One of the easiest – and most overlooked – ways to get the most out of your powder spray booth is to change your filters regularly. Clean filters keeps the booth air clear of particulate, making it easier to see what you are doing and prevents contamination from previous powder runs. On the other hand, clogged filters can cause powder to get everywhere – into the fan, into the other equipment and out into the shop. Unless you really enjoy expensive repair bills and cleaning literally everything in your facility, maintaining the filters is the way to go.
The first filter in many powder booths is a blanket filter. It sits right in front of the pocket or bag filters and is easily seen in most models. The blanket filter does not take long to change and when it’s dirty, it’s obvious – your filter will turn a dirty gray like dryer lint.
The blanket filter should be checked and cleaned every day. You can vacuum off the filter to extend the lifespan, but the filter can only be cleaned a couple times before it needs to be replaced. Do not used compressed air when cleaning out any part of the filtration system.
Don’t get in the habit of running with a filter that is worn out – you risk damaging the other filters and shortening the lifespan of your booth just by trying to save a couple dollars. Blanket filters are cheap; on-site repairs for all your equipment isn’t.
The second set of filters sit right behind the blanket filter and are called bag filters, cube filters or pocket filters. These filters last anywhere from 1-6 months, depending on how often you use the booth and how often you change the blanket filters.
TIP: The bag filters will end up holding several pounds of powder when you spray, which will warp the filter frame. To get the longest lifespan, empty and rotate the bag filters every three weeks.
You can further increase the bag filter lifespan by vacuuming out the bag filter once they are removed from the booth. Remember: DO NOT VACUUM OUT THE FILTERS INSIDE THE BOOTH. Do not for any reason use compressed air. You will perforate the filter and allow powder to go right into the HEPAs, quickly ruining them.
Finally, the HEPAs are the last filtration step before the air goes back into your shop. The HEPAs do not need to be changed very often – from 6 months in a constant throughput shop to 12 months with less use.
TIP: Check the HEPAs when you change the bag filters. You can remove excess powder by gently tapping the HEPA filter with the intake side pointed down against the floor.
Of the three filters, the HEPAs are the most expensive to change, which is another reason why changing the other filters regularly can save you quite a bit in the long run.