Adhesion performance of melamine-urea–formaldehyde joints of copper azole-treated Eucalyptus grandis at varied bonding process conditions

Abstract The effect of copper azole impregnation, wood density, adhesive spread rate, mechanical pre-treatment, open and close assembly times, bonding pressure, and press duration on melamine-urea–formaldehyde-bond performance of Eucalyptus grandis joints was investigated. The results obtained showed that the shear strength was mainly affected by copper azole concentration and bonding pressure while wood failure and delamination were mainly affected by wood density, copper azole concentration, and mechanical pre-treatment. With the adaptation of bonding parameters, results suggest that satisfactory improvement of melamine-urea–formaldehyde-bond performance in copper azole-treated E. grandis laminates is feasible. This will make the production of treated hardwood laminated composites for structural applications in tropical and sub-tropical regions attainable.