Influence of Washing on the Thermal Comfort Parameters of Denim Fabrics with Varying Elastane Content

The enduring popularity of denim in the global apparel market is attributed to its outstanding durability, resistance to repeated laundering, and versatility in adapting to changing fashion trends, making it one of the most widely used fabrics in the textile industry. The incorporation of elastane into denim fabrics enhances their elasticity and improves the wearer’s freedom of movement. In addition to stretch performance, optimizing the thermal comfort of stretch denim fabrics has become an important aspect of advanced textile material development. Unlike previous studies, this research provides a comprehensive evaluation of the combined effects of elastane content and repeated home laundering on the structural and thermal comfort properties of stretch denim fabrics. Five denim fabrics containing different elastane ratios were produced, and their dimensional shrinkage, fabric weight, thickness, fractional cover, thermal resistance, air permeability, and relative water vapor permeability were determined before and after five laundering cycles. Statistical analyses were performed to evaluate the effects of elastane content and laundering. The results demonstrated that laundering induced significant structural changes, including increased dimensional shrinkage, fabric weight, thickness, and fractional cover, which consequently altered the comfort performance of the fabrics. Thermal resistance and relative water vapor permeability increased after laundering, whereas air permeability decreased significantly (p < 0.05). Correlation analysis further revealed strong statistically significant relationships between the structural characteristics and the measured comfort properties, confirming that both elastane content and laundering are key factors governing the thermal comfort performance of stretch denim fabrics. These findings provide valuable guidance for optimizing the design and laundering performance of stretch denim fabrics with improved thermal comfort and may also contribute to future studies involving functional and technical applications of denim materials.