What Is Vacuum Filling Machinery?
Vacuum filling machinery is a type of equipment used in the packaging process, utilizing a vacuum to fill products, particularly useful for items prone to oxidation. For example, in the food industry, vacuum filling can stabilize the quality of food products by removing oxygen, thus preventing oxidation. A common example is the vacuum-sealed jars of jam, which are often difficult to open due to the vacuum inside.
Uses of Vacuum Filling Machinery
This machinery is predominantly used in the food industry to prevent food deterioration due to oxidation. Vacuum filling is an alternative to nitrogen displacement filling, where nitrogen is used to expel oxygen. While both methods aim to prevent oxidation, vacuum filling is generally less expensive than using nitrogen.
Principles of Vacuum Filling Machinery
Vacuum filling works by first evacuating the gas from the container, creating a low-pressure environment. When a vacuum is formed inside the container and a valve on the liquid side is opened, the pressure difference between the piping and the container causes the liquid to be drawn into the container. However, this method carries the risk of forming pinholes, which can lead to leaks.
There are two primary methods to create a vacuum in these machines:
- Vacuum Pumps: These use the rotational force of a motor. Types include pumps with rotating blades at an eccentric position and roots-type pumps with a cocoon-shaped rotating body.
- Ejectors: Ejectors utilize the Venturi effect, where a constricted structure allows air to pass through at high speed, creating a partial vacuum in the area.