Beverage Can - Composition

Composition

Most metal beverage cans manufactured in the United States are made of aluminium, whereas in some parts of Europe and Asia approximately 55 percent are made of steel and 45 percent are aluminium alloy. Steel cans often have a top made of aluminium. The aluminium used in United States and Canada are alloys containing 92.5% to 97% aluminium, <5.5% magnesium, <1.6% manganese, <0.15% chromium and some trace amounts of iron, silicon and copper according to MSDS from aluminium producer Alcoa.

An empty aluminium can weighs approximately half an ounce (15 g). There are roughly 30 empty aluminium cans to a pound or 70 to a kilogram.

In many parts of the world a deposit can be recovered by turning in empty plastic, glass, and aluminium containers. Scrap metal dealers often purchase aluminium cans in bulk, even when deposits are not offered. Aluminium is one of the most cost-effective materials to recycle. When recycled without other metals being mixed in, the can–lid combination is perfect for producing new stock for the main part of the can—the loss of magnesium during melting is made up for by the high magnesium content of the lid. Also, reducing ores such as bauxite into aluminium requires large amounts of electricity, making recycling cheaper than producing new metal.

Aluminium cans are coated internally to protect the aluminium from oxidizing. Despite this coating, trace amounts of aluminium can be degraded into the liquid, the amount depending on factors such as storage temperature and liquid composition. Chemical compounds used in the internal coating of the can include types of epoxy resin.