Study On Dynamic Tension Characteristics And Compensation Technology Of Warp-knitted Yarn

Stable yarn weaving tension has always been a research hotspot in the textile industry.The level and fluctuation of tension will directly affect the quality of finished products.In warp knitting production,the control of yarn tension usually depends on the experience of the technologist.In terms of theoretical research,there are relatively few studies on warp knitting yarn tension compensation.There is no systematic summary and arrangement of factors affecting yarn tension compensation,and the influence of various factors on tension compensation and the degree of demand are less involved.In this paper,a series of studies are carried out to test and analyze the yarn tension under different process parameters and machine parameters,to discuss their influence rules on yarn tension and yarn tension compensation,and to put forward the scheme of active tension compensation of warp knitting machine,which lays a theoretical foundation for the accurate control of yarn tension.Firstly,this paper expounds the compensation principle of the tension compensation device,lists the specifications of the tension components of the common high-speed warp knitting machine,and introduces the testing methods of the tension of warp knitting yarn and the stiffness of the tension compensation device.In order to analyze the influence of various factors on yarn tension,this paper evaluates the tension curve of single-period yarn,the overall weaving level of yarn tension,the distribution of yarn tension and the overall fluctuation of yarn tension.Based on the yarn tension,this paper explores the influence of the stiffness of the compensation device on the yarn tension compensation,introduces the yarn tension compensation coefficient on the basis of the evaluation of the yarn tension index,and evaluates the compensation performance of the tension compensation device under different stiffness from the tension compensation of single-period yarn and multi-period yarn.Secondly,combined with practical experience and warp knitting situation,the influence of the change of machine speed,let-off quantity,structure and raw material on the yarn tension is analyzed.The test results are analyzed and compared with the evaluation index,and the influence rule of machine speed,yarn delivery quantity,structure and raw material on the yarn tension is summarized.Thirdly,the change of yarn tension waveform is analyzed in combination with the change of stiffness of the compensation device,and the reason for the change of yarn tension is explained by the difference between the amount of yarn feeding and the amount of yarn consumption.In addition,combining with the evaluation index of yarn tension compensation,the influence of the stiffness of the compensation device and the change of the installation Angle of the compensation device on the yarn tension compensation is discussed.Finally,on the one hand,through summarizing the influence law of various factors on the yarn tension,and multiple regression analysis method was used to study the compensation device rigidity,machine speed,organization,the relationship between the quantity of yarn and yarn diameter,on the other hand,the influential factors of the yarn tension compensation to establish multivariate regression equation,analysis the influence factors on the yarn tension compensation of primary and secondary relations,set up about the compensation device stiffness coefficient of average,yarn tension compensation and compensation responsiveness of regression equation,and combining the practice and multivariate regression equation of the theory of the yarn tension and optimization scheme is given.