How is it made?
Like galvanized, GALVALUME sheet steels is made by a “continuous hot dip” metal coating process. Cold rolled steel coils are welded end-to-end and processed continuously on the coating line at speeds up to 600 feet per minute. The uncoiled steel is first cleaned to remove rolling oils and mill dirt, and to reduce surface oxides so that the surface will accept the coating. The steel strip is first fed into a molten coating bath contained in an open top, brick-lined heated pot. The strip then passes around a roller submerged in the coating bath and exits the bath vertically, pulling out with it an envelope of the coating material. As it exits, the sheet proceeds through a pair of opposing air knives, which are positioned above the bath and equidistant from the surface of the sheet. Most modern production lines have a coating thickness gauge feed-back control, which automatically adjusts knife air pressure and position to ensure that a uniform coating is applied. Various finishing steps are carried out to complete the process, after which the strip is wrapped around a reel into a coated steel coil.