Influence of anisotropy and yarn count on the modulus of elasticity of weft rib knitted fabric

Abstract

Knitted fabrics are elastic orthotropic materials. This paper analyzes the effect of anisotropy of knitted fabrics and yarn count on the value of breaking force, elongation at break and initial modulus of elasticity under the action of tensile forces on samples that were cut at different angles to the direction of knitting. Four types of weft rib knitted fabrics with different fineness of single cotton yarn were tested. For different angles of cutting samples, initial modulus of elasticity were determined experimentally in the laboratory. Deviations were calculated and they show good agreement between experimental results and the calculated values of initial modulus of elasticity, so the theoretical equations can be used with high accuracy to calculate the initial modulus of elasticity of knitted fabrics in various directions. Therefore, the measurements need to be implemented when the tensile force acting on the knitted fabric samples which are cut in the direction of courses, wales and at the angle of 45°. It has been proved that with the increase of the value of yarn count, the values of initial modulus of elasticity and breaking force increases, while simultaneously elongation at break decreases.