Bursting Strength of Core Spun Cotton/Spandex Single Jersey and 1×1 Rib Knitted Fabrics

Abstract

This research work investigates the bursting strength of core spun cotton/spandex and 100 % cotton, single jersey and 1×1 rib knitted fabrics, made with low, medium and high fabric tightness factors obtained using three machine set stitch lengths. These knitted fabric samples were relaxed under the dry relaxation to full relaxation and further relaxation up to 5th washing cycle treatments. For wash relaxation treatments, full relaxed samples were used. Course and wale densities, stitch densities, fabric thickness and bursting strength of the samples were measured at the end of each relaxation stage. Thus, before commencing the dry relaxation treatment, machine off stitch lengths of samples were also measured. It was found that, structural parameters, and fabric thickness increased with the progression of relaxation of fabrics and they depend on the fabric tightness factor (stitch length⁻¹). Single jersey and 1×1 rib cotton/spandex knitted fabrics showed higher structural parameter values and higher fabric thicknesses than similar types of structures produced with cotton knitted fabrics at each of the relaxation treatments, even though they had the same machine set stitch lengths. Also, cotton and cotton/spandex 1×1 rib fabrics gave higher structural parameter values than their single jersey fabrics. Cotton single jersey and 1×1 rib fabrics gave comparatively higher bursting strengths than their cotton/spandex fabrics and bursting strength has gradually increased with progressing of relaxation treatments done. However, bursting strength of cotton/spandex 1×1 rib fabrics has gradually decreased with progressing of relaxation treatments, due to their longer tumble drying duration, where as cotton/spandex single jersey fabrics showed an increasing tendency of bursting strength under progressing of treatments, due to the lower tumble drying duration applied than their 1×1 rib fabrics. It was also found that the fabric tightness factor or stitch length, relaxation states of single jersey and 1×1 rib fabrics, fiber content of the yarns in these knitted fabrics and knitted structure type are significantly effect on structural parameters such as course and wale density and stitch density, fabric thickness and bursting strength of these tested knitted fabrics, under the 95 % significant level. In addition, the fiber content and the structure type are very important to consider for the bursting strength of knitted fabrics, when these knitted fabrics are subjected to tumbler drying. Thus, yarn strength can give a significant effect on bursting strength of these knitted fabrics.