Innovative porous panels made from alpine tree bark-fibre bundles for enhanced acoustic and thermal insulation

To tackle climate change, raw material shortages and global competition, new technologies should better utilize existing resources. Tree bark, an abundant by-product from Alpine sawmills, offers a promising opportunity despite its heterogeneous nature. In this study, tree bark was homogenised into fibrous material and subsequently processed into novel binder free low-density and therefore porous fibreboards. The aim was to develop effective panels for acoustic and thermal insulation by varying the key parameters bark species, fibre size, density and its variations. The findings highlight the effectiveness of bark fibre-based panelss as thermal and acoustical insulators, achieving densities of 170–330 kg/m³, a noise-reduction coefficient (NRC) exceeding 0.5 for most specimenss, and thermal conductivity below 0.08 W/(m·K). Significant variations in fibre length, density, and tree species indicate the need for tailored manufacturing adjustments. Testing involved impedance tube methods for sound absorption and dynamic plane source tests for thermal properties. This study provides initial validation of this approach, underscoring its potential for future research in utilising tree bark effectively.