Understanding, Optimizing, Measuring Water in Xenon-Arc Accelerated Weathering for Automotive Exterior Coatings

摘要

Continual demands from consumers for highly durable coatings with excellent appearance motivates automotive manufacturers and paint suppliers to introduce new coating systems into the marketplace to meet those demands. Typically, automotive manufacturers require up to five years of Florida exposure for a new paint system before they will implement the new technology. Additionally, accelerated weathering is used to provisionally approve new technologies while simultaneously monitoring the ongoing performance of technologies used in production.rnThe current commonly accepted state-of-the-art in xenon arch accelerated weathering is SAE J2527 (based on the obsolete J1960). Over the years, it has been well documented that J2527 does not adequately predict field failures observed from Florida results.rnTo improve correlation between outdoor Florida results and accelerated lab weathering results and extensive research project has been undertaken to develop a new test procedure. In the cores of the research, all of the critical factors related to coatings failures are being explored.rnThis paper details the experiments undertaken to better understand and characterize moisture in the service environment. Additionally, it reports on the moisture delivery systems of current xenon arc accelerated weathering equipment. Specifically, ii discusses water volume and uniformity. Also detailed are the experiments and conclusions on how to reproduce the moisture observed in outdoor weathering in xenon arc accelerated weathering devices. Additionally, it reports on work recently completed to better match the solar spectrum. Concluding with the steps being undertaken to conclude the development and produce a better accelerated.