Powder coating is one of the most popular industrial finishes available. It offers superior protection and lasting beauty, and it is more environmentally-friendly than many other finishes. Powder coated products can be found across industries, including automotive, agricultural, sporting goods, outdoor equipment, and manufacturing applications, only to name a few. In this guide, we’ll take a look at some of the common questions about powder coating, providing details on why this finishing method has many advantages over wet painting.
What is Powder Coating?
Powder coating is the process of applying a dry powdered pigment to a product, then curing it in a hot oven to fuse the powder particles into one cohesive finish layer. Powder coaters use a combination of air pressure and both positive and negative electrical charges to coat an item evenly. Once the coated item is cured, the finish is incredibly durable and resistant to fingerprints, chemicals, and environmental exposure.
What is the Powder Made From?
The powder used in powder coating is comprised of dry pigments and resins that are cured by heat. The resins take several different forms, but typically fall into three major categories: polyesters, epoxies, and hybrids. Polyester resin/pigment powders are often used on products that will be exposed to the elements, and are particularly resistant to UV exposure and moisture. Epoxy resins offer superior corrosion resistance, especially from industrial chemicals and oils. Hybrids combine the best attributes of polyesters and epoxies, resulting in a tough, attractive finish that performs beautifully.
The pigment powders are available in a rainbow of pre-mixed colors. Experienced powder coating services can also custom-formulate resins and pigments to match specific trade dress colors or to meet exacting needs like thickness level, edge coverage, and flexibility. The powders come in metallic and different glosses; a matte finish is one of the most common gloss levels in industrial applications, but high-gloss and satin finishes are also possible with this finishing method.
How is Powder Coating Performed?
There are several steps involved in coating an item with a powder coated finish. First, the parts to be coated are pre-treated to remove debris, dust, and contaminants from every surface. This may require chemical dipping, sandblasting, or hand-sanding in certain applications.
Next, the part to be coated is given a negative electrical charge. The powder coating “gun” – the tool that distributes the powdered pigment – charges the powder with a positive electrical charge as it exits the tool’s nozzle. These charges help the powder to adhere evenly to every surface of the item being coated. By adjusting air pressure and charge, the powder coater can alter the coating thickness, achieving the perfect finish for any application.
Finally, once the parts have been coated with the powder, they take a trip through a curing oven. Here, curing can be adjusted both in time and in temperature, causing the powder to flow and fusing it into a glass-like surface on the items being coated. The end result is an attractive finish that can withstand years of use and exposure while retaining its appearance.
What Can be Powder Coated?
Powder coating finishing methods are typically used on metal substrates, including steel, aluminum, and metals with zinc coatings. Because the finishing process uses electrical charges, the item to be finished generally has to be able to conduct electricity. Despite this, advanced methods are being developed, allowing certain non-metallic items like MDF (medium-density fiberboard) and even some plastics to be coated.
An experienced powder coating service can help you determine the best finishing method for your specific application. With the range of colors and glosses available, powder coating can enhance the look and performance of your products, giving items lasting durability and corrosion resistance.