Research On Twisted Layered Yarn Based On Ring Spinning Core-spun Technology

Ring spinning technology has always occupied a dominant position in spinning production due to its plenty of advantages,but there are few studies on spinning layered structure yarns with different inner and outer twists on ring spinning frames.In this paper,cotton fiber is used as the raw material,and the forming mechanism of core-spun yarn is used to spin the layered structure yarn with different inner and outer twists on the ring spinning frame;Exploring the variation law of the twist factor of the core yarn in the layered structure yarn after the core-spun process;Analyzing the influence of core yarn twist factor,core-spun twist factor and core/sheath ratio on the performance of layered structure yarn;Developing soft products according to the law of twist change,and providing ideas and theoretical basis for the development of yarns with moisture-transmitting properties.The specific research content is as follows:First,designing and trying spinning layered yarns with different inner and outer twists on the ring spinning machine.The results show that it is feasible to use the core-spun yarn formation mechanism to spin layered yarns with different inner and outer twists on the ring spinning frame.Observing the transverse and longitudinal cross-sections of the yarn through scanning electron microscopy.It is found that the inner and outer layers have a large difference in twists,and the core and sheath layered structure is obvious.According to the different twist directions of the core yarn,the layered structure yarn can be divided into ZZ and SZ layered structure yarns:the core yarn of the ZZ layered structure yarn is Z twist direction,the core yarn is also Z twist direction,and the core yarn will have additional twist after the core-spun process,thus forming a layered structure yarn that is tight inside and loose outside;the core yarn in the SZ layered structure yarn is S twist direction,but the core yarn is Z twist direction,and the core yarn will reduce the twist after the core-spun process,thus forming a layered structure yarn with tight outside and loose inside.The second is to explore the changing law of the core yarn twist factor in the ZZ layered structure yarn during the core-spun process.The results show that the twist factor of the core yarn in the ZZ layered structure yarn,after the core-spun process,is related to the initial twist factor of the core yarn and the core/sheath ratio.The larger the initial twist factor of the core yarn,the larger the twist factor of the core yarn after the core-spun process.But when the twist factor increases to a critical value of 320,it is difficult for the core yarn to add twists,and the range of twist factor changes decreases.In addition,the larger the proportion of the core yarn,the easier to add twist,and the greater the twist factor of the core yarn after the core-spun process.When the linear density of the ZZ layered structure yarn is 58.3tex and the core-spun twist factor is 300,the core yarn twist factor(y),after the core-spun process,changes with the core yarn initial twist factor(x₁,ranging from 230 to 350)and the proportion of core yarn(x₂,ranging from 0.15 to 0.25).And the regression equation is:=243.58-0.001₁~2+290₂,and confirms the correctness of the regression equation through experiments.Then analyzing the influence of core yarn twist factor,core-spun twist factor and core/sheath ratio on the performance of ZZ layered structure yarn,developing yarns with both strength and softness based on the best process parameters.The results show that with the increase of the core yarn twist factor,the breaking strength of the yarn improves first and then deteriorates,the evenness deteriorates slightly,the number of hairiness of 3mm and above has little change and the diameter change of the yarn is also small;As the core-spun twist factor increases,the yarn breaking strength,evenness and other indicators are improved,the yarn diameter decreases.At the same time,the core-spun twist factor has a significant effect on the softness of the yarn,low twist can achieve a soft hand feeling;As the proportion of core yarn increases,the breaking strength of the yarn increases,but the evenness becomes worse,the number of hairiness of 3mm and above decreases,the diameter decreases.The best process parameters are obtained through orthogonal experiment:core yarn twist factor is 290,core spun twist factor is 230,and core/sheath ratio is 15/85.And the optimized ZZ layered structure yarn has a higher breaking strength than the conventional ring spun yarns with the same linear density(58.3tex)and twist factor is 230,and the softness is significantly better than the conventional ring spun yarn with the same linear density(58.3tex)and twist factor is 360.Finally,exploring the change rule of core yarn twist factor in SZ layered structure yarn,after core-spun process,and the performance of SZ layered structure yarn.The results show that when the linear density of the layered structure yarn is 72.9tex and the core-spun twist factor is 550,the regression equation of the core yarn twist factor(y),after the core-spun process,changes with the core yarn initial twist factor(x₁,ranging from 180 to 220)and the proportion of core yarn(x₂,ranging from 0.10 to 0.20)is:=0.57₁-960₂+83.6,and confirms the correctness of the regression equation through experiments.At the same time,the test found that the wicking height of the SZ layered structure yarn is higher than the conventional ring spun yarn with the same linear density(72.9tex)and the twist factor is 360,so the moisture permeability of SZ layered structure yarn is better than the conventional ring spun yarn,which can provide new ideas for the development of moisture-permeable and quick-drying fabrics.