MECANIC PROPERTIES EVALUATION OF PLYWOOD PANELS OF Eucalyptus dunnii AND Eucalyptus dunnii/Pinus taeda

Abstract

The use of eucalyptus has been spreading out in Brazil and in several wood processing sectors. Apprehension related to lack of raw material in the south of Brazil makes eucalyptus an alternative for the substitution or use together with pine for making plywood panels. Thus, the aim of this paper was to evaluate the mechanical properties of two types of plywood panels: one that is produced with alternate plates of Eucalyptus dunnii and Pinus taeda (T1) and the other entirely with E. dunnii (T2). The results showed that the elasticity module (MOE) in T1 was inferior to T2, but with variance presenting higher value, indicating smaller stability of the tested material. This behavior was noticed in cutting directions, perpendicular and parallel. The module of rupture (MOR) showed similar values in both directions of cutting, but T1 showed higher variances only in the transversal direction. The resistance to cutting in the glue line in the treatment with cool water was similar in both treatments, with T2 presenting higher variance. On the same test 16% of the pieces of T1 came off during pre-treatment. When put to boil, T2 obtained better results, even though it presented a higher percentage of pieces coming off during pre-treatment.