Modern cans are generally produced through a mechanical process that involves punching a flat blank. The malleable metal deforms into the shape of an open-top can, and the top portion of the cylinder may again be deformed in a conical shape. Jagged edges at the top are trimmed, and the container is filled with liquid. Finally, a top piece is affixed to the top of the can, containing a scored region and a pull tab that can be leveraged to open the hole.
Early beverage cans were opened by pulling a tab that completely removed a portion of the can's lid. These "pop top" tabs were a common form of litter--and a lingering hazard for bare feet, especially at public beaches--for many years until a new type of can was introduced.
Because they are made of aluminum, these containers are very suitable for recycling. In many parts of the world a deposit can be recovered by turning in empty plastic, glass, and aluminum containers. Unlike glass and plastic, aluminum cans are often purchased in bulk by scrap metal dealers, even when deposits are not offered. Their metal construction also conducts heat more readily than glass or plastic, and drinks in aluminum cans can be chilled more quickly than those in other containers.
Many consumers find the taste of a beverage from a can to be different from fountain drinks and beverages from plastic or glass bottles. Additionally, some people believe that aluminum leaching into the fluid contained inside can be dangerous to the drinker's health. [Disproved?]
A single empty 12 fluid ounce aluminum can weighs approximately 14.5 grams, or 0.51 ounces. Therefore there are about 31 empty aluminum cans to an avoirdupois pound.