Powder coating is a kind of coating applied as a dry, free-flowing powder using an electrostatic process. It is then curled using ultraviolet light or through heat using a curling oven. Manufacturers use the process for designing metal finishes. A powder coating is the new alternative to a paint coating because it is better, durable, high-quality, more appealing, and has a low environmental impact.
Powder coating can also be used for coating material other than metal, such as concrete, plastic, and steel. The process is suitable for both outdoor and indoor use. Besides, it is a cost-effective coating and finishing option.
Types of Powder Coating
Powder coating can be divided into two major categories; thermoset and thermoplastic powder coating.
Thermoplastic Powder Coating
Thermoplastic powder coating is a type of finish that becomes very soft and liquid when hot. Heating eliminates the chemical bonds, which makes this type of powder coating reversible. Therefore, material coated using this type of finish can be recycled and reused. This type of coating is usually thicker, which makes it more durable in comparison to thermoset coating. Therefore, it is preferred for heavy-duty coated equipment, auto parts, metal, and refrigerators.
Thermoset Powder Coating
Thermoset coating works quite differently from thermoplastic coating because the chemical bonds in this coating only form when the coating is cured (heated). Therefore, the coating can’t be recycled because it infuses the surface once cured. This type of powder coating is great for coating equipment used in high heat areas. The chemical bonds prevent the coating from melting away. Thermoset coating is cheaper than thermoplastic coating.
How is Powder Coating Done?
Before beginning the powder coating process, it is important to ensure that Powder Coating Equipment Manufacturers produce quality powder coating equipment. Having the right equipment ensures that you do professional coating work and that your coat is durable. Such equipment includes:
- Cleaning and degreasing equipment.
- A spray gun.
- A spraying booth.
- A curing oven.
- A piece of ultraviolet treatment equipment.
Powder coating begins with a target surface preparation process. Preparation determines how well the powder coat adheres to the target surface. The most common preparation practice done here is cleaning, which prepares the surface for the powder coat. Commonly, cleaning is done either by phosphate rinsing or degreasing; then, quick water rinses to finish the process. That prepares the surface for spraying. Other cleaning methods can be used depending on the material in question.
After cleaning, the next stage is powder coating, where a polymer resin, pigments, flow modifiers, curatives, leveling agents, and other additives are melted together. Preheating allows the coating to be uniform. The melted mixture is cooled to harden the coating, then ground into a fine powder.
The ground powder is then put in an electrostatic paint sprayer which is used for application. The gun positively charges the powder, which accelerates the powder’s components. It helps strengthen the chemical bonds, which fully solidify when cured. The good thing about powder coating is that more coating layers can be added after curling, a practice that helps improve durability.
Final Thoughts
Powder coating is the process of applying powder coating on surfaces using an electrostatic process. The surface is then curled using heat to help solidify the chemical bonds of the coating. Powder coating is used for coating metal, concrete, steel, and plastic materials.
