Operators judge fluidization by eye. Powder that boils evenly across the surface is ready to pump; geysers, craters or a still, packed surface mean the air is wrong, the membrane is blocked or the powder is damp or full of fines. The goal is a light, steady simmer, not a violent boil that throws powder into the room.
Heard on the job
Hopper's barely boiling on the left side, membrane is probably blinded with fines.
Also heard as
- simmer
Related terms
Feed hopper
The fluidized container that holds powder and supplies it to the gun pumps.
Fines
The smallest particles in a powder, roughly under 10 microns, which fluidize, charge and recycle poorly.
Spitting
Powder bursting out of the gun in clumps, leaving lumps and heavy spots on the part.
Reclaim
Oversprayed powder collected from the booth and fed back into the system for reuse.