The Application Of Wool/Spandex Core-Spun Yarn On Woolen Spinning System And The Study Of Structure And Property Of The Yarn

ABSTRACTThe spandex core-spinning method has been successfully applied on cotton and worst spinning system. However there is no such report on woolen spinning system. Wool/spandex core-spun yarn produced on woolen spinning frame may achieve the following advantages: finer and better quality yarn with the same raw material; shortening process and cutting the cost; endowing with novel character and enriching the category of yarn. In this paper, mechanical properties of woolen products were studied theoretically and practically in detail. A new type of accurate theoretical model was established to predict tensile properties of wool/spandex core-spun yarn, which enriched the theoretical study of mechanical property of yarn and was helpful in theoretical analysis of fabric properties. The design and development of woolen elastic fabric provided reference for mass production in mill, which had proved to be economic and applicable. Practical elastic elongation of fabric was predicted and turned out to be good to manufacturing in mill. Correction equations were derived to describe tensile and recovery properties of stretch woolen fabric, which provided a new way in analysis of elastic products.In theoretical analysis on tensile properties of elastic core-spun yarn, a new parameter, fiber utilization coefficient, was provided by combining with fiber slippage theory. Theoretical model was set up based on classical theory of yarn mechanical properties. Through the study, theoretical relations between core-spun yarn tensile properties and fiber parameters, yarn parameters, yarn structure were established. Also the impacts of fiber utilization coefficient and yarn twist on yarn properties were discussed theoretically. Comparison with experimental results showed that theoretical model was accurate and applicable. In the practical prediction of fabric elastic elongation, theoretical finished fabric width was derived. Combined with the effect of each process on fabric properties, fabric elastic elongation was obtained. Furthermore, theoretical prediction on tensile and recovery property of elastic fabric was studied on the basis of former fabric theory. Correction equations were worked out to establish the relation between fabric tensile properties and fabric structural parameters, tensile and compression properties of warp and elastic weft.In experimental part, woolen spinning frame was modified to adapt to produce good quality elastic core-spun yarn. Single factor and orthogonal experiments were carried out to discuss the impact of spandex percentage, yarn twist factor, spandex drawing ratio on yarn properties. As a result, significance level and optimal yarn processing parameters were obtained. Besides, the impacts of elastic yarn twist factor, spandex drawing ratio on fabric properties were also investigated, and the optimal yarn parameters were obtained.In the application, based on the theoretical and experimental studies, the characteristic in developing stretch fabric was summarized and woolen stretch fabric was successfully developed, which enriched the category of textile fabric. Experiments showed that the new developed woolen stretch fabric could meet the requirements on elasticity and handling. So this kind of fabric is technically mature and can be popularized in practical application.Ph稤. Candidate: Dang Min (Textile Material and Design of Textiles) Supervised by : Prof. Wang Shanyuan...