Wrinkle powder coatings generally require more heat for curing than other powder finishes. It has to do with the chemical reactions required to create the wrinkle look and they like a shock of high heat in order to get things going.

So you're air cleaner will see heat in the 400 degree range for up to 20-25 minutes.

Because of this I've tried to steer customers away from powder coating any assembly with dampers, diaphrams, etc. unless the parts can be removed. If the parts don't melt they may end up very brittle and fail quickly once in use.