Enhancement of Coolness to the Touch by Hygroscopic Fibers

Abstract

Coolness to the touch of smooth, lightweight fabrics is enhanced by fibers with high moisture sorption capacity such as wool. Subjective trials to assess the coolness of fabrics in wool, cotton, polyester, and a wool/polyester blend are done under controlled environmental conditions. In paired comparisons, subjects choose the fabrics with higher moisture sorption capacity more frequently as cooler as the difference in the capacity of the two fabrics increases. Laboratory measurements show a correspondingly greater temperature drop at the skin surface during contact with the more sorptive fiber. This enhanced cooling is associated with the desorption of moisture that takes place as fabrics move toward the skin through a changing humidity environment.