Metalfoil

Metalfoil, or metal foil, is a thin sheet of metal produced by rolling metal into very small thicknesses. Foils are typically measured in tenths to hundredths of a millimeter, with common thicknesses from about 0.006 mm to 0.2 mm. The most widely used foil material is aluminum, but foils are also produced from copper, tin, nickel, titanium, gold, and silver.

Foils are highly ductile and flexible, making them suitable for wrappers, laminates, and shielding. They can provide electrical conductivity and high reflectivity, and their barrier properties against gases and moisture depend on the metal and thickness.

Manufacturing typically involves rolling slabs through successive passes and, if needed, annealing to restore ductility. Foils may be finished or coated and laminated with plastics or paper to form composite materials for packaging and other uses.

Applications include food and pharmaceutical packaging, blister packs, electrical components such as foil capacitors and circuit shielding, heat exchangers and insulation, and decorative or architectural uses. Aluminum foil is widely recycled; laminates combining metal with plastics are more challenging to recycle. See also aluminum foil, metallized film, foil capacitor, thin-film metal.