Development of an Enhanced Accelerated Weathering Test Cycle for Automotive Coatings 2012-01-1173

Laboratory accelerated weathering test methods, such as SAE J2527 and JIS D 0205, are used to predict long term durability in the development and approval of automotive coatings. However, recent studies have shown that these methods are deficient with respect to spectral match to sunlight, simulation of water, and temperature profile. These deficiencies can limit the confidence of the laboratory accelerated test, and as a result the user needs to rely more heavily on long term natural exposure results. To increase the confidence of laboratory accelerated weathering testing, a new xenon arc light source filter and test protocol were investigated. Through a combination of natural weathering studies and prototype method testing, an improved accelerated weathering test cycle has been developed. The key characteristics of the improved method include the application of a new light source filter for spectral match to sunlight in the UV spectrum and an optimized water spray cycle that can create realistic moisture related coating damage. This new method has enabled improved laboratory accelerated weathering test confidence while reducing the total accelerated weathering test time.