Zincized Cable Tray Galvanizing Process

Cable trays are typically zinc-coated through hot-dip or electro-galvanizing processes to provide corrosion resistance, with hot-dip galvanizing offering superior durability for harsh environments.

Types of Galvanizing

Electro-galvanizing: This process deposits a thin, uniform layer of zinc onto the steel surface via electrolysis. The coating is bright and smooth but provides relatively limited corrosion resistance. It is generally suitable for indoor or less demanding environments and follows standards such as GB/T 26941.1-2011 . Hot-dip galvanizing: Steel components are submerged in molten zinc, forming a thick zinc-iron alloy layer topped with pure zinc. This method ensures excellent adhesion, superior corrosion resistance, and full coverage of edges, holes, and welds. It is ideal for outdoor, industrial, and coastal applications and adheres to GB/T 13912-2020 standards .

Manufacturing Steps

1. Pre-treatment: Steel is cleaned through pickling, rinsing, fluxing, and drying to remove oxides and contaminants .
2. Zinc Coating: For hot-dip galvanizing, the tray is immersed in molten zinc. The immersion time and withdrawal speed determine the coating thickness .
3. Post-treatment: Excess zinc is removed, and a thin passivating layer may be applied to prevent white rust during storage .
4. Fabrication Considerations: Pre-galvanized steel sheets (mill-galvanized) can be roll-formed into trays, but areas affected by cutting or welding rely on sacrificial zinc protection .

Coating Thickness and Standards

• Hot-dip galvanized trays: Minimum coating mass is typically 325 g/m² (~45 µm) for standard applications, but for marine or export conditions, a coating mass of 275 g/m² (~39 µm) is recommended to ensure uniform, dense protection .
• Electro-galvanized trays: Coating is thinner and less resistant, suitable for indoor use .
• International standards: Coating thickness and mass are specified based on steel thickness, with local thickness requirements ensuring long-term corrosion protection .

Advantages of Galvanized Cable Trays

• Reduces corrosion and extends service life .
• Provides smooth edges to prevent wire damage.
• Eliminates the need for additional hardware or grounding splices.
• Supports complex architectural designs and reduces installation time .
• Hot-dip galvanizing ensures full coverage, including welds and cut edges, offering sacrificial protection where the coating is breached .

Best Practices

• Use hot-dip galvanized steel sheets with sufficient coating mass for harsh or marine environments.
• Ensure proper pre-treatment and immersion times to achieve uniform coating.
• For long-term outdoor exposure, post-fabrication hot-dip galvanizing is preferred over pre-galvanized steel . By following these processes and standards, zincized cable trays achieve optimal corrosion resistance, durability, and reliability in both industrial and outdoor applications.