Chord method based differentiation of tensile curves zones in elastic core cotton spun yarns

This study aims to distinguish different zones within the tensile curves of elastic core-spun yarns using the chord method and to predict the effect of the yarn count, Dorlastan® count, and Dorlastan® draft on the different zones of stress-strain curves. Yarn samples are prepared on industrial-scale spinning machines having different counts (100, 50, 33.33, and 25 tex), three elastane filaments count (156, 78, and 44 dtex), and a range of elastane drafts. The findings reveal a decreasing trend in the difference between the extreme points of the elastic zone, both in terms of elongation and strength, for all yarn counts. Furthermore, the results demonstrate a growing trend in the viscoelastic and viscoelastoplastic part on the shape of the stress-strain curves for yarns 100/156, 50/78, and 25/44 as the Dorlastan® draft and yarn count increase. Conversely, for yarns 33.33/78 and 33.33/25, the Dorlastan count emerges as a significant influencing factor. Statistical analysis reveals that the yarn count and the Dorlastan® draft exert a notable effect on the full course of the stress-strain curves of the elastic core spun yarns. These results provide valuable guidance for industry professionals in developing more durable and dimensionally stable denim fabrics.