It is not possible for a small freezer (or any freezer) to vacuum seal itself shut every time you open it. Vacuum sealing occurs when the air inside a container is removed, creating a partial vacuum, which leads to a tight seal. Freezers are designed with a mechanism to release pressure, preventing them from sealing shut due to the vacuum effect.
When you open a freezer, the pressure inside the freezer is equalized with the external atmospheric pressure. The act of opening the door allows air to flow in and equalize the pressure, preventing a vacuum seal from forming.
However, it is not uncommon to experience some resistance when opening a freezer door that has been closed for an extended period. This resistance is due to the difference in temperature between the inside of the freezer and the surrounding air. As the cold air inside the freezer comes into contact with the warmer outside air, it can create a slight vacuum effect that makes the door feel stuck or difficult to open initially. But as soon as the door is opened, the pressure is equalized, and the vacuum effect is eliminated.
If you find that your freezer door is consistently difficult to open, there might be other issues to address, such as a faulty door seal or a mechanical problem. In such cases, it is advisable to have the freezer inspected and repaired by a qualified technician to ensure proper functionality.