Effect of copper azole preservative on the laminate’s surface wettability and interlaminar shear performance of preservative treated Glulam

Abstract

Abstract Copper azole (CA) preservative applied to glulam improves the durability of glulam. The purpose of this study is to evaluate the effect of CA preservative on the surface bonding quality of laminates under different surface conditions. Surface morphology and wettability of CA preservative treated laminate were investigated. A comparison was also made of interlaminar shear performance obtained from preservative treated glulam under different environmental conditions. The results indicate that CA preservative adheres to wood fibers and occupies part of wood voids, which has a significant adverse effect on water permeability of preservative treated laminate. Planing can effectively improve the surface wettability of preservative treated laminate. CA preservative tiny particles on the planed laminate surface are distributed relatively uniformly, and the proportion is smaller than that of the unplaned laminate. The interlaminar shear strength of preservative treated glulam made of planed laminates is at least 15% higher than that of the glulam made of unplaned laminates. No matter in hot and humidity environment or natural aging tests, preservative treated glulam glued by resorcinol formaldehyde (RF) adhesive performed better than that by polyurethane (PUR) adhesive. It is recommended that in order to obtain a reliable preservative treated glulam quality, the 0.6mm planing of laminate and RF adhesive are required.