Corona Powder Coating Gun vs Tribo Powder Coating Gun

Both tribo and corona powder coating guns are commonly used for particle charging in the powder coating industry. Depending on the application, tribo or corona powder coating technologies have a lot of advantages and disadvantages.

What is corona powder coating?

Corona powder coating is applying high voltage to charge the powder particles and creates an electric field. those particles with negative charge will be easily attracted to a grounded or positive-charge work piece.

What is tribo powder coating?

Tribo powder coating process is using triboelectric effect that produced during the close friction between material of gun barrel and powder to charge the powder particles.

Corona Powder Coating Guns

Advantages

1) Built in high voltage  (normally 100kv) cascade generates strong electrostatic field results in rapid charging and deposition

2) Electrostatic fieldlines support the powder particles to move towards the work piece, powder coatig operation is more easiler

3) Light, robust spray gun, simple construction with less wearing parts.

5) Accepts different types of powder materials and particle sizes

6) Film thickness can be simply changed by voltage variations

7) Spray gun design are easy to clean that suits for fast colour changes

Disadvantages

1) Strong fieldlines lead to Faraday Cage effect, complex shapes with deep corners is hard to get a perfect coverage if not using a professional advanced powder gun.

2) Orangle peel, back-ionisation, multiple coats are challengings for corona powder coating guns.

Tribo Powder Coating Guns:

Advantages

1) Avoids Faraday effect, better peneration of deep corners, recesses, holes

2) Powder can be better directed by the use of directional finger sprayers and aerodynamics

3) Thicker film builds possible without back-ionisation

4) Uniform coating, no orange peel effect

5) Higher productivity by closer arrangement of objects

Disadvantages

1) Charging particles takes more time, thus production efficiency decreases during long runs.

2) More complicated structure, color changes take a long time

3) Higher initial investment cost of spray gun for equal capacity output

4) More wear and shorter life time of gun parts such as spray nozzles, venturi sleeves.

5) Higher requirements of compressed air wirh good cleanliness and humidity

6) Requires comprehensive training of the application operator