1. Superior physical properties
Light weight: The relative density of aluminum alloy is relatively low, making aluminum cans lighter and easier to carry and transport.
Good ductility: Aluminum alloy materials have good ductility and can be made into can bodies through multiple thinning and stretching to meet the manufacturing needs of aluminum cans.
Moderate hardness: Aluminum alloys have moderate hardness, which is not easy to deform or break, and improves the durability of aluminum cans.
2. Stable chemical properties
Strong oxidation resistance: Aluminum will form an oxide film (aluminum oxide Al2O3) on the surface in the air. This oxide film makes aluminum alloys not easily oxidized even at high temperatures, thereby ensuring the long-term performance of aluminum cans.
Good corrosion resistance: Aluminum alloy materials have good corrosion resistance to a variety of liquids (including carbonates in carbonated beverages), and will not corrode due to the presence of liquids.
3. Economic and environmental protection
Low cost: Aluminum raw materials are relatively abundant and easy to mine, and modern aluminum smelting technology has improved production efficiency, making the cost of aluminum alloys relatively low.
High recycling value: Aluminum cans have a high recycling value, and recycling can reduce resource waste and environmental pollution.
4. Other advantages
Good processing performance: Aluminum alloy materials are easy to process into various shapes and sizes to meet the different design requirements of aluminum cans.
Safety: Aluminum alloy materials are harmless to the human body (although excessive intake of pure aluminum is harmful to the human body, the content and form of aluminum in aluminum alloys usually do not cause direct harm to the human body), and are suitable for food packaging.
Due to the antioxidant properties of aluminum oxide Al2O3, even if aluminum cans are filled with liquid (liquids can form a solution of aluminum and oxygen to accelerate oxidation reactions), they will not rust like iron. Although carbonated beverages contain carbonate, aluminum is not easy to react with it. 5182 aluminum plate is used for the pull ring of aluminum cans.
At the same time, the relative density of aluminum alloy is relatively small. The mass of aluminum of the same volume is much smaller than that of iron. The aluminum cans in your hand are of course the lighter the better, and it is more convenient for everyone to hold; aluminum alloy is easy to recycle and environmentally friendly.
Aluminum has strong plasticity. By conveniently transforming into alloys with different other metals, the hardness, plasticity and even memory of aluminum have been greatly improved. Aluminum cans have good memory and generally do not deform when pinched in the hand. Most aluminum food packaging uses tin-aluminum alloy because it is easy to process, easy to tear off, and has high plasticity. It can be said to be a material with extremely wide applications.
The commonly used alloy material for pull rings of aluminum cans is 5182 aluminum plate. The main alloying element of 5182 alloy aluminum plate is magnesium, and a small amount of silicon is added. Therefore, the welding performance of welding 5182 aluminum plate with gas welding, argon arc welding, spot welding and roll welding is very good. As a high-magnesium alloy, 5182 aluminum plate for cans is a non-heat-treatable alloy with good strength, corrosion resistance, good machinability and other characteristics, and is widely used.
In summary, the use of aluminum alloy materials in aluminum cans is mainly based on its superior physical properties, chemical properties, economy and environmental protection. These advantages make aluminum alloy an ideal material for manufacturing cans.
