Urea formaldehyde impregnated oil palm trunk as the core layer for three-layered board

Abstract

Huge amount of oil palm trunks were made available during replanting activities to replace the unproductive oil palm trees. In this study, 30-years old oil palm trunks were used. The oil palm trunk (OPT) were treated respectively with different solid content (10%, 20% and 30%) of aqueous urea formaldehyde (UF) under three level of impregnation pressure 8MPa, 10MPa and 12MPa for 15min, 30min and 60min. Three-layered board was produced by laminating impregnated OPT with 0.5mm thick veneer at 180g/m2 glue spread rate and hot pressed using 6MPa pressing pressure at temperature of 110°C for 4min. It was observed that increase of impregnation pressure and time did not improve the physical and mechanical properties of the three-layered board. The results from soaking test showed that the three-layered board produced from OPT impregnated with higher resin solid content and shorter impregnation time eventually reduced the degree of water absorption and resulted in dimensional changes of its thickness and width. Furthermore, the impregnation treatments on the core layer increased the modulus of rupture (MOR) and shear strength of the board but a reduction in modulus of elasticity (MOE). The optimum UF impregnation treatment which produced the highest mechanical and physical properties was the treatment with 30% UF solid content, 10MPa impregnation pressure and 15min impregnation time.