Patent ID: 7328556

Claim:
A system for sealing thermoplastic bags, which system comprises: a platen conveyor with a platen conveyor travel path; a platen mounted on said platen conveyor and including a support adapted to receive thermoplastic film thereon; a dome conveyor with a dome conveyor travel path; a dome mounted on the dome conveyor and including a vacuum chamber; said platen and dome conveyor paths having contiguous portions whereat said dome is positioned over said platen and noncontiguous portions whereat said dome is not positioned over said platen; said dome having a raised position spaced above said platen and a lowered position on said platen whereby said vacuum chamber is enclosed along the contiguous portions of said travel paths; one of said dome and said platen having a sealing assembly sealing said bag with said dome in its lowered position, said sealing assembly including a liquid coolant source connected to said sealing assembly and cooling same; vacuum, sealing and ventilation stations in said conveyor travel path contiguous portions; a vacuum source connected to said vacuum chamber and activated at said vacuum station; said vacuum source being deactivated at said ventilation station; said platen conveyor travel path including a load area whereat products within bags are loaded on said platen upstream of said the contiguous conveyor travel paths; said dome conveyor travel path including a discharge area whereat said products and sealed bags are discharged from said platen; a drive mechanism including a drive motor and a drive shaft drivingly connected to said drive motor and to said conveyors; a sealing support assembly adapted to receive thermoplastic film thereon; a sealing bar assembly including a heated sealing bar; a heat source associated with said sealing bar and adapted for continuously heating same; said sealing bar assembly including first and second heat sink plates connected to the coolant source and positioned on opposite sides of said sealing bar in a thermal exchange relationship therewith; said sealing bar including a lower edge sealing surface and being movable between a raised position retracted relative to said heat sink plates and a lowered position relative to said heat sink plates with said sealing bar lower edge sealing surface engaging said thermoplastic film; each said heat sink plate including a respective lower edge of non-sealing contact surface; and said sealing bar assembly including a raised position with said heat sink plate lower edges of non-sealing contact surfaces spaced above said thermoplastic film and a lowered position with said heat sink plate lower edges of non-sealing contact surfaces engaging said thermoplastic film and clamping same against said sealing support assembly.