Powder coating – durable and customizable surface treatment method

Powder coating is a surface treatment method in which powdered paint is sprayed onto the surface of a product. The powder adheres to the grounded object, after which it is melted in an oven, forming a smooth, treated surface. When done correctly, powder coating is an environmentally friendly process that provides a durable, visually appealing finish without solvents or unpleasant odors.

At Ouneva Group, powder coating services are provided by Top Speed Oy in Jyväskylä and Ouneva Oy in Kovero. Top Speed Oy specializes exclusively in powder coating services, where even the most challenging metal products are treated with decades of experience. Ouneva Oy’s specialty is the surface treatment of sheet metal products.

Why choose powder coating for your product?

Powder coating is a cost-effective, durable, and high-quality coating method suitable for various materials. A powder-coated part resists mechanical and chemical wear exceptionally well. Benefits of powder coating include fast processing time and the ability to immediately proceed with post-treatment steps like assembly. Compared to wet painting, powder coating is a more environmentally friendly way to provide a visual and long-lasting surface.

Powder coating in brief

In powder coating, powdered paint is sprayed onto a grounded metal object using a powder spray gun. As the paint is sprayed, the powder becomes electrically charged (either negatively or positively, depending on the type of spray gun), which causes the grounded object to attract the particles. The object is coated either fully or partially (with masked areas), then moved to an oven via a coating line. In the oven, the dry powder melts and cures into a smooth, hardened surface.

Pretreatment and why it’s important

Pretreatment is the most crucial step before powder coating to ensure a high-quality surface. The product is chemically cleaned to remove grease or residues from previous manufacturing stages. Any residue can hinder paint adhesion or application since grounding does not work effectively on a dirty surface. Cleaning also ensures that no metal particles or machining debris remain under the paint. Ouneva Group’s coating processes always include degreasing and a corrosion-resistant pretreatment.

After washing, chemical pretreatment is carried out. Ouneva Group uses zirconium silane, a commonly used conversion treatment for steel, galvanized steel, and aluminium. It improves corrosion resistance and paint adhesion. These chemicals are phosphate-free and thus more environmentally friendly.

The entire powder coating process, including pretreatment, is carried out in-house at Ouneva Group on the same automated line. Even complex parts are handled automatically on our powder coating lines. Our skilled surface treatment professionals ensure every piece is prepared and coated with care and quality.

 

Material information in brief

Powder coatings consist of binders, hardeners, pigments, fillers, and additives. They are 100% dry and contain no solvents. Oversprayed powder is collected and recycled via a recovery system in the process, typically achieving over 80% material efficiency—sometimes up to 95% depending on the material.

There are many types of powder coating materials, each with specific properties. The right material is selected based on the product’s environment and use, desired surface appearance, and customer requirements. The most common materials include:

Epoxy and epoxy-polyester

  • Suitable for indoor use
  • High mechanical durability
  • Good chemical resistance

 

Polyester

  • Suitable for outdoor use
  • Excellent weather and UV resistance
  • Good for products expected to endure impact or abrasions

 

Polyurethane

  • Suitable for both indoor and outdoor use
  • Excellent mechanical and UV resistance
  • Provides a smooth and glossy finish

 

Powder coatings can also offer special features based on customer needs, including electrical conductivity or insulation, antibacterial properties, heat resistance, and extreme durability. Ask our experts for more information if your product requires special surface treatment.

About product design

If powder coating is planned from the start, a few design considerations help ensure the best result:

  • Color, coating thickness, and surface quality requirements
  • Hanging capability (hook or magnet)
    • Orientation and stability for jigs or racks
    • Optimal coating and washing orientation, especially for enclosure-type parts
  • Water drainage
  • Visual quality requirements
    • Desired finish: smooth, glossy, or effect surface
  • Corrosion resistance requirements
  • Other special coating requirements
  • Areas that require masking during painting, such as threaded sections
  • Environmental exposure classification

 

We’re happy to assist with any design-related questions. Please contact us via our contact form!

Summary

Powder coating is a surface treatment method where dry paint powder is sprayed onto a grounded part. The spray gun charges the particles, which then adhere evenly to the part’s surface. After spraying, the powder is melted into a smooth surface in an oven.

Powder coating is ideal for products requiring good protection and a visually appealing surface. Most powder coating processes are automated, but for complex parts, our professionals’ expertise ensures high-quality results.

In product design for powder coating, several factors should be considered. It’s essential to ensure the available coating system can achieve the required appearance and corrosion protection. This often includes considering mechanical pretreatment during the product design phase.