Effect of thermomechanical treatment on physical properties of wood veneers

Thermomechanical modification is a technique that allows wood densification, improving mechanical properties and reducing hygroscopicity. In veneers, this technique is commonly used to improve bonding quality in wood based panels. This study aimed to evaluate the effect of thermomechanical modification on some physical properties of rotary peeled veneers of amescla (Trattinnickia burseraefolia). Veneers were treated in a hydraulic press at 140 and 180°C, for 1 and 2 min at 2·7 N mm⁻² pressure. The apparent density was evaluated as well compression ratio, weight loss, equilibrium moisture content, thickness swelling and water absorption. The results showed that apparent density and compression ratio increased after treatment. Equilibrium moisture content values were lower in samples treated at 180°C. Dimensional stability was not improved due to release of compressive stresses. The surface of veneers was modified and its roughness and wettability were reduced significantly.