Effect of Washing Cycle on Tenacity and Stretching Properties of Denim Fabrics Containing Elastane

Elastane containing denim fabrics which are known as “blue jeans” have always been popular. Denim fabrics are woven with white elastane-cotton weft yarns and 100% cotton indigo dyed warp yarns. The most distinctive feature of denim fabrics is those warp yarns’ indigo color fading after washing processes which enhance the denim fabrics having unique structures. The elastane amount in the weft yarns determines the flexibility ratio of the denim fabric with its high recovery property. This study aims to investigate the denim fabrics produced at three different weft and warp density with different yarn counts and elastane ratios in terms of tenacity and stretching properties (elongation, permanent elongation, elastic recovery) considering the washing cycles of 0, 5 and 15. Three different denim fabrics with 100% cotton warp yarns and cottonelastane weft yarns were produced at the weft densities of 23,19, 24 (pick/cm) and at the warp densities of 33, 28 and 35 (end/cm) with three different elastane percentages of 4%, 1% and 2.5% respectively. The 2/1 twill denim fabrics were produced on dobby weaving machine. Home laundry process was applied at 30°C for 40 minutes by using 20 ml/kg standard reference detergent containing 5%-15% anionic surface active agents, <0.5% non-anionic surface active agents, soap, enzyme, preservatives and perfumes. Home drying process was applied for 40 minutes after each washing cycle. In order to evaluate the mechanical properties such as breaking tenacity and stretching; the testing devices of Shimadzu and Fyrma fabric extensometer devices were used. As a conclusion tensile and stretching properties of three different denim fabrics varied with the washing cycles.