关键词: 纬平针织物, 均匀化理论, 有限元分析, 线圈形态, 平幅印染

Abstract:

In order to explore the problem of easy deformation of knitted fabrics in the process of open-width printing and dyeing, a cotton plain weft knitted fabric was taken as the research object. Based on asymptotic expansion of small parameters and homogenization of multi-scale perturbation analysis under small strain, a calculation model for macroscopic and microscopic change rate of displacement and strain of the knitted fabric was built. The model was used to analyze the loop shape change under small deformation, and the results show that when the knitted fabric is stretched by uniform load, the deformation of the loop is non-uniform, and the deformation is related to the position of the loop, width and the distance between guide rollers. The convex cloth guide roller can improve the difference of loop deformation. The calculated value of loop deformation of knitted fabric is found consistent with the measured value under the uniform and non-uniform load, and the maximum error is 9.6%. This means that the combination of homogenization theory and finite element technology can be used to further analyze the macro and micro deformation of multi-component and multi-specification knitted fabrics, and it can also provide theoretical guidance for tension control of open-width printing and dyeing equipment of knitted fabric, and for the layout design of cloth guide rollers and development of roll shape (concave convex roller) of variable diameters.

Key words: weft plain knitted fabric, homogenization theory, finite element analysis, loop shape, open-width printing and dyeing