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A method and apparatus for packaging food products provides evacuation of air and application of purging gas in two stages. The first stage evacuates air and applies an initial gas flush to a first group of packages while the second stage provides an evacuation of a portion of the gas initially appl

A method and apparatus for packaging food products provides evacuation of air and application of purging gas in two stages. The first stage evacuates air and applies an initial gas flush to a first group of packages while the second stage provides an evacuation of a portion of the gas initially applied and applies a second gas flush to the group and then seals the packages. The packages include food containing bases which enter the first stage station of the apparatus where lidding material is laid over a small leading portion of the group, and as this group is transported to the second stage station the lidding material is fed onto the remainder of the bases of the group. Each station includes an evacuation chamber having a base receiving cavity, the second station including base receiving dies acting in conjunction with a heater for bonding the lidding material to the bases. The cavity is closed after two groups of bases have been indexed into the cavity. After the evacuation and gas flush the dies are moved upwardly to force the group in the second station against the heater to bond the lidding material to the base. The cavity is thereafter opened so that the group of bases in the second stage may be removed and the group in the first stage may be indexed to the second stage while a third group is indexed into the first stage.

대표청구항 ▼

A method of forming hermetically sealed food containing packages having a base including at least one food containing cavity open at the top thereof and having a peripheral web including an upper surface disposed about the top of said cavity, said method comprising feeding to a first station of a ch

A method of forming hermetically sealed food containing packages having a base including at least one food containing cavity open at the top thereof and having a peripheral web including an upper surface disposed about the top of said cavity, said method comprising feeding to a first station of a chamber a group of bases interconnected at adjacent peripheral webs forming a gas barrier preventing leakage between the exterior of said bases beneath said webs and each cavity, closing said chamber to isolate said exterior of said bases beneath said webs from each cavity, communicating a subatmospheric pressure to the exterior of said bases beneath said web, applying an inert gas into each cavity to flush said cavities, thereafter communicating a subatmospheric pressure to each cavity to remove a substantial amount of the gas together with air and impurities from each cavity, again applying an inert gas to each cavity, releasing the subatmospheric pressure at the exterior of said bases beneath said webs, equalizing the pressure in said cavities with the pressure at the exterior of said bases beneath said webs, opening said chamber, laying a lidding material over the upper surfaces of said webs and transporting said bases to a second station of said chamber, closing said chamber to isolate said exterior of said bases beneath said webs from each cavity, communicating a subatmospheric pressure to the exterior of said bases beneath said webs, applying an inert gas into each cavity between said lidding material and said upper surface of said webs to flush said cavities, thereafter communicating a subatmospheric pressure to each cavity to remove a substantial amount of gas together with a substantial amount of the remaining air and impurities from each cavity, again applying an inert gas into each cavity between said lidding material and said upper surfaces, bonding said lidding material to said upper surfaces about said cavities to seal said cavities, releasing the subatmospheric pressure at the exterior of said bases beneath said webs, equalizing the pressure above said upper surface with the pressure at the exterior of said bases beneath said webs, and opening said chamber to remove said bases.