Powder sliding through a PTFE barrel picks up a positive charge by friction. With no electrode there are almost no free ions, so tribo guns penetrate recesses and corners far better than corona guns and resist back ionization at heavy builds. They need tribo-grade powder, more air, a steady humidity and more maintenance, and they deposit powder more slowly on flat work.
Grab the tribo gun for the wire baskets, the corona just keeps piling it on the outside wires.
Tribo guns charge poorly when shop humidity climbs, so many tribo users run dehumidified compressed air and watch the charge meter.
Also heard as
- tribo
- triboelectric gun
- friction gun
Related terms
Corona gun
A powder gun that charges particles with a high-voltage electrode at the tip, the most common gun type.
Faraday cage effect
The tendency of charged powder to avoid inside corners and recesses because the electric field bunches on nearby edges.
Free ions
Charged air molecules from a corona electrode that never attach to powder but still land on the part.
Back ionization
Tiny electrical discharges inside an overcharged powder layer that repel new powder and pit the finish.