The influence of low-density (Paulownia spp.) and high-density (Fagus sylvatica L.) wood species on various characteristics of light and medium-density three-layered particleboards.

This study investigates the influence of wood densities on moduli of rupture and elasticity, internal bond strength, surface soundness and density profiles of light and medium-density three-layered particleboards (PB). Therefore, particles of low and high-density wood species in three-layered PB were combined. Different combinations of beech (Fagus sylvatica L.) as high-density wood species and kiri (Paulownia spp.) as low-density wood species were used as material for the core and surface layers of PBs with target densities of 500 and 650 kg/m³. The results of all tests were influenced by the interaction of two effects: the different densities of the raw materials and the different level of compaction (effectiveness of glue utilization). For target density 500 kg/m³, the compaction of the kiri particles had a greater influence on strength results, than the higher density of the beech raw material. With increasing the target density from 500 to 650 kg/m³, a shift of the dominating effect occurred from effective glue utilization due to compaction towards the effect of the raw material density. The low-density raw material showed minor percentage changes than the high-density raw material. [ABSTRACT FROM AUTHOR]