Four Common Filling Methods for Liquid Filling Machines

1. Atmospheric filling method

Atmospheric pressure filling method refers to atmospheric pressure, relying on the liquid’s own weight into the packaging container, the entire filling system is in an open state of work, atmospheric pressure filling method is the use of a liquid level to control the filling. The workflow is:
● A. Inlet and exhaust, the liquid is poured into the container, while the air inside the container is discharged from the exhaust pipe.
● B. After the liquid material in the container reaches the quantitative requirement, the liquid feeding is stopped and the irrigation is automatically stopped.
● C. Exhaust residual liquid, clear the residual liquid material into the exhaust pipe, ready for the next filling and discharge.
The atmospheric pressure filling method is mainly used for filling soy sauce, milk, white wine, vinegar, juice, and other liquid products with low viscosity, no carbon dioxide, and no odor.

2. Isobaric filling method

The isobaric filling method is to use the compressed air in the upper air chamber of the storage tank to fill the container first so that the pressure in the storage tank and the container is close to equal. In this closed system, the liquid substance flows into the container through its own weight. It is suitable for inflating liquids. Its working process:
● A. Inflation is equal to the pressure
● B. Inlet and return gas
● C. Stopping the liquid
● D. Release pressure (release the pressure of the remaining gas in the bottle to avoid a sudden drop in bottle pressure, resulting in bubbles and affecting the dosing accuracy)

3. Vacuum filling method

The vacuum filling method is to uses the pressure difference between the liquid being filled and the exhaust port to suck out the gas inside the container for filling. The pressure difference can make the flow of the product greater than the equal pressure filling. It is particularly suitable for filling small mouth containers, viscous products, or large-capacity containers with liquids. However, vacuum filling systems require overflow collection devices and product recirculation devices. Due to the different forms of vacuum generation, a wide variety of differential pressure filling methods are derived.

● A. Vacuum filling methods with low gravity
The container needs to be maintained at a certain vacuum level and the container needs to be sealed. Low vacuum levels are used to eliminate overflow and backflow during vacuum filling and to prevent the misfiling of gaps and interstices. If the container does not reach the required vacuum level, no liquid will flow from the filling valve opening and filling will automatically stop when a gap or crack in the container is encountered. The liquid product in the reservoir flows into the bottle through the fine sleeve valve, and the pipe in the center of the sleeve valve can be used for venting. When the container is automatically sent to rise under the valve, the spring in the valve opens under pressure and the pressure in the bottle equals the low vacuum in the upper part of the reservoir through the venting pipe and gravity filling begins. Filling stops automatically when the liquid level rises to the vent. This method rarely causes turbulence and does not require aeration, making it particularly suitable for filling wine or alcohol. The alcohol concentration remains constant and the wine does not overflow or backflow.

● B. Pure vacuum filling method
When the pressure in the filling system is below atmospheric pressure, the filling valve sealing block is directed towards the container and the valve is opened at the same time. As the container connected to the vacuum chamber is in a vacuum, the liquid is rapidly drawn into the container until the intended liquid has been filled. Some. Usually, a considerable amount of liquid is pumped into the vacuum chamber, into the overflow and then recycled.

The process flow of the vacuum filling method is 1. vacuum container 2. inlet and exhaust 3. stopping the inflow 4. remaining liquid return (the remaining liquid in the exhaust pipe flows back through the vacuum chamber to the storage tank).

The vacuum filling method increases the filling speed and reduces the contact between the product and the air, which helps to extend the shelf life of the product. Its fully closed state also limits the escape of active ingredients from the product.

The vacuum method is suitable for filling liquids with high viscosity (e.g. oil, syrup, etc.), liquid materials that are not suitable for contact with vitamins in the air (e.g. vegetable juice, fruit juice), toxic liquids (e.g. pesticides, chemical liquids), etc.

4. Pressure filling method

The pressure filling method is the opposite of the vacuum filling method. The can sealing system is at a higher than atmospheric pressure, with positive pressure acting on the product. Liquid or semi-fluid liquids can be filled by pressurizing a reserved space at the top of the storage box or by using a pump to push the product into the filling container. The pressure method keeps the pressure at both ends of the product and the vent above atmospheric pressure and has a higher pressure at the end of the product, which helps to keep the CO2 content of some drinks low. This pressure valve is suitable for filling products that cannot be vacuumed. For example, alcoholic beverages (the alcohol content decreases with increasing vacuum), hot drinks (90-degree fruit juices, where vacuuming would cause the drink to evaporate rapidly), and liquid materials with a slightly higher viscosity (jams, hot sauces, etc.).

Post time: Apr-14-2023