Powder coating is a type of coating that is applied electostatically as dry powder. After that it is cured under heat to allow it to flow and form a skin. It is used for coating on metal and plastic parts.
Powders with low curing temperature and time are used for coating plastic parts.
Advantages of Powder Coating compared to traditional Liquid coatings:
- No volatile organic compounds (VOCs)
- Thicker coating thickness is achievable with Powder coating
- Powder coating typically provides a uniform visual appearance regardless of part orientation.
- Good scratch resistance, toughness and hardness
Types of Powder Coating
Based on chemical composition and cross linking structure power coatings are classified in two categories :
Thermoplastics are synthetic materials that can be formed multiple times. High temperature can melt thermoplastics. That’s why they are not good choice where part might be exposed to high heat. Thermoplastic powders has good wear and chemical resistance.
Following are the some of commonly used thermoplastic coats:
Nylon powders are generally used as a protective coating. They are durable and impact resistant. They offer good protection against a wide range of chemicals, solvents and oils.
FDA approved food contact grades are available. Due to low friction coefficient, nylon coating is used on gears and conveyor equipment.
Polyvinyl Chloride (PVC)
Polyolefin powder coat are resistant to abrasives and chemical. They offer a smooth surface and excellent adhesion properties.
Polyolefin coatings are used on components that require regular cleaning.
Thermoset powder coating makes a chemical cross-linking reaction that is non-reversible. This cross-linking changes the physical properties of the plastic, typically hardening them into a solid coating.
Following are the some of commonly used thermoset coats:
Epoxy Coatings are very durable, offer excellent hardness and very good chemical and corrosion resistance. These coatings provides smooth and uniform appearance.
But epoxy coating do not provide good weather resistance. When comes in contact with sun they fade and chalk. This makes epoxies better suited to indoor applications.
Epoxy Polyester Hybrid
Epoxies and polyesters are mixed to foam hybrid coatings. They offer very good mechanical properties, corrosion and chemical resistance.
Hybrid coatings chalks less and offer better weathering in outdoor conditions due to presence of polyester. But they are generally used for indoor products only.
To sum up, for powder coatings so many product options are available depending on your application. And thousands of colors and special effects options are also available.
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