Ant-Nest Corrosion in Copper Pipes Triggered by Ethylene Vinyl Acetate-Based Adhesive

Abstract

Corrosion of condenser circuits in refrigeration systems significantly impacts appliance reliability and longevity. This study investigates an unreported cause linked to changing adhesive materials during copper pipe assembly. Transitioning from a polyethylene-based adhesive to one containing ethylene vinyl acetate caused unexpected perforation of copper coils within months. We hypothesized that even trace amounts of acetic acid, a byproduct of the latter adhesive, trigger a peculiar localized morphology known as “ant-nest corrosion.” We propose using ethylene vinyl acetate-free adhesives to prevent this issue in refrigeration systems.