Powder coating has been a popular dry-finishing process in North America since the 1960s. The powder coating process is relatively versatile and offers a smooth, protective, and decorative finish. It can be used on a wide range of surfaces, including metals, medium-density fibreboard, and even plastic. Powder-coated surfaces become resistant to corrosion, scratch, and even chemicals.
In today’s industrial coating industry, efficiency and quality are of equal value to customers. And powder coating can help you towards this end. Minnesota Industrial Coatings provides high-quality powder coating to help ensure that you produce the best products. We also offer e-coat services. Contact us today to learn more about our services.
The Powder Coating Process
There are two types of powder coating: Thermoplastic and Thermosetting. While each type is used for different surfaces, the coating process is the same. Several steps must take place to powder coat properly:
The substrate is first cleaned to remove all dirt, grease, grime, and any other residues. Suppose the substrate has materials stuck on the surface, such as existing paint or rust; the process is conducted using a blast room. The blast room uses sand-like grit or pressurized liquid to blast surfaces clean of any residues.
At times, dry-off ovens are used. These ovens serve two purposes: (1) they ensure that the substrate is completely dry after it has been washed, and (2) they help ensure that the material is up to the suitable temperature for the powder coating process.
Removing binding materials, especially sealed or threaded ones, is also crucial. Any bolts, nuts, or lubricated parts should be extracted before beginning the process. Also, you should mask any part of the surface that won’t be coated.
Once the preparation process is complete, the material is ready to be coated. Just like with painting, powder coating requires the use of a gun to spray the coat onto the substrate. However, unlike painting, powder coating uses electromagnetic charges. Once the powder is in the gun, it is charged via friction or electricity.
On the other hand, the substrate is grounded to give it the opposite charge of the powder in the gun. Since opposites attract, spraying the powder out of the gun will lead to it being automatically attracted to the substrate, completely coating it. You can apply multiple layers of coating provided that the substrate is grounded.
Since most non-metallic materials aren’t groundable, their application process is different. They are preheated and then dipped into the liquified powder rather than being coated using electrically charged particles in a gun.
After powder application, thermoset materials should be subjected to the curing process to convert the powder into a film. When the powder is heated, it melts and flows together, creating durability and strength associated with powder coating. The powder doesn’t melt again after this first time. As such, powder-coated substrates can be used for numerous different purposes, even when heat isn’t involved.
Generally, the heating process entails heating the substrate in temperatures ranging between 325-450°F for 10 minutes to more than an hour. That said, the substrate’s shape and size may impact the temperature and time required for curing. The heating process can be conducted using an infrared oven, a conventional oven, or a combination oven that combines these types.
Organizing the powder coating process properly is essential for its successful completion.
Material Consideration for Powder Coating
Powder coating is an excellent way to protect a substrate and considerably increase its durability. Even so, it’s essential to remember that for powder coating to work, the substrates should be able to withstand the high temperatures they will be subjected to during the powder coating process.
Having said that, there are two types of powder-coating materials: thermosets and thermoplastics.
- Thermosets: These go through a permanent cross-linking process when cured. Thermosets become harder and more brittle than thermoplastics when cured. Examples of thermosets used in the powder coating process include Epoxy, Acrylic powder, and Epoxy-polyester hybrid.
- Thermoplastics: These materials can melt in high temperatures. As such, they are suitable for recycling and reforming but not for situations that require exposure to intense heat. Thermoplastics such as polyvinyl chloride, nylon, polyester powder, and polyolefin are ideal for powder coating due to their chemical-resistant and wear-resistant qualities.
Powder Coating Finishes and Capabilities
Powder coating is applicable in a wide range of colors, textures, finishes, and thicknesses that aren’t readily attainable when you use conventional liquid coating techniques. Capable of being manufactured in basically any color, powder coating materials can be formulated for both decorative and protective applications. The resultant powder coating finish attained by the powder material ranges from glossy to matte and clear to glitter or metallic.
The powder coating process can also produce various thicknesses. This process can produce thicker, even coats when you use the fluidized coating technique. On the other hand, you can get thin, even costs, when you use the ESD technique. Various textures are also available for hiding surface imperfections and decorative purposes.
Powder Coating Applications
The application of powder coating has been growing over the years as more industries coat more products. In fact, the size of the powder coating market is expected to surpass 16.8 billion by 2026. Some of the industries that use powder coating include:
- Appliances: It’s used in front and side panels in various air conditioner cabinets, refrigerators, washer lids, microwave oven cavities, dishwasher racks, and water heaters.
- Automotive: the automotive industry uses powder coatings for bumpers, door handles, radiators, filters, sections with decorative accents and trims, hubcaps, wheels, and different parts of the engine.
- Architecture/construction: In the architecture industry, powder coating coats aluminum extrusions for window and door frames. On the other hand, the construction industry uses it on posts, light poles, guardrails, fencing, and signs.
- Day-to-Day Products: Powder-coated products have numerous daily uses. These include light fixtures, antennas, and a wide range of electrical components.
Powder coating offers several benefits, including durability, optimum material utilization, and a shorter curing process.
Get Full-Coverage Coating and More Today
At Minnesota Industrial Coatings, we consistently offer high-quality powder coating and electrocoating. We’re a production volume capacity facility that leverages the Parker Ionics powder delivery system.
Also, as part of the Elemet Group, Minnesota Industrial Coatings has access to sister companies offering robotic welding, metal spinning, punching, waterjet cutting, assembly, and automated machining. Our customers, therefore, have a one-stop shop for all their metal needs.
Contact us today to request a free estimate of our services.