Using Phase Change Materials in Clothing

When microcapsules of phase change materials (PCMS) are added to textiles, they absorb heat energy as they change from a solid to a liquid state and release heat as they return to a solid state. This project quantifies the effect of PCMS in clothing on heat flow from the body during temperature transients. One- and two-layer body suits are constructed of a fabric/foam laminate produced with and without PCMS, and heat loss from a thermal manikin is measured as it is moved from a warm chamber to a cold chamber and back again. The results indicate that the heating and cooling effects last approximately 15 minutes. Heat released by PCMS in a cold environment decreases body heat loss by an average of 6.5 W for a one-layer suit and 13.2 W for a two-layer suit compared with non-PCM counterparts. PCM cooling effects increase body heat loss in a similar manner; therefore, PCMS in clothing provide a small, temporary heating/cooling effect during environmental transients.