Beverage can

"Beer can" redirects here. For other uses, see Beercan (disambiguation).

"Pop cap" and "Pop top" redirect here. For the software companies, see PopCap Games and PopTop Software.

The stay-tab opening mechanism characteristic of most drinking cans since the mid-1980s. The 'wide-mouth' version, seen here, was introduced in the late 1990s.

A beverage can is a metal container designed to hold a fixed portion of liquid such as carbonated soft drinks, alcoholic beverages, fruit juices, teas, herbal teas, energy drinks, etc. Beverage cans are made of aluminum (75% of worldwide production) or tin-plated steel (25% worldwide production). Worldwide production for all beverage cans is approximately 370 billion cans per year worldwide.

History

See also: Tin can § History

Beginning in the 1930s, after an established history of success with storing food, metal cans were used to store beverages. The first beer was available in cans beginning in 1935 in Richmond, Virginia. Not long after that, sodas, with their higher acidity and somewhat higher pressures, were available in cans. The key development for storing beverages in cans was the interior liner, typically plastic or sometimes a waxy substance, that helped to keep the product's flavor from being ruined by a chemical reaction with the metal. Another major factor for the timing was the repeal of Prohibition in the United States at the end of 1933.

Canned beverages were factory-sealed and required a special opener tool in order to consume the contents. Cans were typically formed as cylinders, having a flat top and bottom. They required a can piercer, colloquially known as a "church key", that latched onto the top rim for leverage; lifting the handle would force the sharp tip through the top of the can, cutting a triangular hole. A smaller second hole was usually punched at the opposite side of the top to admit air while pouring, allowing the liquid to flow freely.

In the mid-1930s, some cans were developed with caps so that they could be opened and poured more like a bottle. These were called "cone tops", as their tops had a conical taper up to the smaller diameter of the cap. Cone top cans were sealed by the same crimped caps that were put on bottles, and could be opened with the same bottle-opener tool. There were three types of conetops: high profile, low profile, and j-spout. The low profile and j-spout were the earliest, dating from about 1935. The "crowntainer" was a different type of can that was drawn steel with a bottom cap. These were developed by Crown Cork & Seal (now known as Crown Holdings, Inc.), a leading beverage packaging and beverage can producer. Various breweries used crowntainers and conetops until the late 1950s, but many breweries kept using the simple cylindrical cans.

The popularity of canned beverages was slow to catch on, as the metallic taste was difficult to overcome with the interior liner not perfected, especially with more acidic sodas. Cans had two advantages over glass bottles. First for the distributors, flat-top cans were more compact for transportation and storage and weighed less than bottles. Second for consumers, they did not require the deposit typically paid for bottles, as they were discarded after use. Glass bottles deposits were reimbursed after consumers returned the empties back to the store.

By the time the United States entered World War II, cans had gained only about ten percent of the beverage container market; this was drastically reduced during the war to accommodate strategic needs for metal.

A pull tab from the 1970s.

In 1959, Ermal Fraze devised a can-opening method that would come to dominate the canned beverage market. His invention was the "pull-tab". This eliminated the need for a separate opener tool by attaching an aluminum pull-ring lever with a rivet to a pre-scored wedge-shaped tab section of the can top. The ring was riveted to the center of the top, which created an elongated opening large enough that one hole simultaneously served to let the beverage flow out while air flowed in. Pull-tab cans, or the discarded tabs from them, were also called "pop-tops" colloquially. In Australia these were colloquially known as "ring-pull". Into the 1970s, the pull-tab was widely popular, but its popularity came with a significant problem, as people would frequently discard the pull-tabs on the ground as litter, or drop them into the can and risk choking on them.

These problems were both addressed by the invention of the "push-tab". Used primarily on Coors Beer cans in the mid-1970s, the push-tab was a raised circular scored area used in place of the pull-tab. It needed no ring to pull up. Instead, the raised aluminum blister was pushed down into the can, with a small unscored piece that kept the tab connected after being pushed inside. Push-tabs never gained wide popularity because while they had solved the litter problem of the pull-tab, they created a safety hazard where the person's finger upon pushing the tab into the can was immediately exposed to the sharp edges of the opening. An unusual feature of the push-tab Coors Beer cans was that they had a second, smaller, push-tab at the top as an airflow vent — a convenience that was lost with the switch from can opener to pull-tab. The "push-tab" was introduced into Australia in the early 1980s and was locally known as "pop-tops".

The safety and litter problems were both eventually solved later in the 1970s with Daniel F. Cudzik's invention of the non-removing "Stay-Tab". The pull-ring was replaced with a stiff aluminum lever, and the removable tab was replaced with a pre-scored round tab that functioned similarly to the push-tab, but the raised blister was no longer needed, as the riveted lever would now do the job of pushing the tab open and into the interior of the can.

In 2008, an aluminum version of the crowntainer design was adopted for packaging Coca-Cola's Caribou Coffee beverage. In 2004, Anheuser-Busch adopted an all-aluminum bottle for use with Budweiser and Bud Light beers.

Standard sizes

Comparison chart of various standards
ml	imp fl oz	US fl oz
1,000	35.2	33.8
568	20	19.2
500	17.6	16.9
473	16.6	16
440	15.5	14.9
375	13.2	12.7
355	12.5	12
350	12.3	11.8
341	12.0	11.5
330	11.6	11.2
250	8.8	8.5
237	8.3	8.0
222	7.8	7.5
200	7.0	6.8
150	5.3	5.1

Capacity in countries

Various standard capacities are used throughout the world.

Australia

In Australia the standard can size is 375 ml. Energy Drinks are commonly found in 500 ml containers.

Brazil

In Brazil the standard can size is 355 ml.

New Zealand

In New Zealand the standard can size is 355 ml.

China

In China the most common size is 330 ml.

Can dimensions may be cited in metric or imperial units. Imperial dimensions for canmaking are written as inches+sixteenths of an inch (e.g. "202" = 2 inches + 2 sixteenths).

Europe

In Europe the standard can used to be 330 ml but since the 1990s the 250 ml size has slowly become about just as common. In European countries the 500 ml can size is second standard. It's often used for beer, cider and energy drinks.

In the UK 440 ml is commonly used for lager.

In Austria energy drinks are usually sold in sizes 200 to 300 ml. In 2014 for beverage cans in general, already much more aluminum is used than steel. There are even steel cans with alu-lids and vice versa.

Hong Kong

In Hong Kong most cans are 330 ml.

India

In India standard cans are 330 ml.

Japan

In Japan the most common sizes are 350 ml and 500 ml. Larger and smaller cans are also sold.

Korea

In Korea 250 ml cans are the most common for soft drinks. However, when accompanying take out food (such as pizza or chicken), a short 245 ml can is standard. Recently, some 355 ml cans which are similar to North American cans are increasingly available, but limited mostly to Coca-Cola and Dr Pepper. Finally, beer cans also come in 500 ml forms.

Malaysia and Singapore

In both Malaysia and Singapore, the most commonly found cans are 300 ml for non-carbonated drinks and 325 ml for carbonated drinks. Larger 330 ml/350 ml cans are limited to imported drinks where it would usually cost a lot more than local ones.

Pakistan

In Pakistan the most common sizes are 250 ml and 330 ml. 200 ml cans are also sold.

North America

In North America, the standard can size is . The US standard can is 4.83 inches high, 2.13 inches in diameter at the lid, and 2.60 inches in diameter at the widest point of the body.

In Canada, the standard size was previously 10 Imperial fluid ounces (284 ml), later redefined and labeled as 280 ml in around 1980. This size was commonly used with steel beverage cans in the 1970s and early 1980s. However, the US standard 355 ml can size was standardized in the 1980s and 1990s, upon the conversion from steel to aluminum. Some beverage such as Nestea are sold in 341 ml cans. In Quebec by the year 2015, a new standard for carbonated drink have been added as many important grocery store now only sell 6-packs (with plastic holds) with 222 ml cans instead of the original 341 ml (for the same price) and that from every major carbonated drinks. Many convenience stores began selling "slim cans" with a 310ml capacity as of late 2015

South Africa

South African standard cans are 330 ml (reduced in the early 2000s from the up-until-then ubiquitous 340 ml) and the promotional size is 440 ml. There is also the 500 ml can. A smaller 200 ml can is used for "mixers" such as tonic or soda water. It has a smaller diameter than the other cans.

Composition

Aluminum cans pressed into blocks for recycling

Most metal beverage cans manufactured in the United States are made of aluminum, whereas in some parts of Europe and Asia approximately 55 percent are made of steel and 45 percent are aluminum alloy. Steel cans often have a top made of aluminum. The aluminum used in United States and Canada are alloys containing 92.5% to 97% aluminum, <5.5% magnesium, <1.6% manganese, <0.15% chromium and some trace amounts of iron, silicon and copper according to MSDS from aluminum producer Alcoa. Alloys used include 3004, 3105, or other 3xxx/5xxx series aluminum.

An empty aluminum can weigh approximately half an ounce (13.5 g). There are roughly 30 empty aluminum 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 aluminum containers. Scrap metal dealers often purchase aluminum cans in bulk, even when deposits are not offered. Aluminum 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 aluminum requires large amounts of electricity, making recycling cheaper than producing new metal.

Aluminum cans are coated internally to protect the aluminum from oxidizing. Despite this coating, trace amounts of aluminum 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.

In order to achieve primary aluminum for manufacturing, bauxite needs to be converted to alumina through a Bayer process. After this process, aluminum can be extracted from alumina. Subsequently, it goes through a process called aluminum smelting and ingot casting. Simply, these two stages require alumina to undergo an extremely hot temperature and high-energy bath. Following this process is hot rolling and cold rolling. This is ultimately done to cast the aluminum can into shape for further processing. Finally, the process of “ironing” is performed which forms the shape of the can.

Filling cans

Cans are filled before the top is crimped on. The filling and sealing operations need to be extremely fast and precise. The filling head centers the can using gas pressure, purges the air, and lets the beverage flow down the sides of the can. The lid is placed on the can, and then crimped in two operations. A seaming head engages the lid from above while a seaming roller to the side curls the edge of the lid around the edge of the can body. The head and roller spin the can in a complete circle to seal all the way around. Then a pressure roller with a different profile drives the two edges together under pressure to make a gas-tight seal. Filled cans usually have pressurized gas inside, which makes them stiff enough for easy handling.

Fabrication process

Modern cans are generally produced through a mechanical cold forming process that starts with punching a flat blank from very stiff cold-rolled sheet. This sheet is typically alloy 3104-H19 or 3004-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.

Plain lids (known as shells) are stamped from a coil of aluminum, typically alloy 5182-H48, and transferred to another press that converts them to easy-open ends. This press is known as a conversion press which 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.

Opening mechanisms

Old beer can showing punches from a churchkey

Beer can pop-top display at a Budweiser Brewery

Early metal beverage cans had no tabs; they were opened by a can-piercer or churchkey, a device resembling a bottle opener with a sharp point. The can was opened by punching two triangular holes in the lid—a large one for drinking, and a second (smaller) one to admit air.

As early as 1922, inventors were applying for patents on cans with tab tops, but the technology of the time made these inventions impractical. Later advancements saw the ends of the can made out of aluminum instead of steel.

Cans are usually in sealed paperboard cartons, corrugated fiberboard boxes, or trays covered with plastic film. The entire distribution system and packaging need to be controlled to ensure freshness.

Pull-tab

Old style pull-tab in use on a can of Tsingtao beer in Beijing, China in 2009

Mikola Kondakow of Thunder Bay, Ontario, Canada, invented the pull tab version for bottles in 1956 (Canadian patent 476789). Then, in 1962, Ermal Cleon Fraze of Dayton, Ohio, United States, invented the similar integral rivet and pull-tab version (also known as ring pull in British English), which had a ring attached at the rivet for pulling, and which would come off completely to be discarded. He received US Patent No. 3,349,949 for his pull-top can design in 1963 and licensed his invention to Alcoa and Pittsburgh Brewing Company, the latter of which first introduced the design on Iron City Beer cans. 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.

The early pull-tabs detached easily. The Journal of the American Medical Association noted cases of children ingesting pull-tabs that had broken off and dropped into the can.

Full-top pull-tabs were also used in some oil cans and are currently used in some soup, pet food, tennis ball, nuts and other cans.

Stay-on-tab

A "standard" size can opening, once common in American soft drinks.

In 1975, Daniel F. Cudzik, an engineer with Reynolds Metals, filed a design patent application for a "End closure for a container." This later became known as a "Sta-Tab." When the Sta-Tab launched in 1975, on Falls City beer and, quickly, other beverages, there was an initial period of consumer testing and education. Cudzik later received patents for the "Easy Open Wall."US 3967752, issued 1976-07-06  US 3967753, issued 1976-07-06 . The validity of these patents was later upheld in litigation.

The similarly designed "Easy-open ecology end" was also invented by Ermal Fraze and Omar Brown. The patent application was filed also in 1975. This design reduced injuries and reduced roadside litter caused by removable tabs. The mechanism used a separate tab attached to the upper surface as a lever to depress a scored part of the lid, which folds underneath the top of the can and out of the way of the resulting opening.

Such "retained ring-pull" cans supplanted pull-off tabs in the United Kingdom in 1989 for soft drinks and 1990 for alcoholic beverages.

Wide Mouth

One of the more recent modifications to can design was the introduction of the "wide mouth" can in the late 1990s. The American Can Company, now a part of Rexam, and Coors Brewing Company have owned wide mouth design patent (number D385,192) since 1997. Other companies have similar designs for the wide mouth. Ball Corporation's from 2008 has a vent tube to allow direct airflow into the can reducing the amount of gulps during the pour.

Sustainable Beverage Ends

The SuperEnd from Crown Holdings launched in 2000 was designed to use 10% less metal in production than standard beverage ends.

Press button can

One variation was the press button can, which featured two pre-cut buttons—one small and one large—in the top of the can sealed with a plastic membrane. These buttons were held closed by the outward pressure of the carbonated beverage. The consumer would open the can by depressing both buttons, which would result in two holes. The small hole would act as a vent to relieve internal pressure so the larger button could then be pressed down to create the hole used for drinking the beverage. Consumers could also easily cut themselves on the edges of the holes or get their fingers stuck.

Press button cans were used by Pepsi in Canada from the 1970s to 1980s and Coors in the 1970s. They have since been replaced with pull tabs. Used in Australia, locally known as "pop-tops", for soft drinks during the early 1980s.

Full Aperture End

A recent innovation to the beverage can is the full aperture end, where the entire lid is removed turning the aluminum can into a cup. Crown Holdings first designed the "360 End" for use by SABMiller at the 2010 FIFA World Cup in South Africa. It has been used by Anheuser-Busch InBev in China and Brazil and most recently by Sly Fox Brewing Company in the United States.

Collecting

Beer can collecting was a minor fad in the late 1970s and 1990s. However, the hobby waned rapidly in popularity. The Beer Can Collectors of America (BCCA), founded in 1970, was an organization supporting the hobby, but has now renamed itself Brewery Collectibles Club of America to be more modern.

As of late 2009, membership in the Brewery Collectibles Club of America was 3,570, down from a peak of 11,954 in 1978. Just 19 of the members were under the age of 30, and the members' average age had increased to 59.

A collection of beverage cans in Dunsmuir, California

See also

• Beer Can Museum
• Beer Can Printing
• Beer koozie
• Beverage-can stove
• Self-heating can
• Six pack rings
• Widget (beer)

References

• Yam, K. L., "Encyclopedia of Packaging Technology", John Wiley & Sons, 2009, ISBN 978-0-470-08704-6
• Soroka, W., Fundamentals of Packaging Technology, IoPP, 2002, ISBN 1-930268-25-4

External links

• Beer can history
• Pull tab fundraiser myth
• Steel packaging (Steeluniversity)