Sealing surfaces for container end panels

Abstract

A tubular container is provided with an angled sealing surface extending outwardly and downwardly around the upper periphery of the container. A flexible end panel, such as plastic film, metal foil, or thin plastic, or coated paper stock is heat or adhesively sealed to the angled surface of the container. This combination of container and end panel is particularly effective for food products and the like that are subjected to heat treatment, such as in a retort, following a filling operation of the container and sealing of the end panel thereto. The angled sealing surface retains the end panel in shear, rather than in peel, as the end panel bulges upwardly because of increased internal pressure. The integrity of the seal, at the interface of the container and the overlying end panel, is greatly enhanced.

1 . A container, said container comprising a tubular side wall terminating at an upper periphery thereof, an outwardly extending flange extending about said periphery and including a sealing surface thereon, said sealing surface being adapted for providing sealing engagement with a container end panel, characterized in that said sealing surface on said container extends radially outwardly and downwardly about said periphery for maintaining an interface of said end panel and said sealing surface in shear rather than peel.  
     
     
         2 . A container as defined in  claim 1  wherein said container is constructed of thermoplastic material.  
     
     
         3 . A container as defined in  claim 2  wherein said flange extends outwardly from said tubular side wall and includes a lower surface for being engaged by a sealing tool.  
     
     
         4 . A container as defined in  claim 1  wherein said flange includes an uppermost, horizontal sealing surface extending radially outwardly and joining with said outwardly and downwardly sealing surface.  
     
     
         5 . A container as defined in  claim 3  wherein said flange includes an uppermost, horizontal sealing surface extending radially outwardly and joining with said outwardly and downwardly sealing surface.  
     
     
         6 . A container as defined in  claim 3  wherein said lower surface ( 25 ) extends horizontally outwardly from said tubular side wall of said container.  
     
     
         7 . A container as defined in  claim 3  wherein said lower surface ( 125 ) extends downwardly and outwardly from said tubular side wall essentially parallel with said sealing surface.  
     
     
         8 . A container as defined in  claim 1  wherein said sealing surface and a peripheral portion of said end panel are located inwardly of an outermost edge ( 240 ) of said container side wall.