Propriedades físico-mecânicas de chapas aglomeradas produzidas com bambu, pinus e eucalipto.

Abstract

This study investigated the physical and mechanical properties of particleboards formed of bamboo (Bambusa tuldoides), pine (Pinus taeda) and eucalyptus (Eucalyptus grandis) and their combinations. To this end, panels were made, defined by the use of each type of particle pure or mixed by two or three being set 0, 25, 50, 75 and 100% of dry weight proportion, totalling 36 panels. The physical tests performed were the moisture content, density, water absorption and thickness swelling and the mechanical were static bending, screw withdrawal and internal bond. In order to complement the study, non-destructive testing were performed by direct and indirect ultrasonic to obtain models relating destructive and nondestructive methods. The results were analysed by for simple correlation and regression. In general, homogeneous panels made of pine and eucalypt showed better results than pure bamboo. The inclusion of bamboo particles decreased, mainly, the mechanical properties of the panels. All particleboard were below the minimum standards in physical and mechanical tests, only internal bond in panels pure pinehad higher values than commercial standards. Treatments using a combination of all species were compared, graphically, and resulted in lower than homogeneous panels of bamboo, for water absorption after two and twenty four hours and swelling after two hours. However, showed superior performance in swelling in thickness after twenty four hours, modulus of rupture and modulus of elasticity in static bending, screw withdrawal and internal bond. The non-destructive direct method showed better correlations than the indirect one. The significant correlations of the direct dynamic modulus of elasticity, in order of significance, occurred with board density, screw withdrawal, and static modulus of rupture and modulus of elasticity.