Impregnation of textiles by phase change materials (PCMs) changes their thermal properties. High thermal capacity of PCMs, due to large enthalpy of phase change (latent heat), increase the potential of these materials for heat accumulation, but also modifies heat transfer in transient states what improves their insulating characteristics. Textiles with PCM, as functional materials, are used in wide area of applications. For the first time they were used in clothes for space applications. Currently, they find applications for sports wear and accessories (gloves, helmets etc.), protective overalls for firefighters, metallurgists. Medical applications for surgical apparels, patient bedding materials, bandages and products to regulate patient temperatures in intensive care units are also worth mentioning. Textiles with PCM are also considered for the use in buildings, in the form of, e.g. window blinds, wallpapers, to accumulate heat or cold, thus improving thermal comfort inside the room. The paper presents selected results of both experimental and theoretical investigation of the thermal behavior of textiles impregnated with phase change materials, PCMs, under variable thermal loads. Thermal capacity of textiles containing different amounts of microencapsulated PCM were measured with DSC. Then, their thermal behavior characteristics were investigated under irradiation from a solar simulator (heating phase) and during cooling in the regime of natural convection. Mathematical model of heat transfer in the textiles, including radiative and convective boundary conditions, was formulated. Computer simulations of the processes under study, validated on the base on experimental results, allowed to determine important properties of the textiles, such as coefficients of absorption and transmissions for solar radiation. Overall thermal characteristics of the textiles, i.e. temperature variations under different thermal loads, are also presented in the paper.

DOI: https://doi.org/10.3846/enviro.2017.260