Quality of plywoods obtained from melia azedarach combined with pinus taeda, produced with urea-formaldehyde and phenol-formaldehyde resins

Abstract

This study was developed to evaluate the quality of plywood produced from Melia azedarach in combination with Pinus taeda, glued with urea-formaldehyde resin (UF) and phenol formaldehyde (PF). Panels were produced using five veneers of Melia azedarach only, five veneers of Pinus taeda and also with faces made of Melia azedarach and core with Pinus taeda. The panels were evaluated by glue line shear tests and by static bending in parallel and perpendicular directions. The higher contents of extractives in Melia azedarach wood did not reduce the glue line shear strength between the layers. For both UF and PF glues, panels produced with veneers of Melia azedarach showed better results on static bending and glue line shear tests. The results indicate great potential of Melia azedarach wood in plywood production, both for internal use (UF), and for external use (PF).