Investigation of thermal and solar properties of perlite coated woven fabrics

In this study, thermal insulation and solar properties of polyester woven fabrics which were coated with micronized perlite having three different particle sizes (10-38, 50-63, and 100-150 mu m) at four different concentrations (20, 40, 60, and 80 g/kg) were investigated. The coating process was performed according to the knife-over-roll method. Thermal measurements were carried out with two different principles to evaluate contact and radiant heat transfer according to JIS R 2618 (testing method for thermal conductivity of insulating fire bricks by hot wire) and EN ISO 6942 (protective clothing-protection against heat and fire-method of test: evaluation of materials and material assemblies when exposed to a source of radiant heat), respectively. Perlite coating enhanced the thermal insulation property of fabrics. The lowest thermal conductivity coefficient and heat transmission factor (0.088 W/mK and 26.83%) values were obtained at the maximum concentration with the biggest size perlite. With the increasing perlite concentration, solar transmittance values decreased for all particle sizes while solar reflectance values increased.