Packaging apparatus for making vacuum or gas-filled packages of the type including a flanged cup-shaped receptacle with a closure film sealed to the flanges and stretched down into the cup to engage and press against the product. The apparatus comprises a first packaging station where the film is sealed...http://www.google.com.au/patents/US4201030?utm_source=gb-gplus-sharePatent US4201030 - Packaging apparatus and techniques for forming closure tops
