Patent ID: 7458197

Claim:
A packaging system for packaging a food product, the packaging system comprising: a non-perforated lower web of flexible packaging material; a web transport conveyor transporting the non-perforated lower web from upstream to downstream locations through a series of stations, the series of stations comprising a loading station for placing the food product in a package defined by the lower web, a closing station for closing the package with an upper web of flexible packaging material, and a pasteurization station for pasteurizing the food product, the pasteurizing station located downstream of the loading station and upstream of the closing station; the pasteurization station comprising a pasteurization chamber defined by a lower chamber member located below the non-perforated lower web and an upper chamber member located above the non-perforated lower web; at least one of the upper and lower chamber members being movable towards and away from the other of the upper and lower chamber members into closed and open positions, respectively; wherein in the closed position, the upper and lower chamber members directly seal with and sandwich the non-perforated lower web therebetween, the non-perforated lower web and the upper chamber member defining the boundaries of a pocket in the pasteurization chamber for holding food; an entry port in the upper chamber member, the entry port configured to supply pasteurizing medium to the pocket when the upper and lower chambers are in the closed position; a supply of pasteurizing medium connected to the entry port; and an exit vent in the upper chamber member and spaced from the entry port, the exit vent being open to the pocket so as to receive and continuously vent pasteurizing medium that is supplied to the pocket via the entry port when the upper and lower chamber members are in the closed position; wherein the entry port and exit vent are configured such that during operation the pasteurizing medium passes into and out of the pocket without passing through the non-perforated lower web, without passing through an interface between the upper and lower webs, without passing between the upper and lower webs, and without the upper web in the pasteurization cavity.