The metal cans currently used for packaging are mainly aluminum two-piece cans. Aluminum two-piece cans use aluminum alloy thin plates as materials, and thinning and drawing processes are used in the manufacturing process, so the thickness of the can walls is significantly thinner than the bottom of the cans. When used in beer packaging, strong internal pressure compensates for the rigidity of the thin tank wall. However, the high gas barrier, light-blocking, and tightness of metal cans will keep the quality of canned beer stable. It is also the existence of these metal features that allows metal cans to be filled at high speed even with the time-consuming filling method of isobaric filling.