Statistical modeling of coating lifetimes in disparate environments

The effect of environmental loads on the propensity for failure of automotive coating systems was evaluated for both the United States and China. Population weighted climate distribution functions were created for both nations and applied to various failure modes including yellowing or color change, gloss loss, delamination, and cracking. The effect of process variability on specific failure modes was captured through the use of minimum and maximum film builds measured on vehicles produced in a commercial automotive assembly plant. The U.S. was shown to be a significantly harsher environment for most failure modes driven by UV radiation and high temperatures. China was shown to be a harsher environment for failure modes driven by liquid water and cold temperatures. The use of these models allowed for the prediction of regional failure rates given the time to failure of a coating of known thickness in a different location.