Investigating the effect of moisture on the thermal comfort properties of functional elastic fabrics

Thermo-physiological wear comfort is mainly determined by the thermal and moisture performance of clothing. Moreover, moisture is widely recognized as one of the most important factors contributing to discomfort sensations. Functional yarns with a thermo-regulating effect improve thermal and moisture performance of fabrics, but the integration of elastic yarns into the fabric structure can impair thermo-physiological wear comfort. The goal of this research was to compare, in dry and wet states, the thermal comfort properties of elastic knitted fabrics with thermo-regulating yarns, namely Viscose Outlast® and Polyester Coolmax® to better understand thermal behavioral changes due to moisture content of the fabrics. Surface moisture transfer between the fabrics and a wet skin was also assessed and enabled to evaluate the level of the unpleasant contact feeling. Air permeability that is related to the thermal behavior was also investigated. The results obtained showed that at 22% moisture content, which simulates a sweating sensation, the change in thermal properties is similar for both fabrics. Above the ‘sweating sensation’ moisture, significant differences on the thermal properties with the moisture content were registered between fabrics, Outlast® fabric being more prone to thermal properties changes due to moisture uptake than the Coolmax® one. When worn in conditions of wet skin, the unpleasant cool feeling increased for both fabrics, but the effect is more pronounced for Outlast® fabric.Fundação para a Ciência e a Tecnologia (FCT), Ciência 2008 Progra