Definition
Powder coating is a dry finishing process that uses fine, dry pigmented polymer powder instead of liquid paint. The powder is electrostatically charged and sprayed onto workpiece surfaces, then cured in a high-temperature oven to form a tough, uniform protective decorative film.
It is widely applied to metals, and also compatible with heat-resistant composites and high-temperature engineering plastics.
Working Principle
- Pre-treatment: Sandblasting / degreasing to clean and roughen parts for better adhesion;
- Electrostatic Spraying: Powder particles gain negative charge via spray gun, attracted to grounded metal workpiece;
- High-temperature Curing: Parts go into oven at 180–200°C, powder melts, flows and cross-links into a solid continuous coating layer.
Main Types of Powder Coatings
- Polyester Powder Most common outdoor grade. Excellent UV resistance, anti-fading performance. Ideal for outdoor hardware, automotive parts, outdoor equipment, aluminum profiles.
- Epoxy Powder Strong corrosion & chemical resistance, low cost, poor anti-UV (will chalk outdoors). Used for indoor products: cabinets, machinery frames, pipe fittings.
- Polyurethane Powder Super smooth, high gloss, flexible film, outstanding wear resistance. Premium choice for high-end decorative metal parts.
- Hybrid Epoxy-Polyester Powder Balanced cost and surface finish, only suitable for indoor use.
Key Advantages
- Superior Durability Thicker coating layer (30–120 μm) than liquid paint, great anti-rust, scratch, impact and chemical resistance. Long service life with minimal maintenance.
- Eco-Friendly & Cost-Effective No solvent, zero VOC emission, meets global environmental standards. Over-sprayed powder can be recycled and reused (up to 95% material utilization rate).
- Uniform Consistent Finish Even coverage on complex geometry, edges, recesses and hollow structures; wide range of textures: glossy, matte, textured, hammer tone, metallic.
- Rich Color Options Customizable solid colors, metallic, transparent, matte, wrinkled, sand grain textures as customer requests.
Suitable Substrates
- Metals: Aluminum alloy, steel, stainless steel, zinc die castings, iron
- Heat-resistant composites & high temp resistant engineering plastics
Standard Production Flow
CNC Machining / Die Casting → Sandblasting / Degreasing → Electrostatic Powder Spraying → High Temp Curing → Finished Parts
Process Overview
Powder coating provides robust, long-lasting dry film protection for metal components. Featuring zero volatile solvents, recyclable powder materials and versatile color & texture options, it delivers superior anti-corrosion and scratch resistance for both indoor and outdoor applications.
Common Matching Surface Treatment Combinations
- Sandblasting + Powder Coating (matte uniform base coating)
- Polishing + Clear Powder Coating (bright mirror metal protection)
- Anodizing + Top Powder Coating (dual-layer corrosion resistance)