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 180uC, for 1 and 2 min at 2?7 N mm 22 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 180uC. 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.

This experiment evaluated the utilization of the recently identified Brazilian giant bamboo, Guadua magna (Londoño & Filg.) to manufacture medium density particleboard. Four board types were tested: two of them exclusively with particles of bamboo and two in a mixture of bamboo with Pinus taeda wood particles. The target density of the panels was 0.65 g/cm 3 for all treatments. The particleboards were bonded using 8% content of urea-formaldehyde (UF) and phenol-formaldehyde (PF) resins, based on dry weight mat. Mechanical, physical and nondestructive properties of the panels were assessed. The particleboards produced with PF showed better dimensional stability than UF particleboards. The addition of wood particles improved the mechanical properties of E M , f M and IB. The flexural properties of the panels (E M , f M ) could be modeled using either E Md or density and the models fitted presented high predictability (>66%).

In the first part of this study, the feasibility of manufacturing resin-bonded particleboard from the recently identified Brazilian giant bamboo (Guadua magna) was evaluated. In this second part, the main goal was to study the material properties of the cement and gypsum-composites made from that bamboo species. The effect of CaCl 2 addition in the physical and mechanical properties was also evaluated. Initially, the hydration test was performed to determine the inhibition index of the bamboo particles in the cement and gypsum setting. Three concentrations of CaCl 2 were used to produce bamboo cementbonded particleboards (BCBP): 0%, 2% and 4%. CaCl 2 was not added into bamboo gypsum-bonded particle boards (BGBP). Mechanical and physical properties were evaluated and nondestructive testing was performed as well. The inhibition index of Guadua magna in the cement or gypsum setting was classified as "low inhibition". The addition of CaCl 2 at bamboo-cement boards increased the internal bonding and reduced the water absorption. Other properties were not significantly affected. The bamboocement boards presented higher bending strength and lower moisture content than bamboo-gypsum boards.

The paper aimed at evaluating the properties of plywood made from thermomechanically treated wood veneers. Veneers from Amescla (Trattinnickia burseraefolia) wood were treated in a hydraulic press with electric resistance heating. Two temperature levels were applied, 140°C and 180°C, for 1 and 2 minutes with 2.7 N/mm2of pressure. A total of 30 plywood boards were produced, including six boards produced from untreated veneers. The results showed that the thermomechanical treatment did not have any deleterious effect on glue line strength and most of the mechanical properties of plywood made from treated veneers were improved. On the other hand, plywood made from untreated veneers presented better dimensional stability. Dimensional stability properties were most affected by the temperature of the treatment, while mechanical stability, represented by the glue line shear strength, was positively affected by temperature and duration of the treatment.

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