Abstract

Oil palm trunk biomass, abundant in tropical zones, can be utilized as raw materials for lumber-based products to serve the growing building industry; however, its relatively poor mechanical properties must be improved to meet structural requirements. This work aims to improve the properties of oil palm wood as a raw material for glued-laminated timber via thermal compression. Low-density (191–350 kg/m³) and medium-density (350–530 kg/m³) oil palm wood were thermally compressed at 200°C for 1 h with 40% and 25% target compression ratios, respectively. The thermally compressed oil palm experienced different degrees of compression throughout its thickness, which determined its density profile. Thermally compressed medium-density wood had a more uniform density, which makes it more favorable for structural usage allowing simpler connection design. Only the bending and tensile strengths in the parallel-to-grain direction of the thermally compressed medium-density wood met the requirements of a specific class of structural softwood timber. Block shear tests were performed to evaluate the feasibility of face-bonding the thermally compressed wood using a two-component polyurethane adhesive. All block shear test specimens had 100% wood failure percentages. Thus, the thermally compressed medium-density palm wood can be used for glued-laminated timber production under a condition where its own structural grade is established.