Physical and Mechanical Properties of Medite® MDF Exterior from Acetylated Wood Fibers

Abstract: Currently, the demand for wood-based panels has been growing solidly in European countries. Medium density fibreboard (MDF) manifests the potentialities for outstanding physical and mechanical properties. However, MDF from different fiber sources is normally designed for internal applications due to the poor moisture resistant capability. This study was conducted on acetylated MDF (Medite® MDF Exterior) to evaluate how physical (i.e. density, moisture content, dimensional stability, thickness swelling) and mechanical (i.e. modulus of elasticity, internal bonding strength before and after accelerated aging, bending stiffness and bending strength) properties behave at different relative humidity (i.e. 35 %, 65 % and 85 % RH at constant temperature of 20 ℃) levels. Bending stiffness was measured non-destructively by means of resonance method. The material used for control samples was commercial MDF. The size, quantity, conditioning and test method were followed in accordance with respective standards. The results showed that physical and mechanical properties were less influenced by Medite® MDF Exterior compared to commercial MDF. Medite® MDF Exterior were superior to commercial MDF in moisture resistance. Medite® MDF Exterior had more stable mechanical properties than commercial MDF with the changes of relative humidity.