Study On Torsion Performance Of Ring Yarn For Knitting

The prevalence of multi-functional and top-quality knitted fabric puts forward higher requirements for its structures and properties. Spirality, the common phenomenon in single-jersey knitted fabrics not only influences the appearance of the fabric, but also causes fabric cutting waste. Many factors such as yarn properties, knitting and finishing processes, etc can affect the spirality, and previous studies indicate that yarn residual torque is the key factor. Thus, for improving yarn residual torque, it is necessary and important to investigate the method of its test and measurement. Nowadays, however, the test and measurement of yarn torque is a complicated and expensive operation, and unsuitable for practice application. Recently, it is found that yarn residual torque can be expressed by using yarn wet snarling turns, but it lacks theoretical verification.After analyzing the manufacturing processes of singles yarn and plied yarns, in this study, a mathematic model was established by using energy method for explaining the torque behavior of these singles and plied yarns. And the model was verified and analyzed with the help of a VB written program.For discussing the relationship between the spinning parameters (such as yarn linear density and twist factor) and properties of the resultant ring spun yarns, in this study, experiments were designed and analyzed by using the Response Surface Methodology (RSM) for investigating the influences of the parameters on yarn properties. Moreover, optimization was carried out and optimum parameter combinations were found. This lay a foundation for further investigation.In addition, the analysis of the effect of yarn parameters on the properties of resultant plain fabrics were also involved in this paper, and several experiments were conducted. The results show that, under experimental conditions, the properties of the fabrics knitted with the yarns having parameters of linear density of 28tex-31tex and twist factor of 3.0 tpi/Ne1/2-3.2 tpi/Ne1/2 meet the requirements. This makes a bridge between yarns parameters and the properties of resultant fabrics, and providing experimental evidences for material selection before knitting.