Beverage can printing refers to the art and practice of applying an image to a metal beverage can, to advertise its contents.
History
The first beer sold in a can was in 1935, when a brewery in the United States inquired American Can Company about the possibility of packaging their beer in cans. In 1931, American Can Company began to experiment with the possibility of canned beer as they anticipated that the Prohibition period would soon end. The major obstacle in producing beer cans was that no current cans could withstand the excess pressure that was required in packaging beer. Two years later, American Can company successfully designed a coating that would prevent the beer from reacting with the tinplate cans.
Now that they developed a successful beer can, American Can Company had to pitch their innovation to breweries. While large breweries were skeptical of the unproven packaging method, the Gottfried Krueger Brewery took American Can Company's offer of free canning equipment in the event that canned beer was unsuccessful. The test results were extremely successful, and on January 24, 1935 in Richmond, Virginia, the first canned beer hit the public market as "Krueger’s Finest Beer." By the end of 1935, no less than 37 US breweries were producing canned beer.
Felinfoel Brewery Company, located at Llanelli, Wales, became the first brewery outside the United States to sell canned beer, and it was also a success. The package for this beer was called a "conetop". The interest in canned beer suddenly grew so fast that by 1937, 23 breweries were producing 40 brands of canned beer.
World War II temporarily stopped this innovation until 1952. By this point, most breweries were using flat top cans instead. From the 1950s to the 1960s, all beer can were composed from three pieces of metal. Two-piece cans hit the market in 1974. Throughout the years, innovative ideas and development slowly changed the beer can into what it is today. According to Ball Corporation, beer cans weighed 83 grams in 1951, and was then reduced to 38 grams by 1974, to what it is now today at only 21 grams.
Beer cans have been printed with colored photographic images since 1956, "first was famous Scottish and English landmarks and then with pinup girls", called the Lager Lovelies. These cans were popular all over the world. Extensive testing has been done with four color printing on the beers, but every attempt proved unsuccessful.
Coors examined many can coating curing methods and decided to implement an ultraviolet system, which they started to do in 1975. Coors is the only manufacturer to use the UV curing method in the United States. In 1986, they made further innovations to their UV coating lines to increase flexibility and efficiency.
Metal Box Company, a United Kingdom company, developed a method called "Reprotherm" for two-piece cans. In this process, the image to be printed is transferred to the can through a printed medium. Recently, a company called Nacano developed a six color printing method for two-piece cans, "but the first cans to be produced by this process have looked faded and washed out".
UV curing
Prior to the UV curing and coating system, Coors used a conventional production method. The production line is similar, but a four-color offset printer is used and a blanket lays the image onto the can as it spins on a mandrel. The cans are pulled into a gas convention oven by pin chains to cure the inks and varnishes, which take "12 seconds at 400 °F". Afterwards, an internal coating is applied to the cans and it is sent to another gas oven to be cured. Some of the problems using this thermal process of coating and curing includes: Speed of printing limited by length and speed of pin chain conveyors, high energy costs for gas ovens, and also the can coatings becoming non-functional, when they are overheated in the oven due to slow speed or stoppages. Also, the use of lubricants on the pin chains is kept to a minimum to prevent it from getting into the can. Because of this, pin chains "wear excessively and break frequently". Before it can even be repaired, 20 minutes need to be spent to wait for the oven to cool down enough.