With the continuous improvement of yarn quality requirements by customers, spinning companies pay more attention to the quality of yarns. At present, the harmful defects affecting the quality of the cloth mainly include thick sections, details, unevenness of the strips, flying flowers, neps and abnormal defects. By standardizing production operations and focusing on equipment maintenance, process adjustment and quality control, spinning companies can control the yarn defect within the normal range.
1. Reasonable configuration of process parameters to reduce spinning yarn defects
Reducing the semi-finished yarn defect of the woven fabric can effectively reduce the breakage rate of the spun yarn, and reducing the yarn breakage rate can increase the output, reduce the cost of the ton yarn, stabilize the yarn quality, and create favorable conditions for improving the competitiveness of the enterprise. We have summarized a few specific practices.
In the combing process, the optimal configuration and management of the combing and combing components can be achieved, and a better combing effect can be obtained. By actively and effectively selecting the corresponding technical measures, the intarsia of the top comb and the cylinder can be minimized. Phenomenon, to avoid the fiber into the cotton mesh in a bundle structure, reducing the probability of breakage in the next process. Regularly check the tension state and wear condition of the drafted toothed belt and the looped toothed belt, and adjust the tension of the looped strip reasonably, which can reduce the probability of the slatted overhead breakage while reducing the congestion of the coiler.
It is beneficial to reduce the dry CV value of the spun yarn by appropriately reducing the jaw spacing of the roving, the center distance of the roller, and the drawing ratio of the rear zone. However, the tightening of the above process will inevitably increase the drafting force of the sliver and the control force of the floating fiber. The gripping force and the drafting force, the guiding force and the control force must be developed in synchronization to normal drafting to prevent the roving process from being poor. Poor drafting caused by defects in the drafting element and the pressurizing mechanism. Therefore, the nipper's jaw spacing, roller center distance, rear zone draw ratio, and total draft multiple are sought to find an optimal combination.
At the same time, it is necessary to strengthen the operation management work, reduce the influence of the machine's unclean fly-flowers attached to the yarn, the winding mechanism on the bad effect of the yarn, and if these defects are serious, the spun yarn may be sporadic.
2, improve and control the quality of semi-finished products
In the drawing process, after the combing process is combed, the fiber separation degree, parallelism and straightness are good, but the cohesion between the fibers is poor, easy to loose and hairy, and the fiber will not be in the subsequent process. There is a chance to sort out. Therefore, the rough process should reduce the deterioration of the internal structure of the sliver by the drafting effect before the twisting of the strand, reduce the factors causing the edge fiber defect, reduce the short pile, the fly flower attached to the sliver, and reduce the unwinding of the sliver. Rubbing, twisting, entanglement, and twisting around the time, thereby reducing the neps formed by friction, snagging, entanglement, and twisting.
Reducing the draw ratio and drafting force can reduce the growth rate of the linters and neps, thereby improving the strip;
According to the quantitative determination of the sliver, the selection of the smaller thick bell mouth diameter can improve the tightness of the sliver and reduce the probability of partial sliver when the sliver is fed after the roving frame, thereby improving the strip and hairiness;
According to the quantitative calculation of the sliver and the capacity of the barrel, a reasonable length is designed to avoid the excessively large sliver capacity, causing excessive compression between the top sliver and the loop bobbin to increase friction, twisting and twisting to form a neps;
It is necessary to control the weight deviation of the cooked strips, reduce the dry CV value of the cooked strips, and prevent the fine yarn length details caused by the bad factors of the drawing process.
Therefore, the drawing process should reduce the dry CV value of the cooked strip under the premise of eliminating the long details. These are mainly achieved by rationally designing the process route, configuring the drafting element and the pressurizing mechanism, and strengthening the operation management and the cleaning and cleaning of the machine.
In the roving process, the dry roving CV value and the structure of the sliver fiber affect the yarn dry CV value and the frequent yarn defect. The roving quality CV value affects the spun yarn quality CV value, and the roving yarn crepe affects the spun yarn sporadic yarn defect.
3, adjust the moisture regain rate of the low-gross blended yarn 疵
Our company reflected the problem of high yarn defect and broken head of R/C65/3542tex yarn for the user. Through the inverted bobbin and analysis of the hundred yarn gauze, the cause of the above problems was found out. Through a series of measures, the yarn quality has reached the user's requirements.
By analyzing a batch of yarns, it was found that the yarn count in the pre-spinning process was 56%. According to the investigation, the re-moisture rate of the semi-finished yarns of this batch of yarns is relatively small, and the standard moisture regain rate after mixing the slivers is 11.4%, but the actual moisture regain rate is only 7.5% to 7.8%. We take viscose fiber pretreatment, disc humidification, and carding process to moisturize and so on, so that the regain rate of the card is 9.5%. The production area of the drawing process is also humidified accordingly, and a carbon black rubber roller is used to prevent the rubber roller from being sucked and entangled. After the cotton tampon is mixed, the actual moisture regain rate reaches 8.5% or more. By humidifying, the spinning production is significantly improved and the yarn defect is also significantly reduced.
The spinning speed of the spun yarn of the coarse yarn is high. It is advisable to adopt a large gauge and heavy pressurization process, and adopt a reasonable pressure position to ensure that the drafting force is compatible with the gripping force and also reduces the rubber roller. Damage caused by the apron.
Because it is a thick yarn, if the joint parameters are improperly adjusted during the splicing process, it will form a defect and appear on the cloth surface. Therefore, in the splicing process, parameters such as blown yarn tail, yarn end stacking, jet splicing, and winding speed are preferred. By adjusting the splicer and the splicing chamber, the speed of the drum is reduced to 1200 m/min. The main yarn clearing process parameters are short and thick +130%×1 cm, long and thick +30%×15 cm, and the length is -40%×20. In centimeters, the reversal of 100,000 meters of yarn defects reached about four.
Through the implementation of the above measures, the production of the yarn of this variety is stable, and the 100-tube yarn defect has been significantly improved, which has been recognized by users.
