Vacuum Packaging
Before many products are available for sale to the public,
they are packaged in some way. In the
food industry, most foods are vacuum packaged because they maintain their
freshness 3 to 5 times longer in comparison to other methods. Vacuum packaging, also known as reduced
oxygen packaging, involves placing a good, usually food, into a plastic
container, removing the oxygen and sealing it air-tight. There are many advantages to using this
method, including an extended shelf life, color retention, less shrinkage and
moisture control. It is mostly used by
food manufacturers to package foods such as cheese, potato chips and meat. Other industries that produce commercial
goods such as clothes might sometimes use vacuum packaging because it saves
space.
Products are vacuum sealed in thermoplastic material through
a simple 4 step process. For use in
factories, commercial-duty internal chamber vacuum sealers are used. These machines place the product, which is
inside an opened plastic bag, entirely inside.
The lid is closed, and a high-speed vacuum pump extracts air from the
entire chamber. The open portion of the
plastic has been placed on a heat strip, which seals the bag. The lid then opens, letting the air back
in. For fragile items such as potato
chips, many manufacturers use the gas-flush option, which flushes the vacuum
chamber with an inert gas such as nitrogen after the air is sucked out but
before the heat strip seals the plastic.
This causes the plastic not to be sucked down tightly, which happens in
normal vacuum packaging.