A powder coating gun is the primary instrument used in the process of powder coating, a surface finishing technique. It involves placing a dry paint polymer onto the object to be painted and curing the object until the paint sets. There are two distinct forms of powder coat material called thermosetting and thermoplastic, and different types of powder coating guns need to be used for each of these methods. Thermosetting powder coating guns have a few different ways of making sure the paint sticks to the substrate. Although these guns are relatively safe to use and do not pose much of a health risk, certain precautions still need to be taken to ensure the user’s safety.
All methods of powder coating operate around a single principle; users must apply dry paint to a substrate and bake it to make sure it sets. Powdering coating techniques, however, differ in what happens after the substrate and the dry paint coat are baked. Thermoplastic powder coats regain their original chemical composition when reheated whereas thermosetting powder coats are irreversibly cured. The thermoplastic powder coating technique requires that the substrate be lowered into a fluidized bed of dry paint powder, and the coating guns used in this technique are complex sprays that mix the dry powder and air into a chamber.
Thermosetting powder coating is the most popular form of this method mainly because the equipment and material required are usually easy to procure and relatively inexpensive. In thermosetting powder coating, the coating guns, which are typically hand-held, spray the dry paint powder onto the substrate. The substrate is then put into a paint oven at a temperature slightly above the dry powder’s melting point. Powder coating guns charge the powder so that it sticks to the substrate and stays there before it is cured. This electrostatic charge can be produced by friction, a technique that tribo-charged powder coating guns use, or by a high-voltage corona, a method used by corona-charged powder coating guns.
Powder coating is growing as a popular form of surface finishing not only because it is inexpensive, but also because it is considered environmentally safe for users as well. The dry powder used in powder coating contains virtually no volatile organic compounds, and the temperatures required for curing are so low that a regular household oven can produce them. Using powder coating guns does, however, produce a large amount of dust, so protective gear needs to be worn throughout the entire process. A fine-filtered mask in particular is a must-have when carrying out the powder application process.