The Structure And Property Of Natural Colored Cotton Yarns And Their Knitwear’s Property Analysis

Environmental protection consciousness was strengthened gradually since 20th century. The processing of ordinary natural textile often remains the blanching, dyeing and finishing which will bring some harmful object including the formaldehyde, synthetic dye and so on. While the natural colored cotton avoided the traditional dyeing processing, so researching and developing the natural colored cotton textile becomes the effective method can get over the green barrier in international textile trade. But the natural colored cotton yarn made from the traditional process still exists in the flaw of low force, more hairiness, over soft from the present situation. In view of the limitation, we hope can improve the property of colored cotton textile through using new spinning process.Jet vortex spinning is a new technology developed in last few years. This kind of yarn possesses little harmful hairiness, big rigidity and other remarkable characteristic. So this paper hoped to improve the colored cotton yarn through this new way. In view of the characteristic of natural colored cotton, so we take blended spinning with the white cotton and design two kinds blending of 80/20 and 15/85 including four kinds spinning methods of ring spinning, open rotor spinning, the jet spinning and jet vortex spinning in order to contrast analysis comprehensively the yarn structure, property and the fabric performance of natural colored cotton for the purpose of providing some instruction for natural colored cotton product.Firstly, it briefly introduced the basic principle of four kinds spinning technology in this paper, emphatically analyzed the effect of components of spiral needle, hollow spindle and the parameters of nozzle pressure, delivery speed and nozzle distance of the jet vortex spinning yarn on the property of yarn. Then three process parameters including nozzle pressure, nozzle distance and delivery speed of jet vortex spinning is optimized by means of quadratic universal spinning modular design to gain the optimum process parameters. The result explains that P=0.4MPa, L=19mm,V=320m/min can make super yarn.Then test the basic mechanics performance, CV, friction coefficient, abrasive resistance, hairiness, bulkiness and the relaxation, torque performance of the four kinds of yarn. The experiment result indicated that the jet vortex spinning yarn surface fiber arrangement closely. The surface fiber has a angle with yarn axes which shows the spiral path distribution, it is similar with the twist structure of ring spinning yarn. And also the yarn is bright and clean. The property of yarn is decided by the structure, so the breaking force of this yarn is about equivalent 80% of the ring spinning yarn, it is better than other new yarn’s. The friction coefficient is the biggest of four yarns. But the CV is inferior to ring spinning yarn, While abrasive resistance and bulkiness are both worse than open rotor spinning yarn’s, but surpass other yarn. The yarn basically has no above 3mm harmful hairiness that can effectively get over the flaw of natural colored cotton yarn. The jet vortex yarn has a lower residual torque compare with ring spinning yarn, which can monish the distortion property of plain knit fabric.Then based on the test and theoretical analysis, analyze the relaxation property of yarn using four-element model, the equation of the stress relaxation process is built up using the principle of Boltgation superposition. The relaxation timeτof jet vortex spinning is relatively short, so the stress of yarn loss more quickly, so it should have the advantage in the dimensional stability of latter product.Finally analysis the property of natural colored cotton knitting made from different yarn. The fabric made from different yarn structure show different performance and the style. The fabric of jet vortex spinning owns a better bursting force, stronger abrasive resistance and also can effectively improve the anti-pilling property, its stability of appearance obviously possesses the superiority and the fabric air permeability also surpasses the fabric made from ring spinning and open rotor spinning yarn. The flexible rigidity and drape coefficient of jet vortex spinning yarn fabric are relatively big, so it can effectively improve the shortcoming of over soft performance. Its bulkiness also surpasses other fabrics.