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Aluminum can

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An aluminum can is a single-use container used for packaging many different products. Most cans feature an aluminum exterior and an interior coating made of polymer or epoxy resin. These containers are used for food items like soup and olives. They also hold beverages, oil, and various chemicals. Globally, production reaches 180 billion units every year. This volume makes the aluminum can the largest single use for aluminum on Earth.

Drinking can ring-pull tab
Drinking can ring-pull tab

The manufacturing process relies on the high malleability of aluminum. Malleability is the ability of a metal to be shaped without breaking. This property allows for the creation of a two-piece can. In this design, the body and the bottom are stamped from one piece. This is different from steel cans, which are often constructed from two separate pieces. Most cans are created through a process called "drawing" or "drawing and ironing." This involves shaping a flat plate or a shallow cup into a tall cylinder. Once the can is filled, a metal "end" is sealed onto the top. A sealing compound is added to ensure the container remains airtight.

To protect the contents, the interior of the can requires a special lining. Manufacturers spray an epoxy lacquer or polymer onto the inside surface. This coating serves two vital purposes. First, it prevents the aluminum from being corroded by acidic contents. Carbonated beverages are particularly acidic and could damage the metal. Second, the lining prevents the liquid from taking on a metallic taste. Some types of epoxy may contain a substance called bisphenol A. Finally, a label is added to the exterior. This is done by either printing directly on the metal or gluing a label to the curved surface.

Aluminum offers several advantages over traditional steel or tinplate cans. Aluminum is much lighter, which helps with transport and cost. It is also very easy to press into complex shapes. Unlike steel, aluminum does not rust. Furthermore, the development of easy-open ends has changed how people consume beverages. In 1962, the company Alcoa developed an easy-open aluminum end for the Pittsburgh Brewing Company. This invention is now used in nearly all of the canned beer market.

Drinking can ring-pull tab
Drinking can ring-pull tab

Recycling is a critical aspect of the aluminum industry. Cans are the most recycled beverage containers in the world, with a 69% global recycling rate. In 2012, Switzerland reached a 92% recycling rate for its aluminum beverage cans. However, significant waste still occurs. In 2017, the United States generated 3.8 million tons of aluminum. Of that amount, only 0.62 million tons were recycled, resulting in a 16% recycling rate. This means roughly $700 million worth of cans end up in landfills in the US annually. It is estimated that Americans throw away nearly $1 billion in wasted aluminum every year.

Greenville Public Works, ECVC Recycling Sorting facility - 14
Greenville Public Works, ECVC Recycling Sorting facility - 14

Recycling aluminum presents a specific technical challenge regarding metal alloys. The top of a can is made from a blend of aluminum and magnesium to increase its strength. When cans are melted down, this mixture is not suitable for making either the top or the bottom. To solve this, a new approach uses a process called annealing. Annealing allows for the production of an alloy that works for both parts of the can. Because aluminum is so versatile, the industry pays nearly $800 million a year for recycled material. Due to its durability and food-grade qualities, aluminum is also seen as a potential replacement for PET plastic bottles.

Beyond industrial use, aluminum cans are also popular items for collectors. Some people collect cans as a hobby, focusing on specific sectors like soda, beer, or oil. Cans often feature designs for films, musical albums, sporting events, or famous celebrities. For instance, tennis player Andre Agassi was featured on four Pepsi Max cans in 1996. Some collections are massive in scale. Davide Andreani holds a Guinness World Record for a collection of over 20,000 soda cans of one brand. Other notable collectors include Chris Cavaletti, who owned 12,402 Pepsi Cola cans, and Gary Feng, who collected 11,308 variations of Coca-Cola cans.

Greenville Public Works, ECVC Recycling Sorting facility - 14
Greenville Public Works, ECVC Recycling Sorting facility - 14
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