Q: We have a dedicated/automated powder line. The parts go through the wash stages and are powdered in an enclosed area. Powder guns are oriented from both the top and bottom. We have a problem where powder collects on the top inside of the booth and eventually falls in clumps on the product.
We have a regular cleaning schedule for the booth, but it is cumbersome and takes too much time. Do you know of any way to prevent the powder from collecting in the first place, or any other suggestions that would make this more efficient? I would appreciate any time you could spare to consider this.
A: Sounds like a very aggravating problem. I think that you need to explore a combination of design, process, and materials to tackle the problem.
Design
I would consider replacing flat surfaces (if you have them) with curved ones. The curved surface will allow for better air flow and a potentially cleaner surface.
Check also the air flow of your system near the top of your booth. Is there a dead space? Can your airflow be redirected to pull air from this area?
Process
Do you have an adequate ground for your parts? Powder is electrostatically attracted to the closest and best ground. If your booth ceiling is conductive and well-grounded, then the powder will be preferentially attracted to this surface.
Is your spray gun orientation and pattern too wide? Are you overshooting the top parts on your hangers and thereby spraying powder too high? Do your guns trigger too soon before seeing parts and stay on too long after the hanger has passed? Again, powder will look for a ground, which will most probably be your booth walls and ceiling.
Materials
Is the top of your booth comprised of metal or a lesser-conductive plastic? Metal will attract powder much better than polypropylene or HDPE. A quick fix may involve installing an intermediate plastic baffle between your parts conveyor and the booth ceiling.
I hope that these ideas will help you in your quest to eliminate this problem.