EFFECT OF CHEMICAL TREATMENTS ON THE CHARACTERISTICS OF REGULAR AND COMPACT COTTON SPUN YARNS

Abstract

An investigation on the physical properties of compact and conventional spun yarns following chemical treatments is reported. In this research, the effect of chemical finishing treatments namely, scouring, hypochlorite bleaching, peroxide bleaching, mercerising and dyeing on the yarn characteristics of 30 Ne regular and compact ring spun yarns has been studied. The results showed that whilst tenacity of treated yarns rose, elongation fell with the exception of slack mercerising treatment. Work of rupture was significantly higher than that of control for slack mercerised samples. With the exception of slack mercerised yarns there was no measurable difference in initial modulus of yarns. While bleached yarns samples showed somewhat poor abrasion resistance, the other treated yarns did not show any change in abrasion resistance. All the treatments had led to an increase in yarn friction. Slack mercerisation treatment had led to a significant increase in shrinkage and the shrinkage values were identical in both conventional and compact yarns. The other treatments had resulted in lower shrinkage values. Compression was found to be greater for compact yarns in untreated state and all the treatments had lowered the compression. Compressional energy (WC) was found to be the highest for compact mercerised yarn. Scanning electron micrographs showed clearly the improved hairiness and bulk in compact yarns.