The use of spandex stretch yarn has enabled the denim variety to develop into a new field. It can make denim clothes fit and comfortable. It can be matched with bamboo or different colors. Make denim products more suitable for fashionable and personalized consumer needs. So there is great potential for development. The elastic elongation is generally 20% to 40%. The size of the elastic stretch depends on the weave design of the fabric. The tighter the warp and weft organization on the cloth machine, the greater the elasticity. On the contrary, under the condition of fixed tightness of warp yarn structure. The greater the tightness of the weft elastic yarn, the smaller the elasticity. The zonal tightness reaches a certain level, and even loss of elasticity occurs.
In addition, the outstanding problem of the finished elastic denim fabric is that the shrinkage rate in the weft direction is generally over 10%. Individually even as high as 20% or more. The instability of the cloth width brings great difficulties to the production of clothing. The first solution is not to make the elastic elongation too large during product design, generally 20% to 30%. That is to maintain a certain degree of tightness in the warp and weft direction, and adopt a method of appropriately increasing the tension when pre-shrinking. The fabric has a greater shrinkage, so as to obtain a lower residual shrinkage rate in the weft direction of the finished fabric. Another solution is to heat-set the stretch denim after pre-shrinking. In this way, a more uniform cloth width and a more stable, lower weft shrinkage rate can be obtained. Meet the requirements of garment processing and production.