Study On The Relationship Between The Processing Parameters And The Properties Of The Cotton/Polyurethane Elastic Yarn And Elastic Fabric

Polyurethane filament fiber is a high flexibility of synthetic fiber which has got rapid development in recent years.It is a good extension and elastic recovery fiber.Elastic yarn was widely used in skin-tight underwear,shirts,sportswear,jeans and casual wear.The elastic fabric has a broad market prospects. Many researchers have been involved in the study on the factors influencing the properties of elastic fabric.In the thesis the relationship between the processing parameters and the properties of cotton/polyurethane elastic yarn and elastic fabric are investigated in order to give a reference to the production or the theoretical research.First,the 39tex and 61tex rotor spun yarn and ring spun yarn with different draft ratios of polyurethane filament have been spun.The effect of the draft ratio of polyurethane filament on the properties of rotor spun yarn and ring spun yarn is investigated.The results indicate that the relationship between the properties of elastic rotor spun yarn and the draft ratio of polyurethane filament is similar with that of elastic ring spun yarn.With the increase of the draft ratio of polyurethane filament,the strength of elastic yarn increases;the elongation of elastic yarn and elastic recovery increase first and then goes down;the evenness and hairiness of elastic yarn keep increasing. There are also some differences between elastic rotor spun yarn and elastic ring spun yarn.The strength,evenness and hairiness of elastic rotor spun yarn are lower than those of elastic ring spun yarn,while the elongation and elastic recovery are higher than that of elastic ring spun yarn.It can be seen from the scanning electron microscopy that the structure of elastic rotor spun yarn is that the staple yarn wraps around the filament, while the structure of elastic ring spun yarn is that cotton fiber covers the filament.Secondly,some kinds of elastic fabric made of ring spun elastic yarn have been woven with the pilot rapier loom.The effect of the draft ratio of polyurethane filament,weave pattern and fabric density on the properties of elastic fabric are investigated.The optimum parameters are obtained using the orthogonal design theory.For the elastic fabric made from 39tex ring spun yarn,the optimum parameters are:the draft ratio 3.63, weave pattern 3/1 twill and fabric density 240/200.Thirdly,the different effects of draft ratio of polyurethane filament on the properties of elastic fabric made from rotor spun yarn and ring spun yarn are compared.The optimum parameters of elastic fabric made from 39tex rotor spun yarn are obtained: the draft ratio of polyurethane filament 4.00,weave pattern 3/1 twill and fabric density 240/200.In addition,the properties of the rotor elastic fabric,the ring elastic fabric and the pure cotton ring spun fabric are compared.The results indicate that the relationship between the properties of rotor elastic fabric and the draft ratio of polyurethane filament is similar with that of ring elastic fabric.With the increase of draft ratio of polyurethane filament,the breaking strength of fabric keeps increasing;the breaking elongation,elastic recovery and crease recovery increase first and then go down.The variation of the permeability is insignificant.Under comparable conditions,the breaking strength of cotton fabric is greater than that of the elastic fabric,while the breaking elongation,elastic recovery, crease recovery and permeability of the pure cotton fabric are lower than that of the elastic fabric.The breaking strength of the rotor elastic fabric is less than that of the ring elastic fabric, while the breaking elongation is greater than that of the ring elastic fabric and the elastic recovery,crease recovery and permeability are better than that of the ring elastic fabric.Fourthly,the relationship between the property of the elastic fabric and the draft ratio of polyurethane filament is predicted using adaptive neural-network-based fuzzy inference system (ANFIS).The prediction results agree well with the experimental data.With the increase of the draft ratio of polyurethane filament,the breaking strength of fabric keeps increasing,while the breaking elongation,elastic recovery and crease recovery increase first and then go down.The variation of the fabric permeability is insignificant.