The effect of storage time and humidity on mechanical and physical properties of medium density fiberboard (MDF) from oil palm empty fruit bunch and rubberwood

Commercial medium density fiberboard (MDF) was produced using rubberwood and oil palm empty fruit bunch (OPEFB) based on oven dried weight. Relative humidities of 65%, 93% with fixed temperature at 20 degrees C, and normal condition was used for storage of the boards. The effects of storage time and relative humidity of MDF were assessed by measuring the changes of the board mechanical and physical properties for 10 weeks at 2 week intervals. The mechanical tests involved were internal bonding and flexural test, whereas physical tests were moisture content, thickness swelling, water absorption, and scanning electron microscope. The result showed that at 65% humidity, MDF exhibited a lower effect on the mechanical and physical properties of the panel, whereas at 93% humidity, the panel exhibited a decrease in the dimensional stability and mechanical properties of the board. Possible mechanisms behind this reduction are discussed.