Hygro-Thermal and Acoustic performances of recycled textile-based materials for building applications

This study presents an experimental investigation of the heat transfer and acoustic properties of semi-finished panels obtained from post-consumer textile waste. Their different compositions (mostly polyester, mostly cotton, and mixed fabric) and different densities, in a range from 50 to 150 kg/m 3 , were considered. The transient “hot disk” method was used for thermal conductivity and diffusivity measurements and a Kundt's tube for sound absorption. Moreover, hygroscopic characterizations of moisture absorption and its kinetics were carried out. Overall, good thermal insulation (thermal conductivity between 0.042 and 0.062 W/K/m) and medium acoustic performances (sound absorption classes C and D) were observed, suitable for building applications. Thermal conductivity was found to linearly increase with the density and to increase with the relative humidity, in line with the analysed hygroscopic behaviour of the porous matrix. On average, the polyester-based panels showed the lowest thermal conductivity, followed by the mixed fabric. • For all the materials thermal conductivity was found to be in the range of 0.42–0.62 W/m/K, it linearly increases with panel density, in a range of 60–160 kg/m 3 . • The lowest thermal conductivity was obtained with the polyester based panels. For the cotton based it is on average 26 % higher. Mixed composition have intermediate insulation performances. • For the measurements with transient “hot disk” method of the thermal properties in different environmental conditions was set a procedure that takes into account the specific kinetics of moisture absorption. • Thermal conductivity increases with relative humidity in line with the hygroscopic characterization of the semi-finished materials • For all compositions, densities and thicknesses investigated, samples belong either to C or D sound absorption class. Better acoustic absorptions have been observed for medium-high density panels, regardless of the material composition.