Enhancement of low-density particleboard properties by core layer particle orientation
Three layer particleboards of 500 and 650 kg/m3 target density were made by spreading the core layer wood particles between upright positioned caul plates with the intention of partial vertical orientation. This procedure was assumed to increase the core layer compression resistance and, thus, counteract decreased panel properties in lightweight particleboard manufacture. While internal bond strength and thickness swelling were significantly improved, bending properties were on the same level as those of the references with conventional particle orientation. Density profiles were found to be just slightly more pronounced. The lack of improvements was explained by the changed structural set-up and, thus, lacking of core layer support.