What Is Aluminum Foil Made Up of?


Aluminum foil is made from an aluminum alloy which contains between 92 and 99 percent aluminum. Usually between 0.00017 and 0.0059 inches thick, foil is produced in many widths and strengths for literally hundreds of applications.

It also extends shelf life, uses less storage space, and generates less waste than many other packaging materials. The preference for aluminum in flexible packaging has consequently become a global phenomenon. In Japan, aluminum foil is used as the barrier component in flexible cans. In Europe, aluminum flexible packaging dominates the market for pharmaceutical blister packages and candy wrappers. The aseptic drink box, which uses a thin layer of aluminum foil as a barrier against oxygen, light, and odor, is also quite popular around the world.

Aluminum is the most recently discovered of the metals that modern industry utilizes in large amounts. Known as "alumina," aluminum compounds were used to prepare medicines in ancient Egypt and to set cloth dyes during the Middle Ages.

Aluminum numbers among the most abundant elements: after oxygen and silicon, it is the most plentiful element found in the earth's surface, making up over eight percent of the crust to a depth of ten miles and appearing in almost every common rock. However, aluminum does not occur in its pure, metallic form but rather as hydrated aluminum oxide (a mixture of water and alumina) combined with silica, iron oxide, and titania.

However, standing water in the presence of certain salts and caustics can be corrosive. For example, some hygroscopic products packaged in aluminum foil may cause some reaction, particularly if the product contains salt, or salt and some mild organic acid. In these or any other applications which may subject the aluminum foil to mild attack, coating or lamination protection is employed on the foil surface next to the product.