The study of the effect of moisture regain on yarn breakages during knitting.

Abstract

Yarn conditioning is very important in textile processing since the amount moisture in textile fibres affects the physical and mechanical properties of fibres and yarns. This eventually affects the knitability and weaveability of textiles. Though many factors affect yarn properties and quality, this research was intended to determine the effect of moisture, an inherent factor that determines the strength and elongation of cotton fibres and yarns. In this research, physical and mechanical' properties of the unconditioned yarn such as percentage elongation count strength product, yarn evenness (thick places, thin places and neps) were tested and compared with those of conditioned yarn. Two conditioning methods were used, i.e., the steaming method of conditioning and the conditioning in room method (conditioning by acclimatization). In the steaming method, the yarn bobbins were steamed for 30 minutes at 70 0C and then cooled for 3o minutes before testing. In the conditioning in room method, the yarn packages were stored in the air conditioning room at 75 0/0 R H for three days after which the yarn properties were tested. The yarn bobbins sampled were 100% carded Cotton yarns. Yarn samples of unconditioned and conditioned yarns were each knitted on the circular knitting machine thirty minutes at a running speed of 10 RPM and the number of yarn breakages and their possible causes were recorded for both samples. The machine efficiencies for the two knitting operations were determined. It was found that conditioned yarn presents fewer yarn breakages and a higher efficiency of knitting is achieved when knitting conditioned yarns as compared to unconditioned yarn. The findings in this research provide empirical evidence that alerts textile mills to prioritize yarn conditioning in order to improve efficiency of' knitting, increase productivity and profitability of the knitting room.