Study On Weaving Load Simulation And Loading Performance Of Sizing Yarn

In the weaving process,sizing is subjected to the stretching and friction between the back beam,warp stop,heald and reed,as well as the yarn.Its ability to bear the above weaving load is called the loading performance of sizing.The loading performance of sizing yarn is an important factor to determine whether it can complete weaving successfully.Existing studies usually use the initial(without weaving)breaking strength and hairiness of sizing to evaluate the loading performance of sizing.However,with the effect of weaving load,the performance of sizing is deteriorating,for this change process,it is incomplete to characterize the initial state only by the initial breaking strength and hairiness of sizing.In addition,some studies have used the life times of sizing under the action of friction instruments to evaluate its loading performance.The characterization of this damage state can not effectively describe the state in the sizing bearing process,and the friction load is simulated by the friction block coated with sandpaper,which has the disadvantages of short abrasive life and poor stability of test results.At present,there are many problems in the evaluation methods of sizing performance,such as too simplified simulation,poor stability of test data,and failure to characterize the performance degradation in the process of sizing load-bearing.Under the background of the continuous transformation of China’s textile industry to modern production modes such as intelligent manufacturing and flexible manufacturing,it has important theoretical significance and practical application value to construct a reasonable test method of sizing loading performance,put forward the characterization index of sizing loading performance,and objectively evaluate sizing loading performance for guiding sizing and weaving technology.Therefore,based on the in-depth analysis of the composition of weaving load,this paper makes a reasonable process simulation of weaving load,designs JN-01 sizing weaving load simulation tester,and puts forward a testing method of sizing loading performance simulating weaving load.By analyzing the influence of different instrument parameters on the test results of sizing loading life,the reasonable sample size and instrument parameters are determined.Then,the variation laws of tensile fracture and hairiness index of sizing under separate tensile and friction load are discussed.Finally,the variation laws of sizing tensile performance and fuzzing performance under composite weaving load are modeled and analyzed.The evaluation indexes of sizing strength loss resistance and anti-pilling are put forward,and the sizing loading performance evaluation system composed of a set of testing instrument(JN-01 sizing weaving load simulation tester)and three indexes(residual enhancement rate,hairiness after friction and loading life)is constructed.The research contents and main conclusions of this paper are as follows:(1)According to the tensile and friction load of warp on loom,a sizing weaving load simulation test device is designed,and a sizing loading life test method under simulated weaving state is constructed.The test device consists of tensile load and friction load simulation module,yarn breaking self-stop induction module and human-computer interaction design module.The real-time detection of yarn tension and the appropriate adjustment of let off ensure the simulation of static tensile load;the opening device and the adjustment of opening stroke realize the simulation of dynamic tensile load;the friction rod on the swing reed realizes the simulation of friction load.The yarn breakage self-stop sensing module completes the yarn breakage detection and stop in the test.The realization of yarn dynamic constant tension in the test reduces the test error caused by excessive yarn tension fluctuation.The human-computer interaction design module realizes the parameter setting,automatic control and display and output of test results.Through the test results of 14.6 tex,9.7 tex and 7.3 tex pure cotton sizing samples,the feasibility of the design scheme of the test device and the reliability of the test results are verified.(2)In order to determine the stable test conditions of the tester,the appropriate sample size in the sizing loading life test is studied,the parameter conditions of test instrument are optimized,and the universality of the optimization results of the instrument parameters is verified.In order to obtain effective loading life test results efficiently,through repeated experiments on 14.6 tex and 7.3 tex pure cotton sizing,50 pieces are determined as the appropriate sample size for loading life test by U-test method.Then,taking 14.6 tex pure cotton sizing as the object,the effects of five instrument parameters such as working frequency,opening stroke,yarn tension,reed swing angle and winding speed on the test results of sizing loading life are analyzed by single factor test.The goal is that the test results of sizing loading life are stable and reliable(the minimum CV value of loading life),the test parameters of the instrument are optimized by response surface analysis.The optimization results are selected as the working frequency of 180 rpm,winding speed of 3 mm/min,opening stroke of 32 mm,reed swing angle of 12 ° and yarn tension of 1.7 c N/tex.The deviation between the measured value and the theoretical predicted value of loading life CV is 0.85%,which verifies the reliability of the optimization results.Through the parallel experiments of 9.7 tex and 7.3 tex pure cotton sizing,the highest CV value of loading life is only 25.27%,which verifies the variety adaptability of the optimization results.(3)By applying the tensile load to the sizing yarn alone on the tester,the variation law of the strength and elongation of the sizing yarn under the tensile load alone was studied.Firstly,12 kinds of pure cotton sizes with different sizing rates of 14.6 tex,9.7 tex and 7.3 tex were prepared in the laboratory.Taking the 9.7 tex pure cotton sizing with the sizing ratio of 10.25%as the object,it is found that under the same other conditions,its strength and elongation gradually decrease when the number of tensile load is increased from 200 to 1000.Under the condition of 600 times of tensile load,the effects of opening stroke and yarn tension on sizing breaking strength and breaking elongation are discussed.The results show that with the increase of opening stroke and yarn tension,sizing breaking strength and breaking elongation decrease significantly.(4)The image detection method of yarn hairiness is established by applying friction load to the sizing on the tester and building yarn image acquisition device on the tester,the strength and elongation properties and hairiness of sizing yarn under single friction load were studied.Taking the 9.7 tex pure cotton sizing with the sizing ratio of 10.25% as the object,it is found that under the same other conditions,when the number of times of friction load increases from20 to 100,its strength and elongation gradually decreases and the hairiness gradually increases.The effects of yarn tension and reed swing angle on sizing breaking strength,breaking elongation and hairiness are discussed when the number of friction load is 60 times.The results show that friction load alone has a more significant effect on sizing hairiness,but has a weak effect on sizing breaking strength and elongation.(5)By constructing the sizing loading performance evaluation system,the effective characterization of sizing strength loss resistance and anti-pilling under weaving load is realized.Taking 14.6 tex pure cotton sizing with different sizing rates as the object,the changes of breaking strength,breaking elongation and hairiness were studied when the number of weaving load increased in the range of 20 – 100.The relationship between breaking strength and load times,breaking elongation and load times is linear;there is a logarithmic relationship between hairiness and load times.According to the fitting model,the evaluation index of strength loss resistance of sizing —— residual enhancement rate and the evaluation index of anti-pilling of sizing —— hairiness after friction are extracted.On this basis,the effectiveness of the evaluation index is verified by using pure cotton sizing with different sizing rates of 9.7 tex and7.3 tex.Finally,by testing the evaluation indexes of sizing samples in actual production and analyzing the relationship between the indexes and weaving effect,it is verified that the three indexes proposed in this paper,such as residual enhancement rate,hairiness after friction and loading life,can effectively characterize the performance of sizing under weaving load and better reflect the actual situation of weaving production.The sizing weaving load simulation tester developed in this paper can effectively simulate the weaving process,explore the relationship between sizing loading performance and weaving load,and finally construct the evaluation system of sizing loading performance,which has important reference value for formulating sizing technology and weaving technology.