Aluminum can
Encyclopedia : A : AL : ALU : Aluminum can
- Redirect
The aluminum can or aluminium can is a popular beverage can made of aluminum, first introduced by the Coors Brewing Company. Previous cans had been made of steel.
Modern cans are generally produced through a mechanical process that involves punching a flat blank from very stiff cold-rolled sheet. This sheet is typically alloy 3104-H19, which is aluminum with about 1% manganese and 1% magnesium to give it strength and formability. The flat blank is first formed into a cup about three inches in diameter. This cup is then pushed through a different forming process called "ironing" which forms the can. The bottom of the can is also shaped at this time. The malleable metal deforms into the shape of an open-top can. With the sophisticated technology of the dies and the forming machines, the side of the can is significantly thinner than either the top and bottom areas, where stiffness is required. One can-making machine can turn out about 500 cans per minute.
Finally, the top rim of the can is trimmed and pressed inward or "necked" to form a taper conical where the can lid will later be attached.
The lid contains a scored region and a pull tab that can be leveraged to open the hole (by pushing the scored region into the can). The lid for the can is usually an aluminum alloy with magnesium. Plain lids are stamped out from a coil of aluminum and are transferred to another press that converts them to easy-open ends. The conversion press forms an integral rivet button in the lid and scores the opening, while concurrently forming the tabs in another die from a separate strip of aluminum. The tab is pushed over the button which is then flattened to form the rivet that attaches the tab to the lid. The finished lids are shipped to the filling plant where they are attached to the can bodies after filling.
In 1963 Ermal Fraze of Dayton, Ohio invented the integral rivet and ring-pull tab for opening a can and received U.S. patent No. 3,349,949. These pull tabs were a common form of litter — and a lingering hazard for bare feet, especially at public beaches (as witnessed in the third verse of the Jimmy Buffett song "Margaritaville"). A further danger occurred when users dropped the tab into the can after opening it, and then drank from it; occasionally the sharp metal tab would be ingested or inhaled. The "stay-on tab" or "ecology end" was invented in the mid-1970's which eliminated the hazards of ring-pull tabs.
Because they are made of aluminum, these containers are very suitable for recycling. 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.
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. Aluminum is one of the few substrates that is cost effective to recycle. 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. The exact role (if any) of aluminum in Alzheimer’s disease is still being researched and debated. In aluminum cans internal coating is there to protect the aluminum from the contents and if the internal coating fails, the contents will create a hole and the can will leak with in a matter of days. There is some difference in taste, especially noticeable in beer, presumably only due to traces of the processing oils used in making the can. Oils used in can manufacturing are FDA approved and must be constantly monitored.
The first soft drinks to be sold in all-aluminum cans were R.C. Cola and Diet-Rite Cola (both made by the Royal Crown Cola company), in 1964.
A single empty 12-fluid-ounce aluminum can weighs approximately 15 grams, or 0.5 ounce. Therefore there are roughly 30 empty aluminum cans to an avoirdupois pound.
One problem with the current design is that the top edge of the can may collect dust or dirt in transit, if the can is not packaged in a completely sealed box. As illustrated here, some beverage makers have experimented with putting a separate foil lid on can tops as one solution. To help solve this problem, many marketers are shipping cans in cardboard 12 pack or 24 pack cases.
- In Russian local market are available strong alcohols (Vodka) in aluminium cans.
- In Japan canned fresh air is available, most popular in Tokio area.
- In Denmark local market aluminium cans are banned, its production is for export only.
See also
External links
- [self-heating coffee can]
- [History of the Aluminum Can]
- [External combustion engine made of aluminum can]
From Wikipedia, the Free Encyclopedia. Original article here. Support Wikipedia by contributing or donating.
All text is available under the terms of the GNU Free Documentation License See Wikipedia Copyrights for details.