Effect of Wool Components in Pile Fabrics on Water Vapor Sorption, Heat Release and Humidity Buffering

Experimental measurements of water vapor sorption and desorption in wool/polyester blend fabrics are used to assess associated changes in temperature and heat flux during varying relative humidity levels. The results aid further development and adoption for military applications of cold-weather wool blend fabrics that are more flame resistant and warmer than 100% polyester garments. Two types of bi-sided fabrics were tested: 1) thin knit fabrics designed to be worn next to the skin, usually as undergarments, and 2) thick fleece mid and outer layers with 100% wool on the outer face and 100 % polyester on the inner surface. The following issues were addressed: 1) the effect of wool content on the knit fabrics, 2) the effect of fabric orientation on both the knit and the fleece fabrics, and 3) the effect of durable water-repellent treatment on the fleece fabrics.