Analysis of Wood Bonding Failures that Initiated Before Adhesive Solidification: Air Fingers and Cavitation

Abstract Bond line openings while an adhesive is still viscous (liquid or paste-like) leave characteristic marks. Air fingers and cavitation develop on the surface of when joint parts are fully partially separated before solidifying adhesive. Therefore, observation air provides important clues root cause failure bond lines. There limited knowledge about factors that lead to formation either cavitation. Additionally, a resoftening thermoplastic adhesives by high temperatures may be confused with developed initial curing. To improve understanding structures, we assemble some experiments this phenomenon. dominate easily penetrates adhesive, thickness high, has low viscosity (early in process). Cavitation dominates layer thin, (late process) ingress restricted.