Powder coatings are one of the easiest ways to protect equipment and other objects. Coating that is applied as a powder starts out free-flowing, and it doesn’t contain solvents because it doesn’t need a binder in order to stay in liquid form. Sometimes a powder coating just makes more sense than a liquid paint coating.
For example, powder emits almost no volatile organic compounds, so it provides a safer indoor environment. Also a powder coating tends to be thicker than a liquid coating, and any overspray that’s left after coating an object can be reused, making it more economical than a liquid coating.
So how does the application of powder coatings actually work? First it’s important to understand that there are two categories of powder coatings: thermoplastic and thermoset. The thermoplastic kind doesn’t change at all when it bakes on, but the thermosetting kind reacts with other groups of chemicals in the powder so that its performance is enhanced.
Before the coating can be applied, it must be produced. In order to do so, the engineering company mixes polymer granules with some kind of hardener, as well as other ingredients and pigments. Then the mixture gets heated up inside an extruder before it’s rolled out, cooled, and then broken up. The chips are then milled and sieved so that they turn into a very fine powder that’s ready to be sprayed onto a surface.
Next there are three steps involved in actually applying the powder:
- First the part must be prepared. It must be thoroughly cleaned so that the powder coating will stick smoothly to it. There are both mechanical and chemical ways to prepare the part. Which method is used depends entirely on the type of part it is, its size, and what type of material it is made of.
- Second, the powder is actually applied to the part. Powder is applied to most metal objects by spraying it on with an electrostatic gun. The gun gives the powder a negative electric charge, and the object is grounded. In other cases, the powder is sprayed using compressed air. There are many different nozzles that can be used, depending on the type, shape, and size of the object that is being coated in powder.
- And finally, it is cured by being baked in an oven. The curing process in powder coating is known as crosslinking, and depending on the type of coating that is being used, it requires a specific temperature and a specific amount of time in the heat in order to reach full cure and create the properties it was designed to offer. Most powders cure around 390 degrees Fahrenheit on a 10-minute timer, however that schedule could change according to the needs and requirements of the manufacturer.
It’s important to have a certified and reputable applicator take care of all your powder coatings to ensure that they are applied correctly. For the highest quality application of powder coatings, let the experts at Toefco Engineered Coating Systems help you out. We are the coating customizers because we specialize in engineering coatings so that they will precisely fit the needs of our customers.
We offer a wide variety of different types of coatings and use the highest quality automated equipment so that any business owner can afford superior powder coatings. We are ISO 9001 Certified, and we offer Teflon™, Excalibur, Xylan, Fluoropolymer, Molybdenum disulfide, epoxy thermal cure, high heat paint, PTFE, and all the other most popular types of coatings.