The knife is pried at the protruding point at the cover mouth, so that the external air can be opened after it enters the air pressure balance. Press the metal spoon out of the dent, and then just use the spoon to cut along this crack like a can knife. Pat the bottom of the can to make the objects inside the can shake violently to make molecular movement.

So that a small amount of gas enters the tank body, the air pressure is balanced, and the tank body is opened with a strong twist. Open the tin lid of the can and let one end of the spoon stand against the can lid. Let the back of the spoon stand against the can bottle. Then push down vertically. When you hear a bang, the can bottle can be opened easily.

Three sealing methods for tinplate cans:

1, high-temperature heating and exhaust, when packaging meat-based foods, the high temperature of 80-90 degrees Celsius is generally used to quickly exhaust air and seal it in a short time. For fruits and vegetables, the temperature of 60-75 degrees Celsius should be used for a long time until the tank reaches a suitable vacuum.

2, vacuum compressed air, when the food is about to be sealed, put it in a special vacuum sealing machine, and use the pressure in the vacuum to compress the air in the can. Vacuum treatment can also avoid the residue of bacteria and microorganisms, and this method is not limited by the heating of food, so it is one of the most used methods at present.

3. Steam expels air. This method expels the air in the tank by rapidly injecting steam into the package, and after the air is exhausted, the steam in the tube is condensed to achieve the vacuum effect. This method is more economical and convenient, but it is limited by the application of commodities.