Container Structure for Removal of Vacuum Pressure

Abstract

A hot-fill PET container or bottle ( 10 ) filling with a liquid at an elevated temperature has a side wall ( 9 ) extending to a lower portion including a pressure panel ( 11 ) and a base ( 21 ) in its unfolded or pre-fill position. The panel ( 11 ) is transversely oriented and has a decoupling or hinge structure ( 13 ), an initiator portion ( 1 ) and control portion ( 5 ) of a steeply angled inverting conical section between 30 and 45 degrees. The control portion enables the inversion of the panel ( 11 ) into the container ( 10 ) to compensate for vacuum or reduced pressure induced within the container as the liquid cools down. The base ( 2 ) can also have a plurality of reinforcing ribs ( 3 ).

1 . A container having a longitudinal axis, and comprising: an upper portion including an opening into the container; a sidewall portion extending from the upper portion to a lower portion, the lower portion including a standing support and a base, wherein the container includes a recessed instep adjacent to an inside border of the standing support; and a pressure panel located in the lower portion substantially transversely to the longitudinal axis, wherein the pressure panel is connected to the instep by a hinge structure, the pressure panel being movable substantially along the longitudinal axis between an initial position and an inverted position to compensate for a change of pressure induced within the container; wherein the pressure panel further comprises a centrally located push-up portion and a control portion, the control portion being inclined at an angle of more than 100 degrees relative to a plane parallel to the longitudinal axis, and the centrally located push-up portion being adapted to move in response to the change of pressure. 
     
     
         2 . The container of  claim 1 , wherein the pressure panel is adapted to move from the initial position to the inverted position under an externally applied mechanical force. 
     
     
         3 . The container of  claim 1 , wherein the pressure panel is adapted to move from the initial position to the inverted position in response to internal vacuum forces within the container. 
     
     
         4 . The container of  claim 2 , wherein the centrally located push-up portion is adapted to receive the mechanical force. 
     
     
         5 . The container of  claim 1 , wherein the centrally located push-up portion moves from an initial position to a position longitudinally further within the container. 
     
     
         6 . The container of  claim 5 , wherein movement of the centrally located push-up portion causes the control portion to invert. 
     
     
         7 . The container of  claim 6 , wherein the movement is a mechanical push-up force. 
     
     
         8 . The container of  claim 1 , wherein the centrally located push-up portion is recessed inwardly into the container. 
     
     
         9 . The container of  claim 1 , wherein the container structure is configured such that in use a top load applied to the container is transferred to the standing support. 
     
     
         10 . The container of  claim 1 , wherein the instep portion is recessed to such an extent the pressure panel is contained horizontally entirely above the standing ring prior to moving from the outwardly inclined position. 
     
     
         11 . The container of  claim 10 , wherein the container is adapted to contain a heated liquid and at least a portion of the sidewall is configured to deform under vacuum forces generated within the container during cooling of the heated liquid prior to the pressure panel being moved from the initial position to the inverted position. 
     
     
         12 . The container of  claim 11 , wherein movement of the pressure panel from the initial position to the inverted position reduces the internal volume of the container and reduces the deformation of the portion of the sidewall. 
     
     
         13 . The container of  claim 11 , wherein the body portion of the container further includes one or more ribs, the one or more ribs providing structural integrity for the plastic bottle. 
     
     
         14 . The container of  claim 1 , wherein the pressure panel includes a plurality of spaced apart outward projections, ribs or flutes. 
     
     
         15 . The container of  claim 1 , wherein the pressure panel includes a plurality of spaced apart inward projections, ribs or flutes. 
     
     
         16 . A method for handling, the method comprising: hot-filling the container with the pressure panel in the initial position, wherein the initial position is longitudinally away from the upper portion of the container; capping the container; creating a vacuum in the container by cooling; conveying the container having a vacuum created therein with the pressure panel in the initial position; and after said conveying, repositioning the pressure panel from the initial position to a second inverted position to reduce at least a portion of the vacuum, wherein the pressure panel remains above the standing support. 
     
     
         17 . The method of  claim 16 , wherein the body portion of the container further includes at least a portion of the sidewall configured to deform under vacuum forces generated within the container during cooling of the heated liquid prior to the step of moving the pressure panel from the initial position to the inverted position. 
     
     
         18 . The method of  claim 17 , wherein the body portion of the container further includes one or more ribs, the one or more ribs providing structural integrity for the plastic bottle. 
     
     
         19 . The method of  claim 16 , wherein the pressure panel is adapted to receive a mechanical device, and said repositioning the pressure panel includes operating the mechanical device to apply a force to reposition the pressure panel from the first position to the second position. 
     
     
         19 . The method of  claim 16 , further comprising blow molding the said container and the step of inverting the pressure panel about the hinge toward the interior of said container relative to the longitudinal axis. 
     
     
         20 . The method of  claim 19 , further comprising the step of inverting the pressure panel prior to filling the container. 
     
     
         21 - 25 . (canceled)