ABSTRACT The objective of this study was to determine the adhesion quality of Pinus sp. wood glued joints by means of tensile strength, shear strength before and after exposure to weathering simulated conditions, and delamination tests. Wood glued joints were bonded with three adhesives: resorcinol, resorcinol-tannin (90:10) and resorcinol-tannin (80:20) at 25 and 60 °C with 0 and 10% methanol contents. Treatments presented restriction for tensile strength. All adhesives showed good results at 25 °C. The resorcinol-tannin (90:10) adhesive lost strength at 60 °C. Methanol improved the adhesion quality for all adhesives at 60 °C.

RESUMO O objetivo deste estudo foi avaliar a qualidade e a resistência de juntas de madeira de Pinus sp. coladas através de testes de tração, cisalhamento antes e após condições simuladas de serviço externo e testes de delaminação. As juntas foram coladas com três adesivos: resorcinol, resorcinol-tanino (90:10) e resorcinol-tanino (80:20) a temperaturas de 25 e 60 °C, com 0 e 10% de metanol. Os tratamentos apresentaram restrições quanto à tração normal. A colagem a 25 °C apresentou bons resultados para todos os adesivos. A colagem a 60 °C diminuiu a resistência do adesivo resorcinol-tanino (90:10). O metanol melhorou a qualidade de adesão de todos os adesivos a 60 °C.

Abstract The objective of this study was to determine the adhesion quality of quaruba cedar wood glued joints by means of tensile strength, shear strength before and after exposure to weathering simulated conditions, and delamination tests. Wood glued joints were bonded with three adhesives: resorcinol, resorcinol-tannin (90:10) and resorcinol-tannin (80:20) at 25 and 600C curing temperatures with 0 and 10 % methanol contents. Wood glued joints bonded with resorcinol adhesive at 250C without methanol presented high tensile strength, with values similar to solid wood. Wood glued joints bonded at 250C presented the highest shear strength values even after the exposition to weathering simulated conditions.

Abstract A factor of great importance for the quality of the adhesive line for external services is the environmental exposition. Wood of eucalyptus citriodora (Corymbia citriodora) was used glued with three types of adhesives: pure resorcinol, resorcinol 85% and tannin 15% and resorcinol 85% and phenol 15%; in 30° and 60°C and with and without methanol (15%). The test of shear strength was made without and with exposure conditions according to instruction ASTM D-1183. The adhesive resorcinol-tannin in almost all conditions were as resistant as the pure resorcinol, the resorcinol-phenol was resistant as much a the pure resorcinol in the collage without methanol at 60°C.

Resumo Um fator de grande importância para a qualidade da linha adesiva para serviços externos é a influência do intemperismo. Para os testes foi usada a madeira de eucalipto citriodora (Corymbia citriodora), colada com três misturas adesivas, resorcinol puro, 85% resorcinol e 15% tanino e 85% resorcinol e 15% fenol; nas temperaturas 30° e 60°C e com 15% de metanol e 0% de metanol. Foi realizado o teste de cisalhamento paralelo às fibras sem e com exposição ao intemperismo, segundo norma da ASTM D-1183. O adesivo resorcinol-tanino em quase todas as condições foi tão resistente quanto o resorcinol puro, o resorcinolfenol foi resistente ao intemperismo tanto quanto o resorcinol puro, apenas na colagem sem metanol na temperatura de 60°C.