Automated powder coating line is an advanced surface treatment process that uses industrial powder coating equipment, such as electrostatic sprayers, to evenly apply powder coating to the surface of workpieces. Under the action of static electricity, the powder adheres firmly to the workpiece, forming a powder coating layer.

The coating is then smoothed and formed into the final surface through high-temperature baking and curing inside the powder coating booth. Typically, the coating thickness is maintained between 40-120μm, providing excellent mechanical strength, adhesion, corrosion resistance, and aging resistance. Compared to traditional spray painting processes, it offers superior performance and lower costs.

Automated powder coating line is a surface treatment process based on the principle of electrostatic adsorption. The core of the process is to use a high-voltage electrostatic field to charge the powder particles, and through aerodynamic forces, achieve uniform coating on the surface of the workpiece. This process system consists of a powder supply device, high-voltage electrostatic generator, spray gun, and powder recovery device, forming a closed-loop system.

The powder supply device by Hinah uses compressed air to fluidize the powder, and the powder is precisely delivered through a Venturi powder pump to achieve accurate powder-air two-phase flow. The dynamic adjustment function of the system meets the process requirements of 40-120μm coating thickness. The electrostatic generator can output up to 100kV of direct current voltage, using corona discharge to ensure that the powder particles achieve a charge-to-mass ratio of 0.8-2.0mC/kg, effectively overcoming the Faraday cage effect and ensuring that the coverage rate for workpieces with complex geometries reaches over 98%.

Composition of Automated Powder Coating Line

Powder Supply Device

The powder supply device fluidizes the powder using compressed air, forming a powder-air mixture, which is then transported to the spray gun via a Venturi powder pump and powder transport pipe. The powder supply device has a regulation function to adjust the amount of powder and air pressure to meet the coating thickness requirements for different workpieces.

Electrostatic Generator

During the powder coating process, the electrostatic generator generates high voltage and low current, causing the spray gun's electrode needle to discharge in the air. When the powder exits the spray gun, the powder particles acquire an electrostatic charge and uniformly adhere to the grounded surface of the workpiece through electrostatic adsorption. Automated powder coating line equipment can typically generate up to 100kV of voltage, ensuring high coverage, even overcoming the Faraday effect on internal angles or deep cavities, achieving uniform spraying results.

Spray Gun

The structure of the spray gun is carefully designed to ensure the stability of the powder's charge. The spray gun in automated powder coating line equipment is typically equipped with multiple functions to meet the needs of different types of workpieces and spraying scenarios.

Powder Recovery Device

The powder coating booth is usually equipped with a high-efficiency powder recovery system that collects the powder not adhering to the workpiece and reuses it. This not only reduces powder waste but also significantly lowers production costs.

Advantages Compared to Traditional Solvent-Based Coating

• Material Efficiency: The combination of cyclone separation and filter cartridge recovery systems achieves a powder utilization rate of 95-99%, reducing coating material loss by 25-40% compared to traditional spraying.

  
  

• Environmental Performance: The process completely eliminates VOC emissions and complies with the ISO 14001 environmental management system standards. Each 10,000 square meters of coating can reduce the use of organic solvents by 12 tons.

  
  

• Process Efficiency: The single-layer coating thickness is 50-150μm, with curing conditions at 180℃±5℃ for 20 minutes. Compared to wet spraying, this process saves more than 30% of energy and improves production line efficiency by 35-40%.

  
  

• Coating Characteristics: The cross-linked epoxy-polyester hybrid coating system has a pencil hardness of ≥H, salt spray resistance exceeding 1,000 hours, and adhesion reaching ASTM D3359 1B level.

In terms of equipment configuration, the intelligent spray gun is equipped with a multi-axis linkage mechanism and CCD vision positioning system, achieving a spraying trajectory precision of ±0.5mm. The powder recovery device adopts a three-stage treatment design (cyclone separation + cartridge filtration + nanomembrane interception), ensuring that the dust content in the exhaust air is below 5mg/m³. This technology has now expanded into high-end manufacturing fields such as automotive chassis components, photovoltaic brackets, and medical devices. Specifically, in aluminum alloy wheel coating, it can achieve film thickness control of 80μm±5μm with hardness exceeding 4H.

Comparison Between Automated Powder Coating Line and Traditional Painting Processes

• Efficiency: As powder coating is a one-time film formation process, production efficiency can be increased by 30%-40% compared to painting processes.

  
  

• Energy and Environmental Benefits: The powder coating process does not require solvents, eliminating the production of harmful volatile organic compounds (VOCs), significantly reducing environmental pollution and lowering energy consumption by approximately 30%.

  
  

• High Material Utilization: Automated powder coating line equipment is typically equipped with a powder recovery device, achieving a powder utilization rate of over 98%. The unused powder can be recovered and reused.

  
  

• Superior Coating Performance: Powder coatings can achieve a thickness of 50-120μm, with excellent adhesion and corrosion resistance, resulting in an aesthetically pleasing and durable final product.

  
  

• Low Rework Rate: If defects are found before curing, re-spraying can be performed directly, further reducing the scrap rate.

Application and Future Outlook of Automated Powder Coating Line

The automated powder coating line process is widely used in industries such as automotive manufacturing, home appliance production, construction materials, and electronic equipment. With increasingly stringent environmental regulations and growing demands for cost control and product quality, the powder coating process is expected to be applied in more industries.

In the future, with further upgrades to powder coating booths and coating equipment, the degree of automation and intelligence will continue to improve, providing enterprises with more efficient, energy-saving, and environmentally friendly surface treatment solutions.

From an industry development perspective, with the application of robot seventh-axis linkage systems and powder fluidization numerical simulation technology, the next generation of equipment is moving toward intelligent closed-loop control. According to Frost & Sullivan, the global powder coating market is expected to exceed 18 billion USD by 2025, with an annual compound growth rate of 8.7% in the Asian market. Future technological breakthroughs will focus on low-temperature curing (below 120°C) powders and the industrial application of nanocomposite coatings, which is expected to further expand the application boundaries in heat-sensitive base material fields.