Recycled leather cutting waste-based boards: thermal, acoustic, hygrothermal and ignitability properties

This study investigates the possibility to reuse finished leather scraps, produced by the leather goods industry during the cutting phase, for the preparation of innovative panels for thermal-noise building insulation. Experimental panels were prepared by chipping the leather cuttings, using polyvinylacetate binder, and pressing the paste in a mold through a mechanical press. Boards were tested for thermal and acoustic performance, thermal stability, hygrothermal, wettability and ignitability properties. Acoustic measurements by means of a Kundt’s tube, and thermal characterization by means of a small hot–box system were performed. The measured thermal conductivity was 0.104 W/(mK) and 0.108 W/(mK) for the 45 °C and 50 °C set-up hot temperatures, respectively. Concerning the acoustic performance, two panels with thickness of 18-mm and 28-mm were produced: they were characterized by a noise reduction coefficient of 0.46 and 0.20 and transmission loss values in the range of 25–33 dB and 25–42 dB, respectively. Results revealed that the leather cutting waste panels were characterized by interesting thermal and acoustic performance, which are of the same order of magnitude of other residual-based insulation panels. The other analyzed properties confirmed the potential application in building insulation.