Preparation of thermoplastic molding from steamed Japanese beech flour

Thermoplastic molding has been prepared from beech wood flour steamed at 180°C or at higher temperatures without any additives. It exhibited a smooth and lustrous surface and had a high density of approximately 1.45 g cm-3. The internal structure of molding revealed that the flour particles were completely surrounded by black resin-like substance which was thermoplasticized by heat and pressure during the molding process. The chemical composition of the steamed flour and physical properties of molding were examined as a function of steaming temperature. Maximum bending strength and Young's modulus of molding reached 63 MPa and 11 GPa, respectively, at 180°C of steaming, which were much higher than those of a hardboard. The water absorption of the molding was 8% or less and decreased with the steaming temperature.