More factors when deciding between spray guns

There are other factors that you must also consider when deciding between the Tribo and the Corona spray gun, including part geometry, part material, coating appearance, coating thickness, composition, color change, etc.

Part Geometry: Tribo-charging guns can efficiently coat a wide assortment of part shapes. However, because a Tribo gun doesn't have a strong electric field between the gun and the object being coated it virtually eliminates the problem of ?faraday cage effect.? The particles flow into recesses and difficult to reach areas by nozzle directions and airflow. With the use of the wide variety of spray head and nozzle combinations available, a Tribo gun can provide exceptional control of the amount, direction, and velocity of powder sprayed. In addition, this results in countless parts being coated automatically without the use of a manual touch-up gun. Tribo guns can be used to coat condensers, transformers, bicycle or motorcycle frames, wire baskets, folding chairs and others. Part Material: The Tribo-charging gun has the ability to coat a few parts that are not highly electrically conductive because it does not deposit a large amount of free ions on a part as the corona gun. However, with the Tribo-charging gun, these parts still must be electrically grounded. Therefore, it is necessary to perform spray trials on non-metallic products that are close as possible to the actual non-metallic product being coated.

Appearance of Coating: The appearance of the powder coating on a part can be affected by many variables, including how well the equipment is maintained. For this reason it is vital that both routine and periodic maintenance be performed. However, many believe that the Tribo gun produced a more smoother and blemish-free appearance with no ?fatty edges.

Coating Thickness: Corona guns are excellent at applying thin films onto parts. However, as coating thickness increases, charge can build up on a part, which can build up on a part and repel incoming powder particles, thus limiting the coating thickness. Tribo guns, on the other hand however, are better for applying thick films because they produce few free ions. With a Tribo gun it is possible to acquire a film build up of several hundred microns on an unheated part with a single pass.

Coating Composition: Corona spray guns can use practically any composition of powder coatings. Tribo spray guns on the other hand are much more dependent on the correct powder composition particle the grind size and the surface of the powder particles. Therefore, it is vital that all powders be tested in Tribo equipment to guarantee excellent results. For metallic coatings, corona guns are usually used.

Color Change The area of the object that is contacted with the powder may be greater in a Tribo gun than with that of a corona gun. Therefore, color change can take longer with a Tribo gun because of the larger surface that requires cleaning.

Conclusion: Clearly, the decision between Tribo and corona equipment is not an easy one. Each type of gun has its place in the industry depending on the application. Both the Tribo gun and the Corona must be considered for their specific designs and overall chargeability. It is also important to remember that the powder spray gun is only one piece of equipment in the powder coating process.