Adesivos naturais e sintéticos em painéis compensados

Abstract

The aim of this study was to evaluate the properties of plywood panels produced with tannin adhesives from barbatimão e acacia and compare them with those with synthetic adhesives. The panels were manufactured with five crossed layers, the adhesive at a grammage of 360 g.m-2 (double line) and the assembly time of 10 minutes. We used a pressing cycle at a temperature of 150°C, specific pressure of 12 kgf.cm-2 and a time of 10 minutes. The panels produced with tannic adhesive from barbatimão as well as urea and phenol formaldehyde adhesives met the stipulated minimum for modulus of elasticity perpendicular, modulus of rupture parallel and perpendicular, the marketing standard, as met the minimum required by the European standard in relation to the shear strength. No statistical difference, in water absorption and thickness swelling was found after 24h immersion, among panels produced with urea-formaldehyde, phenol-formaldehyde and tannic barbatimão adhesives. The tannins from barbatimão had potential for production of plywood. However it is not recommended the use of tannic adhesive from acacia in outside places or internal place with high humidity