Uniaxial Tensile Properties of Dorlastan® Core Spun Yarns: Effects of Yarn Count, Dorlastan® Draft, and Dorlastan® Linear Density on the Shape of Stress-Strain Curves

The behaviour of the tensile curve of elastic core spun yarns is not only a function of the nature and structural arrangement of the constituent fibers in yarn. Nevertheless, the variations of the yarn count, the elastane count, and the elastane draft also play a key role in defining the characteristics of the tensile curves of the elastic core spun yarns. Therefore, this study aims to distinguish different zones of the tensile curves of elastic core-spun yarns using the chord method and to predict the effect of the yarns’ count, Dorlastan® count, and Dorlastan® draft on the different zones of stress-strain curves of the elastic core-spun yarn. Yarn samples were prepared on industrial-scale spinning machines having different counts (100, 50, and 25 tex), three different counts of elastane filaments (156, 78, and 44 dtex), and various elastane drafts are considered in this study. The obtained findings revealed the decreasing trend of the difference between the extreme points of the elastic zone in terms of elongation and strength for all yarn counts. Furthermore, the results showed a growing trend of the viscoelastic and viscoelastoplastic part on the shape of the stress-strain curves of the yarns 100/156, 50/78, and 25/44 while the Dorlastan® draft increases and at the same time the yarn count increases. The statistical analysis revealed that the yarn count and the Dorlastan® draft had almost significance on the full course of the stress-strain curves of the elastic core spun yarn. This study will be an endeavor for industry personnel to achieve more durable and dimensionally stable denim fabrics.