Headspace sealing and displacement method for removal of vacuum pressure

Abstract

A container ( 1 ) is intended for filling with a hot liquid ( 21 ). The container ( 1 ) has a neck finish ( 2 ) with an opening closed off by a primary seal ( 4 ) which has an expandable side wall ( 4 a ). As the liquid ( 21 ) cools, the side wall ( 4 a ) is drawn into the container ( 1 ) to remove vacuum pressure created within the container ( 1 ). A permanent cap ( 25 ) can provide a secondary seal for the container and define a secondary headspace ( 24 b ) between the primary and secondary seals ( 4 ) ( 25 ). In other embodiments the seal ( 4 ) can be replaced by a mechanically movable seal which may be locked in its downward position. Also the secondary seal can be provided with a port or aperture to provide access into the secondary headspace for a commodity. Also a commodity such as a tablet or pill may be provided within the secondary headspace.

1 - 22 . (canceled) 
   
   
       23 . A container having an upper portion with an opening into said container and a base, said upper portion having a neck finish which includes an expandable and moveable seal, wherein the seal is configured to be expandable and moveable relative to the container when sealed thereto and when a heated liquid is in the container, said seal moving downwardly towards the base and within the neck finish to compensate for vacuum forces during cooling of the liquid following sealing of the container, wherein said seal, to enable its downward movement, is selected from either of a flexible material having an expandable side wall, or a flexible balloon structure which is able to expand within the neck finish. 
   
   
       24 . A container as claimed in  claim 23  wherein a surface of said seal extends transversely across the neck finish and moves further into the neck finish as the seal expands. 
   
   
       25 . A container as claimed in  claim 23  or  claim 24  wherein said seal is of said flexible material having an expandable side wall. 
   
   
       26 . A container as claimed in  claim 25  in which said side wall has a concertina construction providing for its expansion. 
   
   
       27 . A container as claimed in  claim 23  in which the seal includes a rim portion which can engage with a rim of the neck finish. 
   
   
       28 . A container as claimed in  claim 23  wherein said seal is of said flexible material having said expandable side wall and said seal provides a primary seal for the container, a secondary seal being provided for said neck finish over said opening into said container to define a secondary headspace between the primary and secondary seals. 
   
   
       29 . A container as claimed in  claim 28  in which a commodity is positioned within said secondary headspace. 
   
   
       30 . A container as claimed in  claim 29  in which said commodity is one of a tablet and a pill intended for mixing with the liquid before use. 
   
   
       31 . A container as claimed in  claim 28  in which said secondary seal includes one of an aperture and a port to provide access into said secondary headspace. 
   
   
       32 . A container as claimed in  claim 31  in which one of said aperture and said port allows ingress of outside air into said secondary headspace and closes off following sufficient cooling of the liquid. 
   
   
       33 . A container as claimed in  claim 31  in which one of said aperture and said port enables the entry into the secondary headspace of a commodity. 
   
   
       34 . A container as claimed in  claim 33  in which the commodity is an oxygen-scavenging agent. 
   
   
       35 . A container as claimed in  claim 23  in which the seal is of said flexible balloon structure which expands within the neck finish in compensating for vacuum pressure as the liquid cools. 
   
   
       36 . A container as claimed in  claim 23  wherein said base inverts to provide a compression of the seal to move it within the neck finish towards the said opening and to pressurize a secondary headspace above said seal. 
   
   
       37 . A method of filling a container having a base and neck finish with a fluid which method includes introducing the fluid through an open end of the container so that it, at least substantially, fills the container, heating the fluid at least one of before and after its introduction into the container providing an expandable and moveable seal for the open end to cover and contain the fluid, said seal responding to the contraction of the fluid so as to compensate for pressure in a headspace of the container under the seal following sealing of the container, by moving downwardly towards the base and within the neck finish, wherein said seal, to enable its downward movement, is selected from either of a flexible material having an expandable side wall or a flexible balloon structure which is able to expand within the neck finish. 
   
   
       38 . A method of filling a container as claimed in  claim 37  in which said expandable side wall has a concertina construction.