Cleaning Processing Racks
What is the best process for cleaning processing racks and how often should they be cleaned?
Q. What is the best process to clean processing racks? (Burn-off, chemical or bead blasting?) How often should racks be cleaned? –T.R.
A. All methods can be effective to clean and strip your processing racks. The stripping frequency of the racks will be dependent on how they are used. If you are employing a paint process that requires good grounding, you will need to clean racks more frequently than a shop that is not dependent on good grounding to achieve high transfer efficiency. In the end, you will want to clean racks frequently enough that you do not experience any significant reduction in transfer efficiency, since that will be much more costly that the inconvenience of having to clean the racks again.
The four major considerations regarding process selection are environmental considerations, labor, energy and capital costs.
Capital: The burn-off oven would have the greatest cost with bead blasting, then chemical cleaning further behind.
Environmental: Chemical stripping is often the least environmentally friendly, followed by burn-off and bead blasting possibly tied.
Labor: Bead blasting would likely have the highest labor content, followed by chemical stripping and burn-off at a close tie.
Energy: The burn-off oven, operating typically around 900°F would be the most energy intensive. Stripping tanks are typically run quite hot, so they would have the second highest energy usage, followed by bead blasting that would likely just require energy from a compressor.
The size of your operation and other existing infrastructure will drive your final decision once you have taken the above factors into account.
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