Manufacturer of Metallic Coating Line: Danieli Wean
The metallic coating line is where the steel substrate is coated with a protective, proven combination of metals that provide effective corrosion resistance. At Steelscape, the protective metallic coatings provided include TruZinc® (galvanized) and ZINCALUME® (Galvalume®). The metallic coating line consists of accumulation towers at both the entry and exit of the line allowing the steel to be accumulated for a short period time. This ability enables the line to launch a new coil or remove a finished coil while the rest of the line continues to run at a consistent speed. Precision can be maintained at every part of the process, resulting in a consistent surface and even coating.
- The coil comes from the cold rolling mill to the coating line via one of two payoff reels. The end of each coil is sheared. The new ends must be welded together to create a continuous band of steel.
- The tail of one coil and the head of the next are welded together using an electric seam welder.
- The steel enters the first accumulator tower.
- The steel is cleaned, rinsed and dried.
- The cold steel band enters the furnace. The purpose of the furnace is to do one final cleaning of the surface, and to heat the steel to develop the proper mechanical properties.
- The steel goes straight from the furnace into the coating pot. After it is coated, the steel passes through the pair of “air knives” where a high-pressure blast of air strips off the excess coating. The air knives work in conjunction with a computer-controlled gauge to create the customer’s specified coating thickness.
- The steel runs through a cooling tower, taking the strip almost back to room temperature.
- At the customer’s request, the steel can be run through a surface-conditioning mill to create a smooth surface for painting.
- The tension leveler pulls the steel taut while passing over a series of rollers to provide superior flatness.
- Any steel that is not destined for the paint line receives a chemical treatment that provides interim protection against coating deterioration.
- The steel enters the exit accumulator, waiting to be coiled again.
- The steel is re-coiled onto the tension reel and sent for painting or packaging.