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. Caused by unreasonableness, such yarn defects are large and few, but they 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.
Reasonable configuration of process parameters
Carding process: Regular inspection of drafting toothed belts and loops The tension state and wear condition of the toothed belt and reasonable adjustment of the coiling tension can reduce the congestion of the coiler and at the same time reduce the probability of breakage of the drawing guide frame. For example, when the fine-count production line for spinning and carding in the air-end spinning workshop is changed to the coarse-count production line, through process optimization, the relationship between the basis weight, speed and cotton web tension is adjusted, reducing the number of carding breaks and joints, and improving the 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.
Strengthen operation and operation management
First of all, do a good job in cleaning and tidying up , to reduce the impact on the quality of the yarn sliver due to uncleanness of the machine, flying particles attached to the yarn sliver, winding mechanism, etc. If the machine is seriously poorly cleaned, occasional yarn defects may occur. We must focus on two aspects of work: 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, and keep the machine channels clean and free of debris. On the other hand, strengthen the management of cleaning tools, use tools correctly, and strictly implement cleaning operations to eliminate the phenomenon of beating, beating, fanning, and blowing to reduce the occurrence of yarn defects. When spinning pure polyester or blended products, due to the oil-containing polyester chemical fiber, the yarn channels are prone to accumulation of oil and are easily tangled, causing the cotton slivers to become hairy. Drawing pipes are easy to block the bell mouth and coiled inclined pipes, so they must be maintained and scrubbed regularly to ensure that the channels are smooth and free of clogging.
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.
Strengthen equipment maintenance and repair
In terms of equipment, focus on The scrubbing work of each process channel, whether the machine is started or stopped, must be maintained on a regular basis and kept in good condition, so that the quality can be ensured at any time when the machine is started. The quality of equipment operation directly affects the improvement of product quality. During the production process, sometimes due to wear and tear of bearings, gears, etc., quality problems such as detailed yarn dryness may occur. 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.
Strengthen temperature and humidity management
Temperature and humidity control in each process should meet During 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 coarsening, and a weak moisture release process from coarsening 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.
Reasonable setting of winding machine yarn clearing parameters
First of all, It is necessary to give full play to the function of the electronic yarn clearer in the winding process to remove 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, if the yarn clearing parameters are set reasonably, the effect of removing harmful yarn defects will be better and the user’s quality requirements can be better met. 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. We must determine reasonable yarn quality according to fabric requirements, understand the requirements of different fabric structures for yarn defects, and adjust the parameters of the electronic yarn clearer. , to reduce the pressure on the electronic yarn clearer. </p
