Repturable opening for sealed container

Abstract

A container formed from a paperboard laminate and including a rupturable opening for gaining access to the contents of the container, the opening being defined by an embossment pattern in a wall of the container. The embossment defines a weakened area which includes the layers of the laminate, but without destruction or deterioration of selected ones of the barrier/sealing layers of the laminate. A method is disclosed.

1 . In a container formed from a laminate having a paperboard layer and a layer serving as a barrier layer, or as a sealing layer, or as both a barrier and sealing layer material on at least one of the opposite surfaces of the paperboard layer, the container having a top end, the improvement comprising 
 a structurally weakened area defined in association with a wall of the container,    said weakened area being defined by at least first and second generally elongated embossments which intersect one another,    each of said embossments having a curved transverse cross-sectional geometry which includes each of the layers of the laminate intact, and defining a weakened area for rupture thereof upon the application of a rupturing force in the nature of a drinking straw urged against said weakened area in the approximate location of the intersection of said at least first and second generally elongated embossments.    
   
   
       2 . The improvement of  claim 1  wherein said cross-sectional geometry of each of said at least first and second intersecting embossments is substantially constant in geometry over its cross-sectional area.  
   
   
       3 . The improvement of  claim 2  wherein said intersection of said at least first and second elongated embossments defines an area of weakened resistance to rupture of said laminate at said intersection which is substantially less than the resistance to rupture of either of said at least first and second embossments at locations laterally displaced from said intersection thereof.  
   
   
       4 . The improvement of  claim 1  wherein each of said embossments projects outwardly of said container and beyond the plane of an outer surface of said laminate.  
   
   
       5 . The improvement of  claim 4  wherein each of said embossments projects beyond the plane of an outer surface of said laminate by a distance not greater than about the wall thickness of the container.  
   
   
       6 . The improvement of  claim 1  wherein said laminate includes a layer of polyethylene on each of the opposite surfaces of said laminate.  
   
   
       7 . The improvement of  claim 6  wherein said embossments do not destroy the continuity of said polyethylene layers on said laminate.  
   
   
       8 . The improvement of  claim 1  wherein said embossments are substantially linear.  
   
   
       9 . The improvement of  claim 1  wherein all layers of the laminate remain functionally intact.  
   
   
       10 . The improvement of  claim 1  wherein said at least first and second embossments structurally weaken said laminate in the area of said embossments.  
   
   
       11 . The improvement of  claim 1  wherein said weakened area exhibits a resistance to rupture of about 4.7 lbf applied to said weakened area by a drinking straw of about 4 mm diameter.  
   
   
       12 . The improvement of  claim 11  wherein said straw is of a polymeric material.  
   
   
       13 . A method for enhancing access to the liquid contents of a closed container formed from a paperboard laminate and having a top wall comprising the steps of 
 providing a pattern of embossments in a top wall of the container said pattern including at least first and second elongated embossments which intersect one another at least once along their respective lengths,    each of said elongated embossments having a curved substantially semi-circular cross-sectional geometry,    the locus of intersection of said embodiments defines a structurally weakened area having a lesser resistance to rupture than the remainder of said elongated embossments.    
   
   
       14 . The method of  claim 13  and including the step of positioning said embossment as projections from an outer surface of the laminate which defines the interior of the container.  
   
   
       15 . The method of  claim 14  wherein said embossments project from an outer surface of the laminate a distance not greater than the thickness of the top wall of the container.  
   
   
       16 . The method of  claim 14  wherein all layers of the laminate are retained intact.  
   
   
       17 . The method of  claim 14  wherein said weakened area exhibits a rupture resistance less than the rupture resistance of the remainder of said embossments.  
   
   
       18 . The method of  claim 17  wherein said weakened area exhibits a rupture resistance mean value of about 4.7 lbf applied to said weakened area by means of a 4 mm diameter drinking straw.  
   
   
       19 . The method of  claim 18  wherein said straw is of a polymeric material.  
   
   
       20 . A blank comprising: 
 a substrate having a plurality of score lines, the substrate configured to be folded along the plurality of score lines to form a sealed enclosure;    a structurally weakened area being defined on a portion of the substrate, the structurally weakened area comprises a plurality of embossments configured to be produced by a male die insert and a female die insert on opposed surfaces of the substrate, the structurally weakened area includes a thickness that is substantially less than a thickness of the substrate and wherein the structurally weakened area is configured to be ruptured upon applying a force thereto to permit access to an interior region of the sealed enclosure.    
   
   
       21 . The blank of  claim 20  wherein the substrate further comprises an inner surface and an outer surface, an inner layer of a polymer coated on the inner surface of the substrate, an outer layer of a polymer coated on the outer surface of the substrate wherein the inner and outer layers are configured to resist a force of about 4.7 lbf applied to the structural weakening area of the plurality of embossments.  
   
   
       22 . The blank of  claim 20  wherein the substrate further comprises an inner surface layer of polymer coated on the inner surface of the substrate and wherein the substrate is configured to resist a force of about 4.7 lbf applied to the structural weakening area.  
   
   
       23 . The blank of  claim 20  wherein the plurality of embossments further comprises shallow indentation embossments intersecting one another in the structurally weakened area and each shallow indentation embossments has a substantially semi-circular cross-sectional geometry.  
   
   
       24 . The blank of  claim 20  wherein the embossments project inwardly of the substrate and into the plane of the substrate.