Polyester yarn

How to control spinning fine defects with testing instruments

How to control spinning fine defects with testing instruments

With the extensive application of modern digital control technology in textile machinery, textile accessories and textile test instruments, as well as the improvement of stability, consistency and long-term performance of textile accessories and textile special parts, frequent yarn defects are almost completely controlled. However, due to the variability of spinning raw materials, the uncontrollability of carding technology, the discontinuity of clean management and the large number of floating fibers Process variability and occasional defects become difficult to control and reduce, which will be the key to the improvement of spinning technology and the improvement and development of standard formulation in the future.

Single fiber tester is the basis of controlling fine yarn defects

At present, the fast testing instrument for cotton physical index and blended cotton quality index is the large capacity cotton fiber tester. Few spinning manufacturers use single fiber tester to test the physical index of cotton. Because the cotton fiber itself contains a large number of unopened fiber bundles, cords, hard impurities, cottonseed shell, large stiff pieces and large sterile seeds, the cotton fiber is in a state of hardening, which needs to be opened before forming a fiber bundle state.

The key to control the fine yarn defect is to check the quality of carding sliver with single fiber tester

The spinning practice shows that 90% of the carding sliver quality has been determined after the carding sliver quality is formed in the carding process, and the fine yarn defects of the carding yarn are basically determined; as for the combed cotton yarn, the basic determination of the quality of the combed cotton yarn is determined by the carding sliver quality and combing sliver quality.

The quality of combing sliver is the main factor to determine the quality of combed yarn. The fine yarn defects of combed yarn are determined by the number of harmful defects in the combed sliver. Because there are many carding machines and combers in spinning factory, and carding machine and comber are the key process of spinning quality control, the testing speed, testing cycle and testing quantity of carding sliver quality and combing sliver quality are directly related to the quality of carding sliver and combing sliver.

Due to the slow speed of conventional visual inspection methods, the number of tests is affected by human factors, light factors and combing quality factors, so the comparison of test data is poor. Therefore, establishing the quality control standard of carding sliver and combing sliver is the key to control the fine yarn defects of cotton yarn. Table 1 shows the quality standards of semi-finished products of Uster at different levels.

Development and application of multi functions of sliver tester

In many spinning mills, there are not only no large capacity cotton fiber tester and single fiber tester, but also no 100000 meter yarn defect tester. Through a long-term tracking of some domestic spinning mills, it is found that only 10% of the spinning factories have these instruments. The quality control of many spinning factories is almost based on several simple indexes of cotton yarn evenness, details, slubs and neps, and the technicians and managers of these spinning factories don't know what the harmful fine yarn defects are. Although there is only a simple yarn evenness tester, there are several changes of the quality indicators in details, slubs and neps. These - 30%, - 40% details, + 35% slubs and + 140% neps all reflect the existence of a large number of fine yarn defects. The analysis and control of these test quality indexes play an important role in controlling fine yarn defects.

The use of 100000 m yarn defect tester is the key to formulate the fine yarn defect control standard

The most commonly used testing instruments in textile mills are evenness tester, some conventional weight tester and twist tester. The quality management personnel mistakenly believe that single fiber tester and 100000 m yarn defect tester are not important for cotton yarn test, and the control indexes of test are too far from the conventional eye detection and blackboard sliver defect detection, which can not establish an effective corresponding relationship Quantity and quality control of cotton yarn will not help.

This paper summarizes the rules and causes of fine yarn defects in the related process of 100000 m yarn defect meter, establishes the fine yarn defect control standards of different varieties and different quality requirements, so as to effectively guarantee the quality of cotton yarn and fabric. By controlling the fine yarn defects A0, A1, A2, B0, B1, B2, C0, C1, H0, H1, other harmful physical indexes of cotton yarn are controlled, and the control standard and range of cotton, blended cotton, carding sliver, NEP of combed sliver, seed chips with fiber, impurities, short fiber rate and percentage content of immature fiber are established. Therefore, in the process of cotton yarn quality management, managers and technicians of spinning factory should realize that paying attention to the test of 100000 m yarn defect meter is to pay attention to the quality control of the whole process. In modern spinning process, the statistics and shearing control of cotton yarn defects by automatic winder is an effective way to eliminate all kinds of harmful cotton yarn defects. Under the condition that the electronic yarn cleaning parameters of the automatic winder remain unchanged, the more shearing times, the more fine yarn defects in the tube yarn. Therefore, the test results of 100000 m yarn defects are compared with the cleaning effect of automatic winder, so as to strengthen the removal of defects in the previous process and harmful fibers, and ensure the quality statistics and 100000 m yarn defect test after yarn cleaning data on the automatic winder It is the key control method to ensure the cotton yarn fine yarn defect standard to adapt to the data quality statistics.

Our current quality control of polyester yarn in addition to detection means, in fact, in the production process control is also very important.