Vacuum packaging or vacuum packing is a packaging method that removes air from a package before sealing. Oxygen is removed from the package, and this extends the shelf life of foods. Food vacuum packaging limits the growth of fungi or aerobic bacteria and also prevents the evaporation of highly volatile components. The process is used to extend the life of foods such as smoked fish, potato chips, cured meat, cheese, cereals and nuts. It can also be used to store fresh foods like meats, liquids and vegetables. Food vacuum sealers are used to vacuum package food. The following are the different types of food vacuum sealers.
Single Vacuum Chamber Machines
With single chamber sealers, the entire food product is placed in the machine. Just like with external vacuum sealers, plastic bags are used for packaging. After the product has been placed in the machine, air is removed and the lid is closed. Inside the chamber lies a heat seal which seals the bag. After the bag has been sealed, it is refilled with air by a vent that opens to the outside. Single food vacuum sealers are used for packaging low-to-medium products, and can also vacuum seal liquids.
Double Vacuum Chamber Machines
With double chamber sealers, the entire food product is placed inside a plastic bag. After placing the product on the seal bar in the machine, the lid is then closed and air is sucked out. A seal bar inside the chamber then seals the product in the plastic bag. After sealing, the bag is then refilled with air. The oncoming pressure then squeezes out all the remaining air in the plastic bag. The lid is opened and the product removed. The lid swings from one side to the other, and this increases the speed of production as compared to the single chamber model. These food vacuum sealers are used for medium volume packaging. Double vacuum chamber packaging machines have either fully automatic lids or spring weighted lids.
Automatic Belt Vacuum Chamber Machines
With automatic belt chamber sealers, the entire food product is placed in a wrapped pouch or plastic bag within the machine. The product moves on the conveyor belt and is automatically positioned on the seal bar. The seal bar closes the lid and removes all the air. A seal bar inside the chamber then seals the bag. The lid is then opened and the product is removed. Automatic belt food vacuum sealers are used for high-speed packaging large items. The lid travels up and down. They are usually used for packaging large meat portions, processed meat and large sausage logs.
Thermoforming Vacuum Packaging Machines
Thermoforming machines are used for vacuum packaging large productions. These are form-fill-seal machines that package food using rolls of packaging film. The thermoformed pockets are filled with the products. The top web is then laid and sealed in vacuum. This results in the production of vacuum packaged products. Thermoforming greatly increases the speed of packaging production. You can customize thermoformed plastics for colour, clarity, size and shape so that the products fit perfectly as this creates a consistent approach.