Question Answer
0 View
Peringkat Artikel
1 звезда2 звезды3 звезды4 звезды5 звезд

What metal are Pepsi cans made of?

Do Coca-Cola cans and bottles contain BPA? | FAQ | Coca-Cola Canada

Bisphenol A (BPA) is a chemical used in thousands of materials, including some plastics. We use BPA in the linings of our beverage cans and in other packaging such as metal caps. The linings protect the quality and taste of the beverage inside.

Extensive reviews have been conducted by regulatory agencies not only in Canadabut also Australia, the European Union, Japan, New Zealand and the United States. These organizations include Health Canadaalong with the U.S. Food and Drug Administration (U.S. FDA) and European Food Safety Authority (EFSA).Each agency has determined the trace levels of BPA found in can linings poses no risk to consumers.

Why is BPA in Coke can liners?

BPA is a chemical used worldwide in making thousands of materials, including some plastics, coatings, and adhesives. Virtually all metal cans used for food and beverage products are lined on the inside with a coating that uses BPA as a starting material. This coating guards against contamination and extends the shelf life of foods and beverages.

BPA is also used in the manufacture of shatter-resistant bottles, medical devices (including dental sealants), sports safety equipment and compact disc covers. It has been used for more than 50 years.

We are aware that a limited number of metal can producers are using an older generation of can lining material as an alternative for some specialty products. Such alternatives do not work for the mass production of aluminum beverage cans, and they do not work for all types of food or beverages.

Are your products safe to consume if theyare in aluminum cans with liners containing BPA?

All of our products, regardless of the type of packaging used, are safe.

Independent scientists have thoroughly reviewed the data and have assured us that our beverage cans pose no public health risk.Ourown scientists also have reviewed the data and are confident about our packaging safety. In addition, the scientific body of evidence has been reviewed independently by several government regulators throughout the world. These regulators have repeatedlystated that current levels of exposure to Bisphenol A (BPA) through beverage packaging pose no health risk to the general population, including children.

Aluminum can liners that use BPA are the industry standard and have been used safely for more than 50 years. In fact, they have improved food and beverage safety by providing protection against food-borne diseases.

A number of studies and reviews conducted in 2010 and 2011, including one study lauded by a leading endocrinologist as being «majestically scientific and cautious,» support the prevailing evidence that BPA is safe for humans. Learn more about these studies.

Our top priority is to ensure the safety and quality of our products and packaging through rigorous standards that meet or exceed government requirements. If we had any concerns about the safety of our packaging, we would not use it.

Why do you maintain that the levels of BPA found in aluminum Coke cans are safe?

he clear scientific consensus is that there is no risk to the public fromthe miniscule amounts of BPA found in Coca-Cola or other beverage cans.

That consensus is accurately reflected in the opinions expressed by those regulatory agencies whose missions and responsibilities are to protect the public’s health.

Regulatory agencies in Canada,Australia, the European Union, Japan, New Zealand and the United States all have conducted extensive reviews and determined that current levels of exposure to BPA through food and beverage packaging do not pose a health risk to the general population. We believe it is reasonable and appropriate to take the lead from these agencies that regulate our business.

In 2010 and 2011, in response to the highly publicized controversy, some scientific and regulatory groups decided to undertake their own reviews of the existing literature.

The German Society of Toxicology reviewed the complete body of research –some 5,000 studies –and concluded that BPA exposure represents no noteworthy risk to the health of the human population.

The Japanese National Institute for Advanced Industrial Science and Technology; the World Health Organization/Food and Agriculture Organization (WHO/FAO); and the European Food Safety Authority (EFSA) also reviewed existing research in 2010 and came to the same conclusion. Learn more about the Japan,WHO/FAO and EFSA reviews.

EFSA issued a statement in December 2011 reaffirming its position after reviewing a report by the French Agency for Food, Environmental and Occupational Health and Safety (ANSES) on BPA. EFSA noted that its risk assessment (which includes a hazard assessment) was based on the question at hand —the safety of BPA from foods –whereas ANSES conducted a hazard assessment only, which included non-dietary exposure to BPA . Read the full EFSA opinion.

In addition, three new studies (described below), including one lauded by a leading endocrinologist as being «majestically scientific and cautious,» support the prevailing evidence that BPA is safe for humans.

Are you finding a replacement for liners containing BPA?

The Coca-Cola Company does not make aluminum cans or epoxy liners –but we are working with a number of packaging suppliers, leading-edge technology companies and research organizations that are developing possible alternatives. Any new packaging would have to meet both regulatory standards for safety and our requirements for safety, quality, taste and performance, so it is important that our chemists, toxicologists and packaging experts work closely with these parties.

While we have been asked numerous times to share more information about these efforts, information about status, timelines, materials and processes being evaluated is proprietary to our suppliers’ businesses and to their suppliers, and we are not in a position to divulge it.

While we believe our role in this process is important, the metal packaging industry is highly standardized and we are just one company involved in this process.

If you are convinced liners containing BPA are safe for Coke and other beverage cans, why are you working with your suppliers to look for alternatives?

We are confident that all of our packaging is safe. We also recognize that some of our consumers and shareowners have expressed concerns and initiated campaigns to legislate alternatives to can linings containing BPA. While we do not believe such action would be based on sound science, our continuous improvement efforts in this area will help ensure we are prepared for any eventuality so that we can protect our business and our consumers’ and shareowners’ interests.

I’ve read reports that your shareowners have submitted proposals asking you to eliminate BPA from your cans and you have refused to do so. Is that true?

No. The requests from a few of our shareowners, submitted as Shareowner Proposals at our2010 and 2011 Annual Meetings, were to create a report on our efforts at Coca-Cola to find an alternative to can liners with BPA. Our position relative to the production of such a report has been publicly available in our Proxy Statements,which can be accessed on our website.

It is also important to note that about 75 percent of the votes cast by our shareowners for the 2011 Annual Meeting were against the proposal for a report.

Beverage can

A beverage can (or drinks can) is a can manufactured to hold a single serving of a beverage. In the United States, the can is most often made of aluminum (almost entirely), but cans made in Europe and Asia are an alloy of approximately 55 percent steel and 45 percent aluminum. Aluminum is a widely available, affordable, lightweight metal that is easy to shape. Also, it is far more cost-effective to recycle aluminum than to extract it from its ores.


  • 1 Historical highlights
  • 2 Current characteristics
  • 3 Fabrication process
  • 4 Problems
  • 5 Recycling
  • 6 Gallery
  • 7 See also
  • 8 Notes
  • 9 References
  • 10 External links
  • 11 Credits

However, many consumers find that a drink from a can has a different taste compared to drinks from a fountain or glass bottle. Although an aluminum can has an internal coating to prevent the contents from directly contacting the aluminum, the internal coating occasionally fails, and the contents may then create a hole, causing the can to leak.

Historical highlights

The early metal beverage can was made out of steel (similar to a tin can) and had no pull-tab. Instead, it was opened by a can piercer, a device resembling a bottle opener, but with a sharp point. The can was opened by punching two triangular holes in the lid — a large one for drinking, and a small one to admit air. This type of opener is sometimes referred to as a churchkey. With further advancements, the ends of the can were made of aluminum instead of steel. Shasta claims to be the first soda company to can their beverages.

Early cans in the United States included what were known as cone tops and crowntainers, which had tops that were conical, rather than flat. Cone top cans were sealed by the same caps that were put on bottles. 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 same as the flat top cans that had to be opened with an opener. The crowntainer was a different type of can that was drawn steel with a bottom cap and the favorite of some collectors. Various breweries used crowntainers and conetops until the late 1950s, but not every brewery used every variety mentioned here. Crowntainers were developed by Crown Cork & Seal, now known as Crown Holdings, Inc., a leading beverage packaging and beverage can producer.

The first all-aluminum cans were the same as their forebears, which still used the can opener to open them. Mikolaj Kondakow of Thunder Bay, Ontario invented the pull tab version for bottles in 1956 (Canadian patent 476789). Then, in 1962, Ermal Cleon Fraze of Dayton, Ohio invented the similar integral rivet and pull-tab version (also known as rimple or ring pull), which had a ring attached at the rivet for pulling, and which would come off completely to be discarded. He received U.S. Patent No. 3,349,949 for his pull-top can design in 1963 and licensed his invention to Alcoa and Pittsburgh Brewing Company. It was first introduced on Iron City beer cans by the Pittsburgh Brewing Company. 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.

Pull-tabs were a common form of litter. Some users dropped the aluminum tab into the can and occasionally swallowed the sharp-edged tab by accident. Stay tabs (also called colon tabs) were invented by Daniel F. Cudzik of Reynolds Metals in Richmond, Virginia in 1975, [1] [2] partly to prevent the injuries caused by removable tabs. In this can model described in U.S. Patent No. 3,967,752, [3] 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. Stay tabs almost completely replaced pull-tabs in many parts of the world by the early 1980s, though pull-tabs are still common in places such as China and the Middle East.

One unsuccessful variation was the press-button can, which featured two pre-cut buttons, one large, one small, in the top of the can, sealed with a plastic membrane. These buttons were held closed by the outward pressure of the carbonated beverage. To open the can, the consumer would press both buttons into the body of the can, thus opening one through which to drink the beverage, the other to provide sufficient air to allow the contents to flow more easily. The buttons would remain attached to the can, alleviating the earlier issues with pull-tab ingestion. A disadvantage of this method was that a consumer could open a press button can and either remove, replace or taint its contents, before shaking the can enough to force the press buttons to re-seal the can, with little evidence of tampering. Another disadvantage was that it was too easy for consumers either to cut themselves on the sharp edge of either hole or get fingers stuck inside the can whilst pressing the buttons to open it.

Most beverage cans have a slightly tapered top and bottom. The metal on the lid of the can is significantly thicker than the metal on the sides. This means that a great deal of raw materials can be saved by decreasing the diameter of the lid, without significantly decreasing the structural integrity or capacity of the can.

The most recent advance in can design has been the «wide mouth» can: the opening was initially enlarged in the late 1990s by Mountain Dew. In 2000, Crown Holdings, Inc. introduced an improvement in beverage end technology, named SuperEnd. The geometry reduces the aluminum content by ten percent and creates a ‘billboard’ area, usable for brand logos and special messages.

Current characteristics

In North America, the standard can size (capacity) is 12 U.S. fluid ounces (355 ml/12.5 imp fl oz). In India and most of Europe, standard cans are 330 ml (11.6 imp fl oz/11.2 U.S. fl oz). In some European countries there is a second standard can size, 500 ml (17.6 imp fl oz/), often used for beer (roughly equal in size to the non-standard American 16 fluid ounce «tall boy,» also often used for beer). In Australia, the standard can size is 375 ml (/13.2 imp fl oz). South African standard cans are 340 ml (12.0 imp fl oz/), although the industry is (as of September 2007) converting to the European 330 ml standard and the promotional size is changing from 450 ml (15.8 imp fl oz/) to 440 ml (15.5 imp fl oz/).

Cans come in varying heights and diameters to encompass the range of capacities currently in use, but the diameters are usually one of two standard sizes. The United States, Australia, and New Zealand almost universally use a diameter slightly in excess of 65mm. This size is almost universal in these countries for soft drinks, beers, and ready-mixed spirit drinks. European countries mostly use a much narrower size of 52mm for soft drinks and some beers. Recently, the European size has started to appear in the US and Australasian markets with the appearance of energy drinks such as Red Bull (which is of European origin).

One practical difficulty brought about by these two differing standard sizes is that cans manufactured in Europe (with the smaller size cans and holders) and exported to the US or Australasia (who use the larger size) often present their owners with cup holders that are incapable of holding most drinks in those countries.

All metal beverage cans made in the United States are manufactured from aluminum, [4] whereas drink cans made in Europe and Asia are approximately 55 percent steel and 45 percent aluminum alloy.

An empty aluminum can weighs approximately a half-ounce (15 g). There are roughly 30 empty aluminum cans to an avoirdupois pound (450 g).

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 one percent manganese and one percent 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 forming machines, the side of the can is significantly thinner than either the top and bottom areas, where stiffness is required. One can-making production line can turn out up to 2400 cans per minute.

Plain lids are stamped out from a coil of aluminum, typically alloy 5182-H49, 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.

Finally, the top rim of the can is trimmed and pressed inward or «necked» to form a taper conical where the can will later be filled and the lid (usually made of an aluminum alloy with magnesium) attached.


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. Some marketers have experimented with putting a separate foil lid on can tops, and shipping cans in cardboard 12 or 24 pack cases.

Many consumers find the taste of a drink from a can to be different from fountain drinks and those from plastic or glass bottles. In addition, some people believe that aluminum leaching into the fluid contained inside can be dangerous to the drinker’s health. [5] The exact role (if any) of aluminum in Alzheimer’s disease is still being researched and debated, though the scientific consensus is that aluminum plays no role in development of the disease. [6] [7]

Aluminum cans contain an internal coating to protect the aluminum from the contents. If the internal coating fails, the contents will create a hole and the can will leak in a matter of days. There is some difference in taste, especially noticeable in beer, presumably due to traces of the processing oils used in making the can.


In many parts of the world, a deposit can be recovered by turning in empty plastic, glass, and aluminum containers. Unlike glass and plastic, 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 compensated by the high magnesium content of the lid. Also, the refining of ores such as bauxite into aluminum requires large amounts of electricity, making recycling cheaper than smelting.

Aluminum Beverage Can

Ninety-five percent of all beer and soft drink cans in the United States are made of aluminum. American can makers produce about 100 billion aluminum beverage cans a year, equivalent to one can per American per day. While almost all food cans are made of steel, aluminum’s unique properties make it ideal for holding carbonated beverages. The typical aluminum can weighs less than half an ounce, yet its thin walls withstand more than 90 pounds of pressure per square inch exerted by the carbon dioxide in beer and soft drinks. Aluminum’s shiny finish also makes it an attractive background for decorative printing, important for a product that must grab the attention of consumers in a competitive market.

Aluminum was first identified as an element in 1782, and the metal enjoyed great prestige in France, where in the 1850s it was more fashionable than even gold and silver for jewelry and eating utensils. Napoleon III was fascinated with the possible military uses of the lightweight metal, and he financed early experiments in the extraction of aluminum. Although the metal is found abundantly in nature, an efficient extraction process remained elusive for many years. Aluminum remained exceedingly high-priced and therefore of little commercial use throughout the 19th century. Technological breakthroughs at the end of the 19th century finally allowed aluminum to be smelted cheaply, and the price of the metal fell drastically. This paved the way for the development of industrial uses of the metal.

Aluminum was not used for beverage cans until after World War II. During the war, the U.S. government shipped large quantities of beer in steel cans to its servicemen overseas. After the war most beer was again sold in bottles, but the returning soldiers retained a nostalgic liking for cans. Manufacturers continued to sell some beer in steel cans, even though bottles were cheaper to produce. The Adolph Coors Company manufactured the first aluminum beer can in 1958. Its two-piece can could only hold 7 ounces (198 g), instead of the usual 12 (340 g), and there were problems with the production process. Nevertheless, the aluminum can proved popular enough to incite Coors, along with other metal and aluminum companies, to develop better cans.

The next model was a steel can with an aluminum top. This hybrid can had several distinct advantages. The aluminum end altered the galvanic reaction between the beer and the steel, resulting in beer with twice the shelf life of that stored in all-steel cans. Perhaps the more significant advantage of the aluminum top was that the soft metal could be opened with a simple pull tab. The old style cans required the use of a special opener popularly called a «church key,» and when Schlitz Brewing Company introduced its beer in an aluminum «pop top» can in 1963, other major beer makers quickly jumped on the band wagon. By the end of that year, 40% of all U.S. beer cans had aluminum tops, and by 1968, that figure had doubled to 80%.

While aluminum top cans were sweeping the market, several manufacturers were aiming for the more ambitious all-aluminum beverage can. The technology Coors had used to make its 7-ounce aluminum can relied on the «impact-extrusion» process,

The modern method for making aluminum beverage cans is called two-piece drawing and wall ironing, first introduced by Reynolds Metals company in 1963.

The modern method for making aluminum beverage cans is called two-piece drawing and wall ironing, first introduced by Reynolds Metals company in 1963.

where a punch driven into a circular slug formed the bottom and sides of the can in one piece. The Reynolds Metals company introduced an all-aluminum can made by a different process called «drawing and ironing» in 1963, and this technology became the standard for the industry. Coors and Hamms Brewery were among the first companies to adopt this new can, and PepsiCo and Coca-Cola began using all-aluminum cans in 1967. The number of aluminum cans shipped in the U.S. rose from half a billion in 1965 to 8.5 billion in 1972, and the number continued to increase as aluminum became the nearly universal choice for carbonated beverages. The modern aluminum beverage can is not only lighter than the old steel or steel-and-aluminum can, it also does not rust, it chills quickly, its glossy surface is easily imprintable and eye-catching, it prolongs shelf life, and it is easy to recycle.

Raw Materials

The raw material of the aluminum beverage can is, of course, aluminum. Aluminum is derived from an ore called bauxite. U.S. aluminum producers import bauxite, primarily from Jamaica and Guinea. The bauxite is refined and then smelted, and the resulting molten aluminum is cast into ingots The aluminum base, for beverage cans consists mostly of aluminum, but it contains small amounts of other metals as well. These are typically 1% magnesium, 1% manganese, 0.4% iron, 0.2% silicon, and 0.15% copper. A large portion of the aluminum used in the beverage can industry is derived from recycled material. Twenty-five percent of the total American aluminum supply comes from recycled scrap, and the beverage can industry is the primary user of recycled material. The energy savings are significant when used cans are remelted, and the aluminum can industry now reclaims more than 63% of used cans.

The Manufacturing

Cutting the blank

  • 1 The modern method for making aluminum beverage cans is called two-piece drawing and wall ironing. The process begins with an aluminum ingot which was cast to be about 30 inches (76 cm) thick, then rolled into a thin sheet. The first step in the actual manufacture of the can is to cut the sheet into a circle, called a blank, that will form the bottom and sides of the can. Each blank is 5.5 inches (14 cm) in diameter. Some material is necessarily

The small ripples at the top of the metal are called

The small ripples at the top of the metal are called «ears». «Earing» is an unavoidable effect of the crystalline structure of the aluminum sheet.

Redrawing the cup

  • 2 The small cup resulting from the initial draw is then transferred to a second machine. A sleeve holds the cup precisely in place, and a punch lowered swiftly into the cup redraws it to a diameter of about 2.6 inches (6.6 cm). The height of the cup increases simultaneously from the initial 1.3 to 2.25 inches (3.3 to 5.7 cm). The punch then pushes the cup against three rings called ironing rings, which stretch and thin the cup walls. This entire operation—the drawing and ironing—is done in one continuous punch stroke, which takes only one fifth of a second to complete. The cup is now about 5 inches (13 cm) high. Then another punch presses up against the base of the cup, causing the bottom to bulge inward. This shape counteracts the pressure of the carbonated liquid the can will contain. The bottom and lower walls of the can are also a little thicker than the upper walls, for added strength.

Trimming the ears

  • 3 The drawing and ironing process leaves the can slightly wavy at the top. These small ripples in the metal are called «ears.» «Earing» is an unavoidable effect of the crystalline structure of the aluminum sheet. Aluminum companies have studied this phenomenon extensively, and they have been able to influence the placement and height of the ears by controlling the rolling of the aluminum sheet. Nevertheless, some material is lost at this stage. About a quarter inch is trimmed from the top of the can, leaving the upper walls straight and level.

Cleaning and decorating

  • 4 The drawing and ironing process leaves the outer wall of the can with a smooth, shiny surface, so it does not require any further finishing such as polishing. After the ears are trimmed, the can is cleaned and then imprinted with its label. After the can is decorated, it is squeezed in slightly at the top to a make a neck, and the neck is given an out-ward flange at the very top edge, which will be folded over once the lid is added.

The lid

  • 5 The lid is made of a slightly different alloy than the aluminum for the base and sides of the can. The inward bulge of the bottom of the can helps it withstand the pressure exerted by the liquid inside it, but the flat lid must be stiffer and stronger than the base, so it is made of aluminum with more magnesium and less manganese than the rest of the can. This results in stronger metal, and the lid is considerably thicker than the walls. The lid is cut to a diameter of 2.1 inches (5.3 cm), smaller than the 2.6-inch (6.6 cm) diameter of the walls. The center of the lid is stretched upward slightly and drawn by a machine to form a rivet. The pull tab, a separate piece of metal, is inserted under the rivet and secured by it. Then the lid is scored so that when the tab is pulled by the consumer, the metal will detach easily and leave the proper opening. To ensure that the cans are made properly, they are automatically checked for cracks and pinholes. One in 50,000 cans is usually found to be defective.

Filling and seaming

  • 6 After the neck is formed, the can is ready to be filled. The can is held tightly against the seat of a filling machine and a beverage is poured in. The lid is added. The upper flange formed when the can was given its neck is then bent around the lid and seamed shut. At this point, the can is ready for sale.


Some aluminum is lost at several points in the manufacturing process—when the blanks are cut and the ears are trimmed—but this scrap can be reused. Cans which have been used and discarded by consumers can also be reused, and as mentioned above, recycled material makes up a significant percentage of the aluminum used for beverage cans. The savings from recycling are quite significant to the industry. The major expense of the beverage can is in the energy needed to produce the aluminum, but recycling can save up to 95% of the energy cost. Can producers also try to control waste by developing stronger can sheet so that less aluminum goes into each can, and by carefully controlling the manufacturing process to cut down on loss through earing. The lid of the typical can is smaller in diameter than the walls in order to conserve the amount of aluminum that goes into it, and as world-wide demand for beverage cans continues to grow, the trend is to make the lid even smaller. A new can introduced in 1993 with a lid a quarter-inch smaller in diameter than most cans can save manufacturers $3 per thousand. This figure seems small until it is multiplied by the hundreds of millions of cans produced each day in the U.S. It becomes clear that any small savings in raw materials or energy can be a major step in conserving both money and resources.

The Future

Worldwide production of aluminum beverage cans is steadily increasing, growing by several billion cans a year. In the face of this rising demand, the future of the beverage can seems to lie in designs that save money and materials. The trend towards smaller lids is already apparent, as well as smaller neck diameters, but other changes may not be so obvious to the consumer. Manufacturers employ rigorous diagnostic techniques to study can sheet, for example, examining the crystalline structure of the metal with X-ray diffraction, hoping to discover better ways of casting the ingots or rolling the sheets. Changes in the composition of the aluminum alloy, or in the way the alloy is cooled after casting, or the thickness to which the can sheet is rolled may not result in cans that strike the consumer as innovative. Nevertheless, it is probably advances in these areas that will lead to more economical can manufacture in the future.

Where To Learn More


Smith, George David. From Monopoly to Competition: The Transformations of Alcoa, 1888-1986. Cambridge University Press, 1988.


Hosford, William F. and John L. Duncan. «The Aluminum Beverage Can.» Scientific American, September 1994, pp. 48-53.

Larson, Melissa. «New Ideas Come In Cans.» Packaging, April 1993, pp. 30-31.

Singh, S. Paul. «Internal Gas Pressure on the Compression Strength of Beverage Cans and Plastic Bottles.» Journal of Testing and Evaluation, March 1993, pp. 129-31.

Angela Woodward

Ссылка на основную публикацию