Two-piece tank refers to a metal container consisting of a whole seamless tank body with a lid and a bottom. The tank body of this kind of metal container is drawn to form a set shape. The forming method of cup container is stamping, so two-piece can is also called stamping tank.
In the 1940s, the British used stamping technology in the production of canned containers and produced shallow punching cans of aluminium alloy. Although this result is only a new application of traditional manufacturing technology, it has led to the change and development of the manufacturing technology of canned containers. Since then, the relevant companies in Britain and the United States have begun to study and improve the manufacturing technology and production process of aluminium stamping cans. The more famous companies are COORS and Reynolds (Reynolds) in the United States. In the 1960s, these companies successively developed such tank-making processes as DRD method and D&I method. At the same time, Aluminum Corporation of the United States (ALCOA) developed easy-to-pull cover manufacturing technology. The combination of these two technologies has opened up a broad market for aluminium cans, and promoted the improvement of aluminium cans manufacturing technology and the development of its manufacturing industry. In the 1970s, the manufacturing technology of two-piece cans was quite perfect and began to spread all over the world. In the 1970s, Japan, Europe and other countries and regions introduced two pieces of stamping tank production technology and equipment. In the 1980s, China began to introduce the production technology and production line of two stamping cans.
Aluminum is the second metal material in the production of metal container materials. Aluminum has the advantages of rich resources, light weight, easy processing and corrosion resistance. However, because the production process of aluminium consumes a lot of energy, the world's aluminium prices continue to rise, limiting the use of aluminium. To this end, many countries have launched a campaign to recycle aluminium cans (the theoretical value of energy consumption for recycling aluminium is only one tenth of that for smelting aluminium). At the same time, aluminium tank manufacturers are trying to improve the process and design of the tank, further reduce the thickness of the tank wall and the diameter of the lid, in order to save aluminium materials and reduce costs. Initially, the weight of the aluminium cans is about 20-22 kg per thousand. With the improvement of the properties of aluminium materials and the improvement of the manufacturing process, the weight of the aluminium cans is greatly reduced. According to relevant statistics, the weight of each thousand tanks has dropped from 18.8 kg in the 1960s to 15.4 kg in the 1970s and to 13.6 kg in the mid-1980s.
At the same time, people try to make two stamping cans with thin steel plates. After solving the technical problems in production, two stamping cans can be produced by tinplate and chrome plate (ECCS). Since the 1990s, the supply of aluminium materials has become increasingly tight and prices have been rising. At present, the cost of aluminium cans is about twice as high as that of steel cans, so most manufacturers are forced to switch to steel cans.