4 Most Common Liquid Filling Methods of Filling Machines

liquid filling methods


High pressure is essential for the liquid filling machine‘s liquid filling methods to be effective. This process is known as liquid pressure filling, and it occurs when the pressure in the reservoir is equal to the pressure in the bottle. This allows the liquid to flow into the container according to its own weight.

4 Most Common Liquid Filling Methods of Filling Machines

🔵 Isobaric Filling 

Filling the container with compressed air from the storage tank’s top air chamber brings the pressure within the two containers nearly equal, a process known as isobaric filling. The liquid fills the container due to its weight in this closed system. For the inflation of liquids, it works well. How it operates

  • The pressure equals the inflation.
  • Gas intake and output
  • Liquid Stopping
  • Release residual gas pressure to avoid bottle pressure drops that might generate bubbles and affect dose accuracy.

🔵 Atmospheric Filling 

One way to fill containers is via atmospheric pressure, which uses the weight of the liquid to force it into place. All parts of the filling mechanism are operational and visible. By monitoring the level of the liquid, the atmospheric pressure filling technique may be used to regulate the filling process. Here it works;

  • The exhaust pipe releases the air within the container, and the inlet pumps liquid into the container.
  • When the amount of liquid in the container meets the requirements, the liquid feeding stops, and the irrigation process stops on its own.
  • Prepare for the next filling and discharge by releasing any remaining liquid into the exhaust pipe.

Many low-viscosity, odorless, carbon dioxide-free liquid items, including juice, wine, sauce, milk, vinegar, and many more, are ideal for the atmospheric pressure filling process.

🔵 Pressure Filling 

The opposite of vacuum filling is pressure filling. Above atmospheric pressure, the can sealing mechanism applies positive pressure on the product. To fill a storage container with a liquid or semi-fluid substance, you may use a pump to force the product into the container or pressurize an area at the top of the box. 

Pressure techniques enhance pressure at the finish and keep pressure at both ends of the product and the vent above atmospheric pressure, resulting in low CO2 concentrations in certain drinks. A pressure valve fills non-vacuumable products. Alcoholic drinks (vacuum decreases alcohol concentration), hot drinks (90-degree fruit juices evaporate fast), and thicker liquids.

🔵 Vacuum Filling 

To fill a container with gas, the vacuum filling technique draws on the pressure differential between the liquid and the exhaust outlet. The product flow may be higher than the equal pressure filling due to the pressure differences. It works well with liquids with a thick consistency, items with a tiny mouth, or containers with a huge capacity. 

Overflow collectors and product recirculators are necessary components of vacuum filling systems. A wide range of differential pressure-filling techniques have grown from the various vacuum-producing techniques.

 A. Low Gravity Vacuum Filling

Sealing the container and keeping it at a certain vacuum level is important. When vacuum filling, it is crucial to maintain a low vacuum level to avoid overflow and backflow and misfiling spaces and gaps. The filling valve will not open to release liquid until the container achieves the necessary vacuum level, and the process will stop right away upon detection of a container break or gap. 

A fine-sleeve valve transfers the liquid product from the reservoir to the bottle, while a vent pipe sits in the middle of the valve. Gravity filling starts when the valve’s spring opens under pressure when the container is automatically directed to rise under it. This happens when the bottle’s pressure reaches the low vacuum in the reservoir’s top section via the venting line. 

When the liquid level reaches the vent, the filling process stops automatically. This technique is well for filling wines or liquor as it hardly creates instability and doesn’t need aeration. The wine doesn’t overflow or backflow, and the alcohol content stays the same.

 B. Full Vacuum Filling 

When the filling system pressure is below atmospheric, the filling valve sealing block faces the container and opens the valve. A vacuum draws liquid into the container linked to the chamber until it is full. Huge amounts of liquid are poured into the vacuum chamber, overflowed, and recycled.

The vacuum filling process speeds up filling and lowers product-air interaction, extending shelf life. Fully closed products prevent active substances from escaping. This vacuum technique is excellent for filling high-viscosity liquids like syrup, liquids that cannot be directly exposed to vitamins like fruit juice, hazardous liquids like pesticides, etc.

Liquid Filling System Methods

Which method is used for filling liquids?

Standard filling techniques include timed flow, level, weigh filling, and volumetric piston. Typically, these machines are rotational and have two carousels for filling and capping containers.

What are the methods for bottle filling?

Filling of liquid bottles. There are two types of machines available: volumetric and gravity fillers. While they work differently, they fill liquids like water, alcohol, and oil. For thicker liquids, the piston filler is the best option.

Which method is most often used while filling highly viscous liquids?

Pump and piston fillers are often the best options for very viscous materials. However, there are some exceptions. Conversely, thin, free-flowing goods could need gravity to provide a steady and dependable fill.

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