Production of Flame-Retardant and Fire-Resistant Cable Trays

Fire-resistant cable trays are manufactured using high-quality steel or FRP/GRP materials with specialized fireproof coatings to ensure flame retardancy, structural integrity, and long-term durability.

Materials Used

Fire-resistant cable trays are typically made from cold-rolled steel sheets or glass fiber-reinforced plastics (FRP/GRP). Steel provides high load-bearing capacity and durability, while FRP/GRP offers corrosion resistance, lightweight properties, and electrical insulation advantages . The steel skeleton is carefully processed to ensure smooth, flat surfaces without burrs or sharp edges, and the cross-sectional shape is uniform, free from bending, twisting, or cracks . FRP/GRP trays are made from glass-armored thermoset fire-resistant resins, which combine strength with fire retardancy .

Manufacturing Process

1. Steel Skeleton Formation: High-quality cold-rolled steel sheets are cut, shaped, and mechanically processed into the tray skeleton. The process ensures high load-bearing capacity and a defect-free structure .
2. Fireproof Board Production: For enhanced fire resistance, fireproof panels are made from siliceous and calcrete materials mixed with fibers, lightweight aggregates, adhesives, and chemical additives. These panels are often produced using autoclave technology to ensure uniformity and strength .
3. Application of Fireproof Coating: A fire-retardant coating is applied to the tray surface. This coating typically contains polymer synthetic resins, flame retardants, blowing agents, carbonizing agents, and high-temperature refractory materials. When exposed to high temperatures, the coating expands and forms a spongy carbonized layer, insulating the steel structure and preventing deformation or collapse .
4. Assembly and Fittings: Cable trays are assembled with various fittings such as bends, tees, reducers, and covers. FRP/GRP trays may include ladder-type or perforated designs, along with accessories like coupler plates, hold-down clips, and divider strips . All fastenings must use fire-rated accessories to maintain the system's fire resistance .

Functional Benefits

• Fire Resistance: Prevents the spread of flames and maintains electrical continuity during fire events, with some systems tested to E90 or E60 standards, meaning circuits remain functional for 90 or 60 minutes under fire conditions .
• Corrosion and Chemical Resistance: FRP/GRP trays resist rust, chemical attack, and environmental degradation .
• Non-Toxic and Pollution-Free: Fireproof coatings are designed to be non-toxic and environmentally safe .
• Ease of Installation and Maintenance: Modular designs and smooth surfaces allow for quick installation and easy cable management .

Standards and Testing

Fire-resistant cable trays are tested according to EN 1363-1 and other international standards to ensure structural integrity, load-bearing capacity, and fire performance. Manufacturers conduct real-world fire tests rather than relying solely on simulations, ensuring reliability in critical installations such as fire control rooms, elevators, smoke fans, and automatic fire alarm systems . In summary, the production of flame-retardant and fire-resistant cable trays involves high-quality materials, precise mechanical processing, advanced fireproof coatings, and rigorous testing, resulting in durable, safe, and compliant cable management systems suitable for industrial and commercial applications.