Vented closures

Abstract

Disclosed herein are a method of an apparatus for providing a vented closure ( 10 ) for a container having complementary non gas-tight features ( 52, 54 ) by which the closure may be removeably attached to close the container, by fitting a venting member ( 12 ) to form a liquid-tight, gas-venting seal between the closure and the container and provide a venting gas path from the container through the venting member to atmosphere via the complementary closure and container features; the venting member may replace or by-pass the existing sealing member in a closure.

1 . A method of providing a vented closure for a container, the closure and container having complimentary none gas-tight features by which the closure may be removeaby attached to close the container, characterised by fitting a venting member to form a liquid-tight, gas-venting seal between the closure and the container and provide a venting gas path from the container through the venting member to atmosphere via the complimentary closure and container features.  
     
     
         2 . A method of converting a sealed to a vented closure for a container, the closure and container having complimentary features by which the closure may be removeaby attached to close the container and a sealing member to form a fluid-tight seal between the closure and the container; characterised by replacing or by-passing the sealing member with a venting member to form a liquid-tight, gas-venting seal between the closure and the container and provide a venting gas path from the container through the venting member to atmosphere via the complimentary closure and container features.  
     
     
         3 . A method as claimed in  claim 1  or  claim 2 , characterised in that the venting member is microporous.  
     
     
         4 . A venting closure for a container, the closure ( 10 ) and container ( 48 ) having complimentary, none gas-tight features ( 52 ,  54 ) by which the closure may be removeaby attached to the container, characterised in that a venting member ( 12 ) is shaped and dimensioned to fit as a liquid-tight, gas-venting seal between a given closure ( 10 ) and container ( 48 ) and, in use, provide a venting gas path from the container through the venting member to atmosphere via the complimentary closure and container features ( 52 ,  54 ).  
     
     
         5 . A closure as claimed in  claim 4 , characterised in that the venting member ( 12 ) is a microporous member ( 24 ).  
     
     
         6 . A closure as claimed in  claim 4  or  claim 5 , characterised in that the complimentary closure and container features ( 52 ,  54 ) form an air-side labyrinth seal that, in use, acts to prevent passage of liquid to the venting member ( 12 ).  
     
     
         7 . A closure as claimed in any of  claims 4  to  6  and wherein the closure is a cap ( 14 ) and the container ( 48 ) has a neck ( 44 ), the cap and neck having the complimentary features ( 52 ,  54 ), characterised in that the venting member is an insert ( 12 ) for the cap ( 14 ).  
     
     
         8 . A closure as claimed in  claim 7 , characterised in that gas flow means ( 46 ) are provided between the insert ( 12 ) and the cap ( 48 ).  
     
     
         9 . A closure as claimed in  claim 8 , characterised in that the gas flow means is formed by projections ( 46 ) on a cap-facing surface of the insert ( 12 ).  
     
     
         10 . A closure as claimed in  claim 8  or  claim 9 , characterised in that the insert ( 12 ) is moulded from rigid plastics material to generally conform to the inner shape of the closure cap ( 14 ) and has a central aperture ( 16 ) closed on the liquid-side by a microporous membrane ( 24 ).  
     
     
         11 . A closure as claimed in  claim 10 , wherein the closure cap ( 14 ) has a depending sealing flange ( 40 ), characterised in that the insert ( 12 ) has a corrugated rim portion ( 34 ) with two concentric peripheral grooves ( 36 ,  38 ) respectively opening upwards, to accommodate and by-pass the cap sealing flange ( 40 ), and downwards, to accommodate the rim of the container neck ( 44 ).  
     
     
         12 . A closure as claimed in  claim 9  and  claim 10 , characterised in that the insert projections are formed by integral ribs ( 46 ) extending radially from the central aperture ( 16 ) to the rim portion ( 34 ).  
     
     
         13 . A closure as claimed in  claim 11 , characterised in that the cap-facing surfaces of said two concentric peripheral grooves ( 36 ,  38 ) are roughened to form venting gas flow means between the insert ( 12 ) and the cap ( 14 ).  
     
     
         14 . A closure as claimed in any of  claims 4  to  13 , further characterised in that the insert ( 12 ) has a liquid-side capillary port ( 28 ) that, in use, acts to permit passage of gas and prevent passage of liquid to the venting member ( 24 ).  
     
     
         15 . A closure as claimed in  claim 14  as dependent on  claim 10 , characterised in that a cup-shaped member ( 26 ) is mounted liquid-tight to the liquid side of the insert ( 12 ) with the microporous membrane ( 24 ) closing the mouth of the cup-shaped member; the capillary port ( 28 ) being formed in a wall of the cup-shaped member.  
     
     
         16 . A closure as claimed in any of  claims 4  to  15 , characterised in that the venting member ( 12 ) is designed to replace or by-pass a sealing member, forming a fluid-tight seal between the closure ( 10 ) and the container ( 48 ), and form a liquid-tight, gas-venting seal between the closure and the container.  
     
     
         17 . A venting member for a venting closure as claimed in any of  claims 4  to  16 .