Bottom platen apparatus for forming skin packaging

Claim 1

In an apparatus for vacuum forming a skin package in which a closed chamber provides means for enabling the product which is to be packaged to be brought to a condition of reduced pressure at and during the time the product is being packaged, and in which upper and lower films are used to form the package surrounding the product said apparatus including: (a) a chamber of at least two portions and disposed to be opened for loading and closed for package forming, the closed chamber disposed to by its edges retain a warmed upper film as it is draped over and around the product being packaged; (b) a bottom platen disposed within the chamber and movable within determined limits to provide a loading position and an upper film-covering position; (c) means for heating the upper surface of the bottom platen at a portion intermediate its edges so as to condition the lower film for heat-sealing condition to the upper film; (d) means for cooling the upper surface of the bottom platen at the area peripheral to the heated portion so that the outer portions of the lower film which is supported by the lower platen and is within the chamber is maintained at a temperature which is less than the heat-sealing temperature of either of the films forming the package; (e) means for conducting atmospheric air, pressurized air, gas and the like from outside the closed chamber to at least one discharge point at the heated upper surface of the lower platen, and (f) conductors provided in the upper and lower chamber portions and selectively connected to sources of vacuum, air, gas and the like.

Claim 5

The method of forming a vacuum skin package in a chamber which is selectively closed so as to permit the interior of the chamber to be brought to a condition of reduced pressure and in this condition to permit a vacuum skin package to be formed between two films which provide the members forming the surrounding package, said method including the steps for: a. opening a chamber comprising of at least two mating parts; b. placing a lower film member on a lower platen movable in said chamber. c. placing the product to be packaged in said lower film member; d. moving an upper film over the product to be packaged and to the periphery of the chamber opening, said upper film being adapted for heat sealing to the bottom member when brought to a warmed condition; e. closing the chamber so as to cause the upper film to be gripped by the chamber members to cause the interior of the chamber to be divided by the upper film into upper and lower chambers; f. causing the entire interior of the upper and lower chamber portions and the product therein to be brought to a condition of reduced pressure by operatively connecting the upper and lower chamber portions to a source of vacuum; g. warming the bottom film in at least a selected area by means of a heating member in the lower platen so as to bring this area to a heat-sealing condition with the upper film; h. moving the upper film tOwards and around the product and towards the lower film by shutting off the operatively connected means from the upper chamber to the vacuum supply and operatively connecting said means to a source of air, gas and the like which is at a pressure at least substantially equal to atmospheric pressure; i. lifting the warmed bottom film from the upper surface of the lower platen by means of air, gas and the like which is also at least atmospheric pressure, said air, gas and the like being fed through a conductor so as to discharge at said upper surface of the platen and by its discharge move the lower film from the platen and snugly around the product and toward and to the upper film for heat sealing therewith, and j. opening the chamber to permit removal of the now packaged product from the chamber.

Claim 6

The method of forming a vacuum skin package in a chamber which is selectively closed so as to permit the interior of the chamber to be brought to a condition of reduced pressure and in this condition to permit a vacuum skin package to be formed between two films which provide the members forming the surrounding package, said method including the steps for: a. opening a chamber comprising of at least two mating parts; b. placing a lower film member on a lower platen movable in said chamber. c. placing the product to be packaged in said lower film member; d. moving an upper film over the product to be packaged and to the periphery of the chamber opening, said upper film being adapted for heat sealing to the bottom member when brought to a warmed condition; e. closing the chamber so as to cause the upper film to be gripped by the chamber members to cause the interior of the chamber to be divided by the upper film into upper and lower chambers; f. causing the entire interior of the upper and lower chamber portions and the product therein to be brought to a condition of reduced pressure by operatively connecting the upper and lower chamber portions to a source of vacuum; g. warming the bottom film in at least a selected area by means of a heating member in the lower platen so as to bring this area to a heat-sealing condition with the upper film; h. moving the upper film tOwards and around the product and towards the lower film by shutting off the operatively connected means from the upper chamber to the vacuum supply and operatively connecting said means to a source of air, gas and the like which is at a pressure at least substantially equal to atmospheric pressure; i. lifting the warmed bottom film from the upper surface of the lower platen by means of air, gas and the like which is also at least atmospheric pressure, said air, gas and the like being fed through a conductor so as to discharge at said upper surface of the platen and by its discharge move the lower film from the platen and snugly around the product and toward and to the upper film for heat sealing therewith, and j. opening the chamber to permit removal of the now packaged product from the chamber.