechanisms. Therefore, it is necessary to find an optimal combination of the nip gauge of drawing and roving, the roller center distance, the draft ratio of the back zone and the total draft ratio.
02 Strengthen operation and operation management
First of all, do a good job in cleaning , Reduce the impact on the quality of the yarn sliver due to unclean machine, flying particles attached to the yarn sliver, winding mechanism, etc. If the machine cleaning is seriously poor, occasional yarn defects may occur. Two aspects of work must be focused on: on the one hand, strict cleaning management. Some varieties must break the traditional method and implement a cyclic cleaning method, that is, do it in shifts, all the time, Keep the machine channel clean and free of debris; on the other hand, strengthen the management of cleaning tools, use tools correctly, strictly clean operation methods, eliminate the phenomenon of slapping, beating, fanning and blowing, and reduce the occurrence of yarn defects. When spinning pure polyester or blended products, due to the oil-containing polyester chemical fiber, the yarn channel is prone to accumulation of oil and entanglement, causing the cotton sliver to become hairy. Drawing is prone to blocking the bell mouth and coiled inclined tube, so regular maintenance and scrubbing is required to ensure that the channel is smooth. , No hanging blockage.
Secondly, we should vigorously improve the operating level of the turn-stop workers, strengthen operational training and knowledge training, strengthen operational patrols, improve the initiative, enthusiasm and regularity of operations, and pay attention to during patrol operations. Prevent and catch defects. Strict reverse inspection and implement defect prevention and defect catching assessments. In addition, operation management must also pay attention to errors and abnormalities that occur during the production process.
03 Strengthen equipment maintenance and repair
In terms of equipment, focus on the maintenance of each process channel. The scrubbing work, whether the machine is started or stopped, must be maintained regularly and in good condition to ensure that the quality is up to standard when it is started at any time. The operating status of the equipment directly affects product quality. During the production process, sometimes quality problems such as fine yarn drying may occur due to wear and tear of bearings, gears, etc. It is necessary to strengthen the periodic maintenance, inspection and daily maintenance of the host equipment. Each branch factory and each work section must strictly follow the maintenance cycles specified by the company, formulate a monthly operation plan, and perform equipment maintenance according to the operation plan. Each branch factory and work section conducts monthly inspections and assessments on maintenance machines according to the person responsible and the work plan. The company puts forward corresponding requirements based on the inspection situation every month, and supervises and guides the inspection work of the branch factories and work sections.
04 Strengthen temperature and humidity management
The temperature and humidity control of each process should meet the needs of the spinning process. The fiber absorbs and releases moisture requirements, so that the fiber is in a moisture release process from blowroom to carding, a moisture absorption process from carding to coarse yarn, and a weak moisture release process from coarse yarn to fine yarn. Prevent high temperature and humidity in summer, and pay attention to heat preservation in winter. When parking for a long time before driving, the workshop should turn on the air conditioner in advance and preheat it before driving. Strengthen temperature and humidity control, reduce regional differences in temperature and humidity in the workshop, and prevent occasional yarn defects caused by regional fluctuations in temperature and humidity or extreme external environmental conditions.
05 Reasonable setting of winding machine yarn clearing parameters
First of all, we must give full play to the winding machine The process electronic yarn clearer has the function of removing yarn defects, but production efficiency, labor and cost consumption must be considered. On the basis of ensuring the normal production efficiency of the winding machine, reasonable setting of yarn clearing parameters can improve the effect of removing harmful yarn defects, and ultimately better meet the user’s quality requirements. Secondly, make good use of the data from 100,000 meters of yarn defect detection as a basis for adjusting the yarn clearing process.
In addition, for the removal of yarn defects, it is also necessary to find out the causes of raw material yarn defects, drafting yarn defects, and operation and management yarn defects based on the distribution and number of yarn defects in 100,000 meters. The root causes should be controlled during the production process; however, we cannot completely rely on the electronic yarn clearer to remove yarn defects, which must be based on the fabric requirements.Determine reasonable yarn quality, find out the yarn defect requirements of different fabric structures, and adjust the parameters of the electronic yarn clearer to reduce the pressure on the electronic yarn clearer. </p
