Vacuum Packaging Machines are used for vacuum-packing (5-10mmHg) with materials that are highly resistant to air permeation, in order to preserve foodstuffs or tightly packaged products.
Most Vacuum Packaging Machines seal product bags in a vacum chamber.These type of machines take time to complete a cycle of packaging process, in which the bag is put in the chamber , the chamber sealed and vacuumized, and the bag heat-sealed and taken out after breaking vacuum in the chamber.With semi-automatic machines,several or a dozen bags can be vacuum-packaged at a time,whereas with a fully-automatic machines,product filling, dearating, sealing and discharging are done in sequence with higher efficency using several rotatively moving vacuum chambers.
Deep-drawn Vacuum Packaging Machines are widely used for packaging ham and sausage.The machines feed composite film such as nylon/PE, etc. from a roll stock at the bottom ,heat the film to form molds,put slices of ham,sausage, etc. in the molds, cover them with heat sealable film fed from above and seal by heat.
Gas Flush Vacuum Packaging Machines also are vacuum packaging machines.They replace air in a package with carbolic scid gas,nitrogen gas, etc., producing a package not squeezed tightly.There are two types of popular Gas Flush Vacuum Packaging Machines.One flushes gas into a package after removing air in it in the same way as a vacuum packaging machine, and the other sends gas into a package before or while filling it with products, thus sending out the air inside.Highly practical and popular among the latter type is one made up of a flexible package form, fill and seal machine or a sealing machine plus gas flushing pipe and other related device.
(Source:Japan Packaging Machine Guide.)