(1) Atmospheric pressure method
Atmospheric pressure method is also known as pure gravity method, that is, under atmospheric pressure, the liquid material flows into the packaging container according to its own weight. Most free flowing gasless liquid materials can be filled with this method, such as Baijiu, fruit wine, milk, soy sauce, vinegar and so on.
(2) Equivalent method
Isotropic method is also called pressure gravity filling method. Under the condition of high atmospheric pressure, the packing container is inflated to form the same pressure as that in the tank, and then the packing flows into the packing container according to its own weight. The method is widely used in the filling of beer and other aerated beverages.
This filling method can reduce the loss of carbon dioxide in the product and prevent excessive bubbles in the filling process from affecting the quality and quantitative accuracy.
(3) Vacuum method
The vacuum method is used for filling under the condition of lower than atmospheric pressure
a. Differential pressure vacuum type
That is to say, when the liquid storage tank is under normal pressure, only the packaging container is pumped to form a vacuum, and the liquid material is filled by the pressure difference between the storage tank and the container to be filled. This method is commonly used in China.
b. Gravity vacuum
That is to say, the liquid storage tank is in the vacuum packaging container. Firstly, it is pumped to form the same vacuum as the liquid storage tank, and then the liquid material flows into the packaging container by its own weight. Because of the complex structure, it is rarely used in China. Vacuum filling has a wide range of applications, which is suitable for filling liquid materials with slightly higher viscosity, such as oil, syrup, etc.
