Refining
The first step in the process of making aluminum cans is the mining and refining of aluminum. Aluminum is found naturally in a mineral known as bauxite. When bauxite is refined to remove impurities, alumina or aluminum oxide is made, and it takes the form of a simple white powder. Running a continuous electric current through this powder removes the oxygen and melts the aluminum. Other materials are added in small amounts to help the aluminum resist corrosion and to add strength to it. Then the molten metal is cast into ingots, which are rolled into sheets of aluminum.
Shaping
Aluminum cans are formed from these aluminum sheets, which are unrolled, lubricated, and fed into a machine on a conveyor belt. A cupping press cuts out circles from the aluminum sheet and forms them into shallow cups. The cups are then drawn through a series of iron rings, which lengthens them, making them look like cans without tops. The tops of the cans are then cut to ensure that they're all the same height. Once these steps have been taken, the basic part of the can is formed, and it is washed and cleaned before moving onto the next part of the process.
Finishing
The can next goes to a label press, where it is painted and given a clear coat to protect the paint. The can is then placed inside an oven where the paint and coating are baked on to prevent damage. Once it's cooled, the inside of the can is sprayed with a coating to stop the materials of the can from leaching into the contents. The can is then baked again to seal this second coating. The bottom of the can is re-formed into a dome to add strength, and the uppermost part is narrowed so that the top may be placed on it at a latter time. Then all the cans are tested for leaks, put on pallets, and shipped to soft drink companies. The lids are cut, molded, and shipped separately and are applied after the soft drink is inside the can, sealing the beverage inside.
