The Analysis Of Mechanism On Spirality Of Single Jersey Fabrics And The Discussion About How To Control It

Along with the improving of living standard, the demand of both comfort and appearance of garment becomes higher and higher. Spirality knitting fabric has bothered enterprises for a long time, and has made bad influences to the appearance of garment. Though a great many of researchers have been made to solve this problem, there is no thorough solution. This thesis will try to decrease spirality by using steaming process.This thesis uses cotton yarns and polyester/cotton blended yarns as knitting material, and knitts single jersey fabrics on circular knitting machine. It analyses and designs the method to test the twist liveliness of yarns and the index to test the spirality angle of the fabric.The thesis analyses that the twist liveliness was arisen from the stress that hasn't released when yarns were twisted. When the material isthe same, the bigger yarn twist is, the bigger twist liveliness is, and the bigger spirality of the fabric is. Therefore, if you want to decrease the spirality, you should find a method to decrease the yarn twist liveliness.After studying the effect of spirality that yarn twist and twist direction caused, we can conclude that the spirality of polyester/cotton blend fabrics will enlarge while the blended percentage of polyester becomes higher.In this thesis, steaming process is used to steady the yarn twist, and the spirality can be decreased. After steaming, we can find that yarn intensity and tensibility are affected. There are different influences for different kinds of yarns. Steaming can steady the yarn twist liveliness very well, and it has better effect on polyester/cotton blend yarns than cotton yarns.Compared rough fabrics with dyed fabrics, we can find that dyed fabrics are tighter than rough ones, which are good for decreasing spirality. The polyester/cotton blend fabrics which are disperse-dyed have smaller spirality than which are active -dyed. In the thesis, we compared the effect of active-dyed polyester/cotton blended yarns with that of disperse-dyed ones. We found that dying process could decrease spirality. And different processes will make different effects on spirality.After comparing the effect of steaming process that to release yarn stress with that of natural releasing, the first saves a lot of time and hasbetter effect. The experiments find that steaming can steady yarn twist liveliness.