Advantages
1) Strong electrostatic field results in rapid charging and deposition
2) Electrostatic fieldlines support the powder particles to move towards the work piece
3) Simple repairs of the powdered surface are possible
4) Light, robust spray gun
5) Accepts different types of powder materials and particle sizes
6) Film thickness can be simply changed by voltage variations
7) Simple construction is suited for fast colour changes
Disadvantages
1) Redundant ions generate a self-limiting effect
2) Strong fieldlines lead to Faraday effect (irregular coating, corners and crevices are not properly covered)
3) These effects can be reduced or eliminated respectively by voltage changes or use of anti-ionisation rings (to reduce Faraday and Orange peel effect)
Advantages
1) No Faraday effect; deep crevices, corners and hollow spaces can be better penetrated
2) Powder can be better directed by the use of directional finger sprayers and aerodynamics
3) Less, if any, fat edges on the coated surface
4) Uniform coating
5) Very good automation possibilities
6) No high voltage generator required
7) Higher film builds possible without back-ionisation
8) Higher productivity by closer arrangement of objects
9) Better flow; practically no orange peel effect
Disadvantages
1) Performance is strongly influenced by uncontrolled air-streams
2) Special powder is necessary; formulation must be adapted to the Tribo charging process
3) Particles smaller than 10 microns are difficult to charge
4) Powder deposition slower than for corona
5) Colour changes take a long time
6) Charging of particles takes more time and efficiency reduces during long runs
7) Higher gun investment cost for equal capacity output
8) More wear and so shorter life time of gun internals and other parts such as powder pump venturi inserts
9) More precise specifications for the cleanliness and humidity of the compressed air
10) Comprehensive training of the application personnel is recommended
