Curing is the last step in the powder coating process before parts are packaged and shipped. During the curing process, the powdered coating becomes hard and uniform, creating a smooth, durable surface that will resist wear in many commercial applications.
When Does Curing Occur?
Powder-coated parts get cured at the end of the coating process. First, components must be prepared for coating. In most cases, components are blasted to create a smooth surface for adhesion and undergo pretreatment with various cleaners and solutions. Then if necessary, primer is applied, and any parts that don’t need a powder coating undergo masking to block them from receiving a powder coat.
After thorough preparation, the part gets sprayed with a powder coating. Only after these steps can the equipment be cured.
Why Is Curing Necessary?
Curing turns a polymer powder into a finished coating. Without curing, the powder coating can wipe off easily. Liquid paints set as they dry, but powdered finishes are already dry and must be set through heat.
This process uses heat to melt resins in the coating powder, so the powder creates a smooth film. With thermoplastic curing, the powders melt and flow into a uniform layer but can be remolded. Thermoset coatings gain a new chemical structure when cured, meaning they cannot melt again.
What Are the Steps of the Powder Coating Dry Process?
Curing must pass through four stages to ensure the best results:
- Melt point: Particles shift from solid to semi-liquid.
- Flow stage: The film is entirely liquid and begins to smooth.
- Cross-linking stage: Heat triggers a reaction that changes the chemical structure of the powder.
- Satisfactory cross-linking: Once the powder has developed enough, it can be removed from the heat to solidify.
What Temperature Is Needed to Cure Powder Coatings?
Powdered coatings are typically melted in an industrial oven at temperatures ranging from 325 to 400 degrees Fahrenheit. These industrial ovens often use natural gas to create heat. They also have a fan that distributes the heat evenly for a uniform coating.
How Long Does Curing Take?
Curing usually takes less than 25 minutes. The exact time and temperature used to cure a coated surface depend on several factors, including the size of the part, the thickness of the coating and the coating material used. Professionals can adjust heat and duration accordingly to create a smooth, durable finish every time.
Get Professional Powder Coating From Keystone Koating
Keystone Koating provides large-volume coating for commercial- and industrial-grade uses. Our team’s professional expertise helps us determine ideal curing temperatures and durations for a long-lasting finish. Contact us for a quote today.