Investigation of the physical and mechanical properties of lightweight particleboard bonded by foamable polyurethane adhesive

The objective of this study was to investigate the manufacture process and basic properties of particleboard using foamable polyurethane adhesive. The foaming and curing behaviors of the polyurethane adhesive were analyzed using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The PressMAN hot-pressure monitoring system was used to obtain the internal temperature and gas pressure in the mat during the hot-pressing process. The effects of the hot-pressing temperature, time and mat structure on the physical and mechanical properties of lightweight particleboard were investigated to optimize the process parameters. Results showed that the peak foaming and curing temperatures of the polyurethane adhesive were around 75 °C and 95 °C, respectively. The core layer temperature of the particleboard reached the required temperature for foaming and curing when hot pressing. The lightweight particleboard that was hot-pressed at 180 °C for 5 min had a density of 0.5 g/cm3. At a mass ratio of the surface layer to the core layer of 1:3, the lightweight particleboard exhibited a good vertical density profile, as well as excellent mechanical properties. This study demonstrates that lightweight particleboard can be successfully fabricated using foamable polyurethane adhesive without free formaldehyde release.