Effect of hot-pressing and hydrothermal parameters on recycled wood particles and particleboards

This study investigates the characteristics of particles recycled from waste particleboards and the factors that lower the physical and mechanical properties of recycled panels. Hot-pressing with/without adhesive and hydrothermal treatment are applied to the fresh wood particles, and the morphology, surface properties, and mechanical strength of the particles after treatments are investigated. The results indicate that hot pressing causes the densification of particles, resulting in reduced wettability, a low compaction ratio, and a loss of particle strength; thus, the mechanical properties of recycled panels are significantly weak. The residual adhesive also affects the wetting of the adhesive. Hydrothermal treatment helps to recover the cellular structure and compaction potential of recycled particles, thus improving the mechanical properties of recycled panels. The deteriorations in particle qualities are mainly due to densification and residual adhesive, and hydrothermal treatment helps to recover the structure and remove the resin on the recycled particles.