Resistência ao cisalhamento de painéis compensados produzidos com adesivo à base de taninos de Stryphnodendron adstringens (barbatimão)

Abstract

The purpose of this research was toevaluate the shear strength of plywood panels produced with tannin adhesives obtained from the leaves and bark of the species Stryphnodendron adstringens (barbatiman). To this end, panels were produced with veneers of Araucaria angustifólia and tannin adhesive from the leave sand bark of barbatiman, tannin from the bark of black acacia (Acacia mearnsii), commercial phenol-formaldehyde adhesive, and mixtures of different types of tannins. For each treatment, six panels with five plies and adhesives in 320 g/m² ratio in double glue line were produced. The adhesive from the bark of barbatiman showed the same shear strengthofthe comercial adhesive from the tannin bark of black acacia, but with less strength than the panels produced with phenol-formaldehyde adhesive. The tannin adhesive from the leaves of barbatiman is feasible of application only in combination with others types of tannins.