15.2 steel strand Manufacturers consider steel strands to be steel materials composed of multiple steel wires twisted together. The carbon steel surface can be coated with zinc, zinc-aluminum alloy, aluminum, copper, and epoxy coatings as needed. Commonly used steel strands include galvanized steel strands and prestressed steel strands. The commonly used prestressed steel strands range in diameter from 9.53 mm to 17.8 mm, with a few having larger diameters. Each prestressed steel strand generally consists of 7 wires, but can also have 2, 3, or 19 wires. The wires can have metallic or non-metallic corrosion-resistant coatings. Unbonded prestressed steel strands are coated with anticorrosion grease or wax and then wrapped with HDPE, resulting in unbonded prestressed steel strands.

　　15.2 steel strand manufacturers believe that the manufacturing process of steel strands is divided into single-wire manufacturing and steel strand manufacturing. Single wires are manufactured using (cold) drawing technology. Depending on the material, they can be high-carbon steel wire rod, stainless steel wire rod, or medium-low carbon steel wire rod. If galvanizing is required, the single wires should be electroplated or hot-dipped. A stranding machine is used to twist multiple wires into the final product during steel strand manufacturing. After forming, prestressed steel strands require continuous stabilization; products are generally collected on a girder wheel or completed by an axelless coil.

　　15.2 steel strand manufacturers believe that galvanized steel strands are commonly used in load-bearing ropes, tie wires, reinforcing cores, etc. They can also be used as ground wires for overhead power transmission, barrier cables on roadsides, or structural cables in building structures. Commonly used prestressed steel strands include uncoated low-relaxation prestressed steel strands and galvanized steel strands. They are frequently used in highway bridges, railway bridges, urban overpasses, urban light rail, high-rise buildings, hydropower dams, ports and wharves, rock slope anchorages, foundation reinforcement, tunnel mine top anchorages, prestressed space trusses, subways, large buildings and halls, warehouses and workshops, tower buildings, heavy lifting, sliding intermittent pushing, bridge and tunnel pushing, large containers and ships, sleepers, bridge bearing replacement, and bridge and building reinforcement.

　　15.2 steel strand manufacturers believe that steel strands (also called steel cables) are mainly used as load-bearing structural materials in bridge construction. Steel strand products have very high requirements for corrosion resistance and salt spray resistance (especially for coastal or cross-sea bridges), requiring a 3000-hour salt spray test. To prevent road icing in winter, high-grade highways often use salt for de-icing, so the reinforcement in cement products is required to have excellent resistance to saltwater corrosion. The reinforcement used in high-rise buildings also requires excellent corrosion resistance to extend its service life. Epoxy-coated steel strands (reinforcement) can increase the service life of buildings by 3 to 6 times. This new type of steel strand (steel bar) with excellent corrosion resistance has attracted widespread attention both domestically and internationally, representing a new application area for powder coating technology.

　　 15.2 steel strand Manufacturers estimate that China's annual steel strand production is currently about 1.6 to 2 million tons. Of this, epoxy-coated steel strands (steel bars) account for 20%, with a production of 320,000 to 400,000 tons. Each ton of epoxy-coated steel strand (steel bar) requires approximately 50 to 70 kg of epoxy powder coating, meaning that China currently needs 16,000 to 20,000 tons of epoxy powder coating annually in this area. China's steel strand (reinforcement) production has a year-on-year growth rate exceeding 20%. The application ratio of epoxy-coated steel strands (reinforcement) is also increasing rapidly year by year. Therefore, epoxy-coated steel strands (steel bars) represent a very attractive market for the powder coating industry.