The basic reason for using some aluminum for carbonated beverages cans is that it achieves a balance between lightness, strength and cost-effectiveness, and food safety and environmental requirements. According to the statistics from the American Aluminum Association, more than 75% of the world’s beverage can use “3003” and “5005” aluminum alloy, both materials’ density is lower than steel (3003 about 2.7g/cm³), the weight of a single can can be reduced by 65%-70%. For instance, Coca-Cola’s 100% recyclable tank only weighs 11.3 grams (Advances in Aluminum Processing Technology 2024).
Based on the durability analysis, 3003 aluminum alloy through cold rolling process can reach tensile strength of 1200psi, thickness only 0.18mm can bear internal pressure of the tank (equivalent to 3 meters deep water pressure), and 5005 due to added magnesium element, corrosion resistance increased by 30%, gap expansion rate under freezing condition is only 0.02mm/year. Much lower than the 0.1mm/year of conventional steel (International Aluminum Journal 2023).
On the aspect of cost saving in the manufacturing, 3003 aluminum conductivity is up to 37.7MS/m, and it can fulfill the needs of high-speed rolling forming machine, and the productivity efficiency is increased by 40% compared to the traditional steel tank, and the total cost of one tank is reduced by 22%. The production capacity of Nanshan Aluminum Industry, China’s leading aluminum profile enterprise, shows that its “extremely thin aluminum can” production line has a 99.3% yield, and 18,500 standard cans can be manufactured from one ton of raw materials (China Aluminum Industry Annual Report 2024).
Environmental regulations govern the material selection, in the European Union, recovery of drink cans to 95% by 2030 is obligatory, and aluminum because of its simple classification nature, purity of recycling can be maintained at over 98%. According to the U.S. Environmental Protection Agency, energy used in recycling one can of aluminum is the equivalent of electricity needed to power an American house for three months (Global Aluminum Cycle White Paper 2023). Additionally, after anodizing aluminum alloy 3003, the surface barrier performance increases 5-fold, thus possibly enhancing the drink shelf life for more than 2 years (Food Contact Material Safety Standard 2022).
Technological improvement continues to enhance the material advantage, i.e., “double-layer composite aluminum foil” produced by Boston Scientific, enhancing tank life for 15 years and suitable to store mineral water in harsh transit conditions (Frontiers in Materials Science 2024). Finally, the choice of “type of aluminum in soda cans” is the result of combined actions of material science, production process and environmental protection policy. In the future, with recycled aluminum content increasing to 75% (forecast 2030), the circular economy benefit of materials will be the main consideration indicator.