| As people have higher and higher requirements for fabric performance,spinning technology is increasingly diversified,and the composite spinning method of two or more raw materials has gradually become a hot spot.As a major branch of compound spinning,covered yarn has developed rapidly.At present,the covered spinning mainly adopts the hollow spindle covering spinning method and the air covering,in which the hollow spindle coating method can spin a variety of combined yarns,which has a wide range of trial spinning raw materials,high yarn strength,and good hairiness.At the same time has the advantage of good bulkiness.With the development of new yarns,the raw material combination of covering yarns is becoming more and more abundant.These yarns can merge the advantages of outer covering yarn and inner core yarn.Spandex has excellent elastic properties and is often used as the inner core of covering yarn.Giving spandex-covered yarn excellent elasticity.The use of high-strength yarn to improve the mechanical properties of the covered yarn plays a very important role in subsequent weaving.This article aims to develop a covering yarn for bandage fabrics whose mechanical properties and elastic properties meet the requirements.Because the body can withstand different tensions at different ages and different parts,the performance of bandage should be different.By discussing the influence of the spinning process on the performance of the covered yarn,and the relationship between the level of weaving process and the performance of the bandage fabric,it can quickly meet the needs of different elastic bandages,match its optimal process of production,and achieve the best results,while taking into account the other properties of bandage.The main contents of research and results of this article are as follows.(1)Use the spandex and nylon filaments provided by the enterprise for covering spinning.The 40/70 spandex / nylon covered yarn,40 D spandex filament and 70 D nylon filament were tested respectively for their strength,elasticity and shrinkage in boiling water.Comparative analysis shows that the spandex / nylon covered yarn has greater breaking strength and elongation than nylon filaments,and its elastic properties have obvious advantages compared with spandex filaments.The boiling water shrinkage performance is significantly improved compared to the spandex.(2)Combine the design of 3 fineness of spandex and 3 fineness of nylon provided by the enterprise,the fixed design twist is 780 twists / m,the spandex pre-draw ratio is set to 2.6,and on the covering machine,test spinning 9 kinds of covered yarns with different configurations of filament.In order to explore the difference between the designing twist and the actual twist,to ensure the accuracy of the machine,the test analyzed the actual twist.The results show that the actual twist is slightly larger than the design twist due to the changes in the yarn package and the working environment of the machine.The difference between the twist and the actual twist is small,and the error can be ignored.(3)The test compares the breaking strength,elongation at break,elastic deformation and elastic recovery rate of the above 9 kinds of covered yarns.Considering the yarn coating situation and the application scenarios required by the enterprise,preliminary determination of three different thickness configurations of the coating combination,spandex and nylon are respectively 20/40,40/70,70/100 configuration,to determine the yarn for subsequent process Line configuration.(4)According to the coating degree formula,determine the five levels of nylon coating twist,and the corresponding pre-drawing multiple levels according to the spandex fineness.A single-factor controlled variable test was used to coat and spun the three filament configurations,and the effects of twist and pre-draw ratio on yarn breaking strength,elongation at break,elastic elongation,and elastic recovery were explored.According to the results of the single factor test,the optimal pre-draw ratio and twist are selected at three levels,and the orthogonal test is used to optimize the coating process parameters.Combined with range analysis and analysis of variance,we explored the significant influence of nylon coating twist and pre-draw ratio on yarn performance.Using the comprehensive scoring method,the best process parameters of the spandex / nylon covered yarn in 20/40 configuration are: cover twist of 1000 twists / m and pre-draft multiple of 3.4.Spandex / nylon covered yarn in 40/70 configuration The best process parameters are: the coating twist is 800 twists / m,and the pre-draw ratio is 3.2.The best process parameters for the 70/100 configuration spandex / nylon covered yarn are: the coating twist is 600 and the pre-draw ratio is 3.4.(5)In order to meet the requirements for the production of bandage fabrics,three configurations of spandex / nylon covered yarn were used to test weave plain weave elastic woven fabrics.The basic specifications of the bandage fabrics and the tensile fracture properties and elastic elongation of the fabric were tested.And elastic recovery performance.The results show that the 20/40 configuration yarn is used for the weaving of light and thin bandage fabrics.The thickness is thinner and the strength is lower.After the constant elongation and constant load stretching,the elastic recovery reaches more than 93%.The elastic elongation under load is low,which meets the basic requirements of thin and light bandages.Weaving medium-thick bandages with 40/70,the elastic recovery performance reaches more than 96%,and the elastic elongation and break elongation are moderate.With a tensile tension of 300 cN,the elastic recovery can reach 98% and the elastic elongation is 23.6%.For thick bandages,the fabric used requires greater strength,and higher elastic recovery and elastic elongation requirements.It is configured with 70/100 to meet the strength and thickness requirements,and after a large draft,or add a large load,elasticity the recovery performance is stable above 95%. |
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