Foil

Foil, like sheet and plate, is produced by passing aluminum between rolls under pressure. Foil is the thinnest of these three products and is 0.0079 inch or less in thickness. Foil is produced from sheet coils that are heated and then passed through high-speed foil rolling mills.  (For a more thorough explanation of the sheet, plate, and foil production process, please visit the Sheet and Plate page in the Industry section of this website by clicking here.

Foil is considered to be the beauty of the flat-rolled family because of its shiny one-sided finish. Foil is shiny on only one side because as it passes through the final foil mill, two thicknesses of foil are rolled together. The sides facing each other emerge with the dull finish, while the sides in contact with the foil mills come out shinier—due to the burnishing effect of the rollers.

Flexible packaging and foil containers account for about three-fourths of all foil used, but the remainder goes into some exciting applications.

For instance, foil-backed building insulation reflects heat and provides a protective vapor barrier. Foil in electrical capacitors provides compact electrical storage and, if the foil surface is treated, its oxide coating works as an insulator. Aluminum foil capacitors are found in virtually all electrical equipment, from television sets to computers.

Formed into fins, foil is the heat exchanger in some air-conditioning units and baseboard space heaters. Formed into honeycomb and sandwiched between sheets of aluminum, foil helps provide structural strength in aircraft and satellites.