Search results
Results from the WOW.Com Content Network
Main page; Contents; Current events; Random article; About Wikipedia; Contact us
External vacuum sealers involve a bag being attached to the vacuum-sealing machine externally. The machine will remove the air and seal the bag, which is all done outside the machine. A heat sealer is often used to seal the pack. Typically these units use a dry piston vacuum pump which is often considered a "maintenance-free" pump.
Diagram of a vacuum flask Gustav Robert Paalen, Double Walled Vessel. Patent 27 June 1908, published 13 July 1909 Patent 27 June 1908, published 13 July 1909 The vacuum flask was designed and invented by Scottish scientist James Dewar in 1892 as a result of his research in the field of cryogenics and is sometimes called a Dewar flask in his honour.