Weathering Performance Advantages of Mold-In-Color Acrylic Versus Coated Plastics for Exterior Trim Applications

This paper will explore the actual outdoor weathering performance of multiple plastic technologies used for exterior trim including various approaches to coatings and the use of molded in color acrylic. For each technology, actual 5-year old parts were obtained and then photographed along side new parts to visualize change in appearance. Next the specimens are analyzed for change in color and gloss. Finally the parts are analyzed for surface chemistry changes via infrared spectroscopy.

Changes in surface chemistry and appearance after weathering are associated with the chemical nature of each polymer. While the weatherable mold-in-color PMMA does not change, it is concluded that many of the coating technologies used to protect plastics that are not weatherable deteriorate after 5 years of outdoor usage and that degradation of the plastic still occurs.