Structure And Properties Of Naturally Colored Cotton (NCC)/Silk Blend Yarn And Product

Naturally colored cotton/silk(NCCS) blend fabric is a new type of environmentally friendly product. It combines the luster of silk, the soft touch of colored cotton and good features such as moisture permeability. Silk-based textiles containing naturally colored cotton (NCC) need no dyeing, for the color has been inherent in fiber. The products can meet requirements of environmental protection and healthy consumption; NCC-based textiles containing silk can not only maintain the natural style of cotton fabric, but also have improved luster and wearability. Therefore the blended fabric will complement each other's advantages, and its environmental friendly characteristics become even more significant. Furthermore, colored cotton fibers and silk fibers are green fibers, and the natural environment-friendly products which are blended with the two kinds of fibers can significantly improve the quality and grade of the products.In this thesis, a series of high-quality NCCS blend yarn was successfully prepared. During the yarn spinning process, the problem that the length of naturally colored cotton fiber was too short to be spun high quality yarn was solved. Compared with ordinary NCC yarn, the tensile strength and elongation at break of the NCC (brown)/spun silk yarn prepared were significantly increased, and yarn physical performances of yarn evenness, thin and thick were improved significantly, while neps and hairiness of the yarn had no significant impact.Studies have shown that the tensile properties of the woven fabric prepared by such yarns were improved significantly. With the spun silk content increasing, the hand of the naturally colored cotton (brown)/ silk fabric became relatively smooth, soft, while shapeability of fabric became worse. Furthermore, the wicking effect of the knitted fabric prepared by such yarn was improved obviously, while permeability of the fabric was decreased. The combination of NCC and silk was very beneficial to improve the heat-moisture comfort of fabric.According to different washing methods of Europe, America, and our country's styles, the washing liquor temperatures at room tempature, 60℃and 90℃on the fabrics with different blend ratio were specifically used for investigation. By comparing fabric structure, color, wearability and hand changes after washing at different conditions, the effect of blending ratio on the washing properties of fabric, as well as different temperatures and washing cycles on the fabric washing performance were analyzed.Addition of spun silk can improve pilling phenomenon of NCC blend fabric after washing. The higher the washing temperature was, the more loose fiber at fabric surface had. The structure and surface morphology of NCC blend fabric changed most by the first washing cycle. After first washing cycle, the permeability of fabric decreased significantly, and followed unchanging with washing proceeding. With the proceeding of the washing, the△E of fabric color was gradually increasing. Washing temperature had great impact on color alteration.The effect of washing temperature on the wicking effect of NCCS blend fabric was significant. Increasing washing temperature was helpful to remove pectin on the surface of cotton fiber, resulting in improved wicking effect of NCC, and indicating the heat-moisture comfort of NCC blend fabric can be improved by high-temperature washing.The fabric with low content of silk was softer and more fullness and the one with high content of silk relatively smoother. The stiffness of fabric with low content of silk was better than that with high content of silk. The surface thickness of fabric was impacted greatly by washing temperature, which had less influence on the sheering stiffness of fabric. The shapeability of fabric was improved after washing. The first washing cycle had the most influencent on the hand of fabric with different washing conditions. Overall, there was no significant hand difference existed in different blend ratio and washing temperature after washing.The studies showed that the NCCS blend material was a kind of very hopeful product with environmental friendly characteristics and significantly improved performances.