The use of phase-change materials in clothing.

摘要

When microcapsules of phase change materials (PCMs) are added to textiles, they absorb heat energy as they change from a solid to a liquid and generate heat as they return to a solid state. This project quantified the effect of PCMs in clothing on heat flow from the body during temperature transients. One and two layer body suits were constructed of a fabric-backed foam produced with and without PCMs. The heat loss from a thermal manikin was measured as he was moved from a warm chamber to a cold chamber and back again. The results indicated that the heating and cooling effects lasted approximately 15 minutes. The heat generated by PCMs in a cold environment decreased body heat loss by an average 6.5 W for a one layer suit and 13.2 W for a two layer suit as compared to their non-PCM counterparts. In two layer suits, more heat was produced when the PCM layer was on the outside than when it was next to the body, probably because not all of the PCMs solidified near the warm body. When only half of the body was covered with PCM garments, the heating effect was reduced by half compared to the PCM suit with full coverage.; Ski jackets and pants were also made of the fabric-backed foam—with and without PCMs—and a woven shell fabric. Sixteen male subjects wore the ski garments during a 1% hour exercise/rest protocol which simulated skiing. The subjects' leg skin temperatures were significantly higher when they moved from sitting in a warm chamber to a cold chamber while wearing PCM garments. However, no statistically significant differences were found in skin temperatures for subjects wearing PCM garments as compared to non-PCM garments during alternating exercise and rest in the cold. Likewise, no significant differences in overall thermal comfort were found. However, the subjects felt significantly more clammy in the PCM ensemble, and there was significantly more unevaporated sweat in the PCM ensemble, probably because the PCM material had a higher evaporative resistance. In conclusion, PCMs in clothing provide a small, temporary heating/cooling effect during environmental transients.