Influences of laser and plasma surface treatments on the primer paint adhesion for PPS/CF thermoplastic composite laminates

Abstract

For Poly(phenylene sulfide)/Carbon Fiber (PPS/CF) thermoplastic composite laminates, the main purpose of this study was to evaluate effects of “laser” and “plasma” surface treatments on the adhesion performance of primer painting by comparing with “untreated” and traditional “sandblasted” samples. For this purpose, after surface characterization of untreated and treated samples by Wettability, SEM, Surface Roughness, XPS and FTIR analyses; adhesion characteristics of an industrial primer paint applied onto PPS/CF surfaces were evaluated by using two different industrial methods: “Cross-cut Adhesion” tests and “Three-point Bending Adhesion” tests. Compared to the Untreated samples, it was observed that all surface treated samples could be assigned with the “best” primer adhesion grade of GT0. Moreover, surface treated samples had at least two times more maximum “Separation Load” with “cohesive” separation mechanism of primer paint layers. The success of the Sandblasted samples was due to efficient mechanical interlocking mechanism. For the Laser treated samples, adhesion performance was partly due to the mechanical interlocking and partly due to the chemical interactions; while for the Plasma treated samples it was mainly chemical bonding mechanism.