From washing machines and clothes dryers to automobiles, handrails, fences and more, countless products are manufactured with a powder-coated surface. This finishing process involves the application of dry powder onto the surface of products or materials. Powder coating has been around for more than half a century, with origins dating back to the 1960s. Since then, it’s become an increasingly popular finishing process used by manufacturers.
The Basics of Powder Coating and How It Works
When a product is powder coated, it’s sprayed with pressurized dry powder that sticks to the product’s surface. Rather than using a conventional spray application, though, manufacturers use a special technique known as electrostatic spray deposition (ESD). This method leverages the properties of static electricity to make the powder stick to the surface to which it’s applied. It’s not uncommon for manufacturers to powder coat flat, smooth metal surfaces. Using ESD, manufacturers don’t have to worry about the powder dripping or falling off smooth surfaces such as this. This method encourages the powder to stick by creating an opposite electrical charge.
After applying the powder via ESD, manufacturers transfer the product into a oven where it’s exposed to heat. Temperatures can vary, though many powder coating curing ovens run at 250 to 350 degrees Fahrenheit. This heat allows the compounds within the powder to set, creating a stronger, longer-lasting hold.
Some of the most common polymer-based powders used in this manufacturing process include:
- Fusion-bonded epoxy
- Polyester epoxy
What Benefits Does Powder Coating Offer?
Powder coating offers several benefits for manufacturers. For starters, it doesn’t release volatile organic compounds (VOCs) that could otherwise lead to environmental pollution and health problems. Other coating processes, such as spray painting, release harmful VOCs. But the powder materials used in powder coating are completely free of VOCs.
Another benefit of powder coating is that it can protect metal surfaces from rust and corrosion. Steel, iron and other common metals are susceptible to rust and corrosion when exposed to moisture. Even small amounts of moisture, including airborne moisture in the form of humidity, can cause these metals to develop rust. However, powder coating will create a barrier of protection over the metal that prevents moisture from reaching it.
Many manufacturers prefer powder coating over spray painting because it has faster curing times. It can take up to 24 hours for spray paint to dry and even longer for it to cure. In comparison, powder coating typically cures in less than a half-hour.