Powder coating is used to protect materials from changing overtime due to atmospheric influence. Common items to be powder coated include household appliances, automobiles, bicycle frames, car rims, and architectural steel. To complete a powder coatings process through curing, an oven is required. Not just any oven, but a powder coating oven.
In this resource, we will answer frequently asked questions about powder coating ovens.
What is a powder coating oven and how does it work?
A powder coating oven is an industrial appliance used for thermal processing. Using heat to cure materials during the powder coatings process improves the strength and durability of certain materials. This is done by the heat accelerating a physical or chemical change within the material. The industrial powder coating ovens are commonly used for curing painted or powder coated finishes. It can also be used for polystyrene or composite parts, or for processing raw materials such as rubber, metals, adhesives, and thermoset polymers.
The powder coating oven is typically heated by a gas, oil, or electric powered heating system. The heating system may use direct flame-to-air heating of the oven environment or may use an indirectly-fired system where a heat exchanger isolates the oven interior from the combustion process. Some ovens may use a heat exchanger that is filled with steam rather than hot air. Industrial ovens that are intended for special purposes may use other heating methods, such as gas or electric infrared panels to direct heat energy onto the material in the oven.
How does the powder coatings process work?
Powder coating involves three steps – preparation, coating, and curing the part coating once applied.
Preparation for the part requires wiping it down with a cleaner or, for more complex cases, using blasting equipment to clean rusty parts with abrasive blast media. To coat the part, a powder coating gun and a powder spray booth are typically used. Once the part is coated, it is then cured at 400ºF. During this process, the applied powder is heated until it melts and forms a solid coating on the surface. Once completely cooled, the part is ready for use.
What materials can be used in a powder coating oven?
For powder coating ovens, the general rule of thumb is that any solid surface material that can safely endure high temperatures, such as 400ºF, can be treated. Some of these materials include:
- Most metal products (aluminum, stainless steel, mild steel, and steel alloys)
- Certain plastics, wood, and MDF products
- Treated steel products, including those with a galvanized or electroplated surface
The type of material you use is crucial since most powders require temperatures of 350ºF to 450ºF for proper curing. During the curing process, the material has to be heated for a set period of time at a set temperature at this height. The higher the temperature, the faster the part will reach a temperature where the powder melts and flows together. However, some finishes, such as high gloss white, can become discolored when exposed to excessive heat. Not only is accurate control of the temperature important, but it is also important to pay attention to what material you are using and making sure it is being heated at the appropriate temperature.
Reliant Finishing Systems is a leader in the powder coatings equipment industry. We build dependable, energy efficient powder coatings, painting, and industrial curing equipment. To learn more about the powder coatings process and equipment, visit our resource of frequently asked questions here. If you have any questions about powder coating ovens, fill out our form to talk to one of our powder coatings experts.