The study aims were to investigate the Thermophysical properties of fir wood (Abies alba Mill.) using the Hot Disk transient method under standard room conditio

This study investigated the effect of substituting wood fibres with pine needles on the properties of low-density fibreboards (LDFs). Boards were produced with 0%, 25%, 50%, 75%, and 100% needles content, and their physical (density, density profile, mat compression ratio, water absorption), mechanical (compressive strength at 10% deformation, internal bond), thermal (thermal conductivity, thermal diffusivity, heat capacity), and acoustic (sound absorption coefficient, noise reduction coefficient) properties were investigated. Partial substitution of wood fibres with needles affected board structure and performance. Average density remained unaffected, but higher needle contents increased local density variations and reduced cross-sectional compactness. Mechanical strength decreased with higher needle content, while boards with up to 50% needles maintained compressive strength and internal bond. Water absorption increased with needle incorporation, but moderate substitution had negligible effect on moisture resistance. Thermal conductivity and diffusivity decreased with higher needle content, enhancing insulation performance, while heat capacity remained unaffected. Acoustic properties improved with needle addition, resulting in higher sound absorption and noise reduction. Overall, partial substitution of wood fibres with pine needles enabled the production of LDFs with optimized physical, mechanical, thermal, and acoustic properties. Among the tested variants, boards containing 50% needles were identified as optimal, offering a favourable combination of structural homogeneity, mechanical strength, and insulating performance. These findings highlight the potential of pine needles as a sustainable alternative biomass for environmentally friendly LDFs with multifunctional properties.