High-Frequency Test And Evaluation For Dynamic Tension Of Warp Knitting Yarn

Yarn tension has always been an important research topic in textile field, and sustained attention in the direction of woven, spinning and knitting. The control of yarn tension has a direct impact on the improvement of production efficiency and product quality control. In the field of warp knitting, the yarn tension of a late start. However, the increasing speed of warp knitting machine, product quality requirements and the market demand for knitting staple products, put forward higher requirements on the more accurate dynamic warp yarn tension control. To explore high-precision tension test method and comprehensive science evaluation method is an important basis for further in-depth study of warp yarn tension and precise control. This paper carried out a series of research, which provides a reference for the test and analysis method of warp yarn tension of choice, has certain theoretical significance and practical value.First of all, this paper explored the stable high frequency test method of dynamic warp yarn tension, based on the demand and characteristics of warp yarn tension test method of high frequency. With the scientific selection of hardware and software settings, a stable tension test system was built, and the experimental conditions of test procedures and control were reasonable arranged and standardized, and through the tension stability test, the high reliable warp yarn dynamic tension test was realized.Secondly, the paper discussed the determination of the analysis method of warp yarn tension and the selection of main influence factors, combined with the features of measured tension curves and the tension theory calculation results. According to the result of high frequency test, the characteristic of tension curve is analyzed. And the difference between instantaneous yarn demand and yarn feed was calculated to analyze the factors of warp yarn dynamic tension fluctuation. According to the analysis results of characteristic of tension curve and theoretical, it provided a reference for determining the warp yarn tension analysis method and put forward reasonable suggestions for the selection of main influence factors.Then, based on the dynamic characteristics of warp yarn tension, the paper put forward specific methods to make comprehensive evaluation from three aspects, the overall level of tension, tension fluctuation and the change degree of wave crest region. It Scientifically calculated the discrete variables to evaluate the magnitude of tension, used statistical methods to analyze the overall distribution characteristics of tension, reasonably selected function curve for fitting analysis of sudden changes in peak area, found suitable index and put forward the more scientific and comprehensive evaluation method.Finally, the rationality of the test and evaluation of warp yarn tension map of the proposed method is verified by experiment. In the model of KS4-EL on tricot knitting machine, three factors were selected for experiment, according to the above test methods, and the comprehensive evaluation including the overall level of tension, tension fluctuation and the change degree of wave crest region was analyzed The scientific nature and practicality of the test method and evaluation method are verified.