Selecting a Powder Coating Gun (Tribo vs Corona Style)

If you are just getting into powder coating products one of the key initial equipment investments you will make is the powder coating gun. Additional common equipment, which we will cover in future posts, include a powder booth, and any powder coating recovery equipment (if you plan on doing a higher volume of powder coating). This article will cover the two most common types of powder coating guns and the benefits as well as draw backs of each.

Corona Style Powder Coating

Corona style powder coating guns charge the powder coating as the powder leaves the nozzle and passes through an electric field that is created by an electrode that’s part of a corona powder coating gun. The charge (which is usually negative) is attracted to a grounded product which allows the powder to attach to the products surface.

The Major Benefits of Corona Style Powder Coating

With a corona style powder coating gun there are not parts that are exposed to the powder other than the powder nozzle. Without having any parts exposed to wear, the corona powder gun will hold up longer.  A Corona style powder gun is also compatible with the widest variety of powders including effect powder coatings.

The Major Limitations of Corona Powder Coating Guns

The major limitation to a Corona Powder Coating Gun is that it can have problems with the far a day cage effect. What this means practically is that a Corona Powder coating gun will not always work well on product surfaces that have a lot of recessed corners and similar challenges. While there are ways to help reduce these issues like using a high quality powder coating that retains the electrostatic charge from the powder gun well, often times if you are not getting the coverage you want with a corona style powder coating gun you can consider a tribo style.

Tribo Style Powder Coating Guns

Tribo powder coating guns are less frequently used in comparison to Corona Style. This is due to a variety of factors. A tribo powder coating gun is different than a corona powder coating gun because a charge is created when it rubs against an insulator or conductor within the powder coating gun. Most commonly the charge is a positive charge as the component in the tribo gun usually removes electrons which are quickly discharged through the gun.

The major benefits of Tribo Powder Coating Guns

A tribo powder coating gun charges powder by stripping electrons creating a positively charged powder. With a tribo style gun there is no actual electrostatic field which reduces the issues with far a day cage effect. This allows a tribo powder coating gun to coat in thinner coats and in recessed areas with greater ease than a corona powder coating gun. If your target has a lot of recessed areas, fins, or similar strucutres the tribo powder coating gun can be the perfect solution for your powder needs. Additionally tribo powder coating guns can apply thicker powder coats, they also tend to provide a smoother finish especially with thicker coats. Tribo guns effectiveness at applying thicker coats is due to not passing the powder through a charged field which provides unique characteristics that allow for better application of thicker mil builds.

The major disadvantages of Tribo Powder Coating Guns

There are a few disadvantages to a tribo powder coating gun. First, because powder moves over the charging conductor or insulator these components can wear resulting in greater frequency of equipment breakdown. Additionally, the tribo style powder gun will not powder coat as quickly as a corona style powder gun. The slower production of a tribo powder gun is because the powder must be able to remain in the gun for a sufficient length of time to allow for electron exchange to occur which with higher powder volumes (higher production rates) the powder would move to rapidly through the gun and not provide sufficient time for the electron exchange to occur. This lower powder output can also mean that  more tribo powder coating guns would be needed compared to corona style powder guns in a powder line to coat the same volume or products due to tribo guns lower output. Finally, since tribo powder coating guns rely on transferring of electronics they have more limitations to the types of powder coating they can effectively apply.

Summarizing

• If you powder coat intricate parts with a lot of corners, recessed areas, or similar situations tribo may be right for your application (assuming your powder will work with a tribo gun)
• If you need a smooth finish and thicker mil builds of powder coating a tribo powder coating gun could be the best solution for you
• For the majority of powder applications and for higher production corona powder coating guns will be the more usual choice