| With the improvement of people’s living standards and increased demand for dressing aspects,manufacturers of denim fabrics are no longer limited to traditional raw materials for the production of stretch denim fabrics and have started to use new types of elastic fibres to spin new types of stretch yarns to make fabrics more comfortable and beautiful,and have also started to seek new production methods to reduce the environmental pollution and waste of resources caused by the process,focusing on low carbon green in the production of textile and clothing.This thesis is about the development of a new way of producing stretch yarns using stretch fibres.In this thesis,several new double core stretch yarns are developed using elastane fibres and used as weft yarns to overcome the shortcomings of traditional stretch yarns.The warp sizing process for warp yarns is explored and applied to the preparation of warp yarns for stretch denim fabrics,which can reduce the environmental pollution caused by sizing and obtain denim fabrics with excellent performance after weaving.By analysing and summarising the available elastic fibres and elastic yarns in the market,four types of fibres-T400,PTT,PET and spandex-were selected as core yarns,with cotton as the outer covering fibre,and four types of elastic core yarns with a thread density of 49.2tex were spun using the cyclo-spinning method..The performance of the four yarns was tested and analysed,and it was found that the double core elastic yarn had superior performance compared to the traditional single spandex yarn.By changing the ratio of the two sizing materials and optimising the sizing process,the performance of the sizing solution and the sizing yarn were tested and analysed,and the most suitable sizing ratio and sizing process without desizing were determined.The optimum sizing ratio and rejection-free sizing process were determined,which can achieve good sizing performance with low sizing rate and low temperature sizing.Finally,the four elastic yarns were used as weft yarns and the warp yarns were sized using the no-desizing process to weave five fabrics.The fabrics produced by the no-desizing process have better strength and softness than those produced by conventional sizing,and the fabrics produced by the no-desizing process do not need to be desized,reducing waste water and energy losses.The no-desizing double core stretch yarn denim fabric developed in this thesis can compensate to a certain extent for the defects of traditional cotton covered spandex denim fabric,and also reduce the pollution problems caused by the production process of traditional denim fabric,and also provide better taking performance and make the denim fabric more soft and comfortable,this low carbon and green production method not only protects the environment and reduces pollution,but also improves the product quality. |
