Friction Induced Paint Damage: An Objective Assessment of Three Coating Systems

• Published in: SAE transactions 1998-01, Vol.107, p.570-575
• Main Authors: Ramamurthy, A. C., Szczepaniak, E., Mihora, D. J.
• Format: Article
• Language: English
• ISSN: 0096-736X; 2577-1531

Engineered injection molded thermoplastic polyolefins are now common substrates of choice for painted automotive bumper fascias. A major concern with painted plastics involves susceptibility to surface damage in the shop floor, during transit and in service life. Preliminary failure analysis of field specimens points out the damage in majority of the cases to be "cohesive", within the near surface regions of the substrate. This paper describes the application of a second-generation computer controlled instrumentation, which simulates Friction Induced Damage (FID) similar to those observed in the field. It has been recognized in several earlier works, that FID is a complex phenomenon and is a function of number of tribological and environmental variables. Since the material systems are viscoelastic, FID is also a strong function of temperature and the dynamic mechanical properties of the coating and substrate. This paper forms a part of a larger program, which involves the development of Key Life Tests to simulate FID phenomenon. In this paper we examine the role of two commercial and an experimental olefinic paint system on FID performance.