Advanced Microanalysis Methods Solve Automotive Paint Adhesion Failures
Advanced Materials & Processes- February 6, 2012
During the early development of polymer-based automotive bumpers and fascia panels, many of the paint suppliers were faced with severe adhesion failures and very little insight as to the causes. Formulation adjustments by the paint manufacturers, a more thorough understanding of effects of molding parameters at the fabrication facilities, and better QA/QC practices at the automotive paint application stations have significantly reduced adhesion failures; however, adhesion failures are occasionally still encountered.
The typical paint system for polymer-based panels consists of a primer (to partially penetrate into the polymer surface), a colored basecoat, and a clear topcoat. Paint adhesion failure can take several forms, such as flaking, peeling and blistering, and can occur at the polymer interface or between paint layers (intercoat adhesion failure). Specialized analytical microscopy techniques are often required to identify and characterize paint deficiencies and foreign contamination to provide an explanation for the adhesion failure. Once the cause of adhesion failure is determined, appropriate corrective actions can be implemented.