Plywoods of northeast Argentinian woods and soybean protein based adhesives

NICOLAO, ERIKA S.; CIANNAMEA, E. M.; P.M.STEFANI

Conferencia; Forest Products Society International Conference; 2021

Forest Products Society

Plywoods were manufactured using pine (Pinus taeda) and eucalyptus (Eucalyptus grandis) northeast Argentinian woods. A formaldehyde-free bio-based adhesive, based on chemical modified soy concentrate protein was used for assembly three layer plywoods. In this work we focused on the relationship between bonding quality parameters of the plywoods and the morphology of the glued line.   Wood characteristics such as contact angle, roughness, density and moisture content were measured previously to plywood assembly. Bonding quality parameters (percentage of wood failure and shear strength) of the plywood were measured and the results were related with the microscopic observations of the glue joint. Broken tracheids along the bond line in pine enhanced poor bonding strength between the veneers, giving lower wood failure percentage values, while the presence of vessels in the eucalyptus acted as weak links determining the path of propagation of the fracture through the central veneer. In spite of the differences, both species combined with soybean protein adhesives were suitable for plywood interior condition applications.