Thermal, acoustic, and hygrothermal properties of recycled bovine leather cutting waste-based panels with different compositions

This study aims to investigate the thermo-acoustic and hygrothermal properties of innovative panels made of leather waste produced by a bag factory from a circular economy perspective. Their performance was compared with other residual-based insulation panels. The leather scraps were chipped and three boards were fabricated by means of a mold with different compositions, adding adhesive glue. In order to improve the sustainability aspects, a sample was assembled by using a water-based polyurethane glue, in addition to the two panels with vinyl glue. Panels were tested for thermal, acoustic, and hygrothermal performance. Thermal conductivity values in the range of 0.064–0.078 W/mK at 10 °C were measured depending on the composition and the adhesive. A slight thermal performance deterioration occurs when using the natural water-based glue. The samples were characterized by good performance both in terms of sound absorption coefficient (Noise Reduction Coefficient NRC = 0.21–0.28) and Transmission Loss, up to 59 dB values. Water vapor resistance factor values in the 35–48 range were obtained, close to the values of standard materials, such as expanded polystyrene and polyurethane.