Physico-mechanical properties of oriented strand boards of Eucalyptus grandis and Cupressus glauca

The objective of this research was to evaluate the technical feasibility of the use of Eucalyptus grandis W. Hill ex Maiden and Cupressus glauca Lam. wood to manufacture oriented strand boards (OSB). Boards of three layers with the ratio of 1:2:1 were bonded with 5% and 8% of urea- (UF) and phenol-formaldehyde (FF) resins, based on dry weight of particles and with an apparent nominal specific density of 0.75 g/cm(3). As for eucalyptus OSB boards, they presented mechanical properties above the value required by the standard CSA O437.0, class O-2, except for the rupture modulus, parallel alignment, bonded with urea-formaldehyde adhesive. All mechanical properties of cypress boards were higher than Eucalyptus boards and also higher than Canadian standards requirements. All the boards presented low dimensional stability and after 24h swelling in water immersion, were not up to the Canadian norms CSA 047, class O-2. Among all treatments studied, 8% FF presented the best performance. Eucalyptus and cypress woods have shown to be a feasible alternative as raw material for OSB panels manufacturing.