The bottle cap is used to seal the bottle. According to different functions, there are bottle caps with different shapes and different operation methods. For example, the bottle cap of mineral water is round and twisted, the cap of cans is ring-shaped, and the cap of meat can is pulled. There is no fixed shape, and it is what it looks like when it is torn. The cap of the injection bottle is made of glass. It needs to be polished around the periphery with a grinding wheel and then popped open; the cap of the beer bottle that men like is to be pryed. The design of the bottle cap is all kinds of strange, and the designers have racked their brains to make it more innovative and attractive.