Study On Processing Technology And Properties Of Cotton-modal Knitted Fabric With TPU Melt-spinning Spandex

Spandex is also called as polyurethane elastic fiber,it has excellent properties such as high elongation and good elastic recovery.There are many kinds of spinning methods for spandex,Dry spinning is the most widely used method to product polyurethane elastic fiber.In this case,BASF Polyurethane(China)Co.,Ltd.and some other international chemical manufacturer develop a melt-spun spandex yarn.Compared with the spandex yarn produced by the traditional spinning method,the melt-spun spandex has more simple product process,lower raw material cost,higher develop efficiency and environmental protection.It has become an well popular spinning method in recent years,and has good market prospects.At the same time,due to the slightly different performance from the traditional dry-spun spandex,the melt-spun spandex yarn will have many changes in the knitting and finishing process.This paper mainly studies the properties of the new melt-spun spandex yarn made of TPU particles produced by BASF,and the processing technology and fabric properties of cotton-modal knitted fabric containing TPU melt-spun spandex.Firstly,compare the properties of the melt-spun spandex and the low-temperature dry spandex yarn,including the difference in the fracture strength,elastic recovery rate and initial modulus of the two materials under different heat setting temperatures and different heat setting time conditions.The results show that the fracture strength and elastic recovery rate of the melt-spun spandex bare filament are better than that of the low-temperature dry-spinning bare filament under untreated condition.After the heat setting treatment,the fracture strength of the melt-spun spandex yarn is decreased,and the elastic recovery rate is improved.Secondly,Study on the knitting process of TPU melt-spun spandex/cotton-modal knittedfabric.Make clear the best feeding tension range of spandex.Studies have shown that when22.2dtex melt-spun spandex is knitted with 14.6tex cotton-modal yarn,if the tension of cotton-modal yarn is controlled at the normal level,the tension of the spandex yarn can be setted between 2.8cN and 5.6cN,when 33.3dtex melt-spun spandex is knitted with 14.6tex cotton-modal yarn.,the tension should be controlled between 3.2cN and 5.0cN.When the fabric structure and the bending depth are constant,the smaller the tension of the spandex yarn,the larger the spandex content of the fabric the larger the length of the spandex knitted loop,the larger the width of the fabric,the smaller the tension of the spandex yarn,the smaller the thickness of the fabric,and the smaller the fabric density.Then,discussed the heat setting process of TPU melt-spun spandex/cotton-modal,mainly concentrate on pre-heat setting process.By using single factor and orthogonal experimental methods,find the best heating process of TPU melt-spun spandex/cotton-modal fabric by evaluating the tensile resilience,dimensional stability and crimping of fabrics.The research shows that the best heat setting process of TPU melt-spun spandex/cotton-modal fabric is temperature of190?,the heating time is 60 s,and the expansion rate is 6%.Finally,make some reasearch on the effects of heat setting process conditions on fabric curling and anti-dissociation propertie.The fatigue properties of TPU melt-spun spandex/cotton-modal knitted fabrics were studied.In summary,some properties of the melt-spun spandex bare silk product have been superior to the low-temperature dry-spinning spandex,but the melt-spun spandex knitted fabric sample has advantages and disadvantages compared with the low-temperature dry-spinning spandex fabric,and the fabric has anti-dissociation performance and Fatigue resistance still needs improvement.