EFFECT OF WOOD/GYPSUM RATIO AND DENSITY ON STRENGTH PROPERTIES OF GYPSUM-BONDED PARTICLEBOARD FROM OIL PALM STEMS

Abstract

Three-layer gypsum-bonded particleboards were prepared from oil palm stems and tested for their strength properties. Three wood:gypsum ratios (1:2.5, 1:3.0 and 1:3.5) were used and board density was varied between 1000 to 1300 kg m^-3. The oil palm particles were not given any pretreatment and no chemical retarders were added in the wood:gypsum mixture. Boards with minimum density of 1150 kg m^-3 and wood:gypsum ratios of 1:2.5 had strength properties which were comparable to those of commercial gypsum bonded particleboards. The strength properties of gypsum-bonded particleboard were generally improved with the increase of density and gypsum to wood ratio. The highest MOR value (9.28 MPa) and internal bond (0.78 MPa) were obtained from gypsum-bonded particleboard manufactured at gypsum/wood ratio of 3.5:1 and density 1300 kg m^-3.