This powder coating production line is designed for spraying carbon steel sheets of various dimensions and shapes used in safes.
The spray booth is constructed with PVC panels, and the coating application combines both automatic spray guns and supplementary manual touch-up spraying. The pretreatment section runs on a skid-type ground conveyor, while the powder coating section operates on an overhead conveyor system that maintains a constant conveying speed.
Production Line Workflow
1. Welding Area Loading
A robotic manipulator places the cabinet body and door panel onto two independent work positions.
2. Metal Grinding
-
A robotic grinding unit polishes the weld seams on the cabinet body.
-
Door panel weld seams are manually polished, followed by full-surface manual sanding to ensure a smooth finish.
3. Phosphating Solution Treatment
Operators manually wipe the surfaces with a phosphating agent to improve coating adhesion and corrosion resistance.
4. Moisture Drying
The treated workpieces are dried at 40–50°C to remove any remaining moisture.
5. Manual Putty Application
Technicians apply putty to fill surface imperfections and ensure surface flatness.
6. Putty Drying
The putty layer is dried at 40–50°C to achieve proper hardness.
7. Manual Putty Sanding
After curing, the putty is manually sanded to obtain a uniform, smooth finish.
8. Workpiece Accumulation
Finished parts are accumulated—approximately 100 sets—before entering the next stage.
9. Mechanical Loading Transfer
The accumulated workpieces are automatically transferred to the next process via mechanical loading equipment.
10. Dust Removal
Operators use electrostatic dust blow guns to remove dust and fine particles from the surface.
11. Powder Coating Application
A combination of automatic spraying and manual reinforcement is used to ensure full and even coverage.
12. Powder Curing
The coated parts are cured at 200°C for 18 minutes, allowing the powder coating to fully crosslink and solidify.
13. Air Cooling
After curing, parts undergo forced air cooling to stabilize the coating.
14. Manual Installation of Casters
Casters are manually attached to the finished cabinet bodies.
15. Assisted Downloading to AGVs
Using human–machine collaborative handling, the completed units are placed onto AGV carts for transfer to the next workstation.
