Customized Powder Coating Production Line for Cold Rolled Steel Plates

This powder coating production line is designed for cold rolled steel plates of various dimensions. The spray booth is manufactured from PVC, providing excellent corrosion resistance and durability. The coating process combines automatic electrostatic spraying with supplementary manual coating, ensuring uniform coverage even on edges and complex areas.

An overhead conveyor system is adopted to guarantee stable, continuous movement of the workpieces throughout the coating process, while loading and unloading operations are performed manually to maintain flexibility.

Production Line Flow

Manual loading → Automatic spraying + manual spraying → Powder curing → Natural cooling → Manual unloading

Powder Coating Process Description

1. Surface Preparation

Surface preparation is the first and most critical step in the powder coating process for cold rolled steel plates. This stage removes oil, grease, rust, and other surface contaminants through cleaning and degreasing, ensuring a clean substrate and optimal coating adhesion.

2. Pre-Treatment

After surface preparation, the steel plates undergo a pre-treatment process to improve coating adhesion and corrosion resistance. Typical pre-treatment methods include chemical cleaning, phosphating, or other suitable conversion treatments, depending on application requirements.

3. Drying

Following pre-treatment, the workpieces pass through a drying stage to eliminate residual moisture from the surface. Proper drying is essential to prevent coating defects and to ensure strong bonding between the powder coating and the steel substrate.

4. Powder Coating Application

Once dried, the cold rolled steel plates enter the spray booth for powder coating application. The powder is electrostatically charged and applied using automatic spray guns, with additional manual spraying performed as needed. The charged powder particles are attracted to the grounded steel surfaces, resulting in even and consistent coverage.

5. Powder Curing

After coating, the workpieces are transferred to a curing oven. Under controlled temperature conditions, the powder melts, flows, and chemically cross-links to form a continuous, smooth, and durable coating film with excellent mechanical and protective properties.

6. Cooling

After curing, the coated steel plates undergo natural cooling. This step stabilizes the coating structure and ensures the finished surface maintains its performance characteristics and appearance.

7. Quality Inspection

The final stage is quality inspection. Each coated workpiece is examined for coating thickness, surface appearance, adhesion, and overall finish quality to ensure compliance with specified technical and quality standards.