The application history of the three-piece can has been nearly 200 years, although it has been improved many times, its basic composition is still made of three metal sheets (mostly tinplate) from the body of the can, the bottom of the can and the lid of the can, so it is named "three-piece can". Its shape, size and manufacturing method of the bottom and lid of the ordinary three-piece can are exactly the same, collectively referred to as the lid. There are two main sealing forms of the longitudinal seam of the tank body: tin welding and fusion welding. The former was used earlier, but it has been eliminated because of the lead in the solder. The latter can avoid lead pollution, low energy consumption, less material consumption, but the production equipment is complex.
The three-piece can has the characteristics of good rigidity, can produce cans of various shapes, high material utilization rate, easy to change size, mature production process, and many kinds of packaging products.