Plastic closure, closure and container package, and method of manufacture

Abstract

A method of making a closure having an end panel and a sealing liner on one face of the end panel includes providing an injection mold having at least first and second mold elements, at least one of which is movable with respect to the other. The first and second mold elements are positioned to form a first mold cavity, and the end panel is injection molded within the first mold cavity. At least one of the first and second mold elements then is moved to form a second mold cavity in which a face of the end panel forms at least one mold cavity wall, and the sealing liner is injection molded onto the face of the end panel. The end panel and liner are then removed from the second mold cavity. The liner/disk subassembly thus is provided more easily and economically than if the liner were compression molded in situ onto the undersurface of a separately formed disk. The closure preferably is a two-piece closure, and the method preferably includes the step of assembling the end panel to a separately formed closure shell.

1 . A method of making a closure that includes an end panel of relatively rigid plastic construction and a sealing liner of relatively flexible resilient construction on one face of said end panel, said method including the steps of: 
 (a) providing an injection mold that includes at least first and second mold elements, at least one of which is movable with respect to the other,    (b) positioning said first and second mold elements to form a first mold cavity,    (c) injection molding said end panel of relatively rigid plastic construction within said first mold cavity,    (d) moving at least one of said first and second mold elements to form a second mold cavity in which a face of said end panel forms at least one mold cavity wall,    (e) injection molding said sealing liner of relatively flexible resilient construction on said face of said end panel, and    (f) removing said end panel and liner from said second mold cavity.    
   
   
       2 . The method set forth in  claim 1  wherein said steps (c) and (e) are carried out by injecting the panel and liner materials through laterally spaced gates.  
   
   
       3 . The method set forth in  claim 1  wherein said steps (b) and (c) are such that said end panel is imperforate.  
   
   
       4 . The method set forth in  claim 1  of making a two-piece closure that includes the step of assembling a separately formed closure shell to said end panel.  
   
   
       5 . The method set forth in  claim 1  of making a one-piece closure wherein said end panel is molded in said step (c) as a base wall of a one-piece closure shell.  
   
   
       6 . A plastic closure that comprises: 
 a plastic closure shell including a base wall with a central opening and a skirt for securing the closure to a container neck finish,    a plastic disk retained within said shell parallel to but separate from said base wall, said disk including a plurality of axially extending spacer elements around said disk to engage an underside of said base wall and space said disk from said base wall of said shell, angularly spaced fingers extending from said disk through said central opening of said base wall retaining said disk within said shell, and a resilient sealing liner molded in situ on an underside of said disk in a two-material molding operation for sealing engagement with a container neck finish.    
   
   
       7 . The closure set forth in  claim 6  wherein said spacer elements comprise a plurality of angularly spaced circumferentially aligned bead segments around a peripheral portion of said disk.  
   
   
       8 . The closure set forth in  claim 6  wherein said disk is free to rotate with respect to said shell.  
   
   
       9 . The closure set forth in  claim 6  wherein said disk has an axially extending circumferentially continuous ring around a periphery of said disk, and said liner is molded onto a radially inwardly facing surface of said ring.  
   
   
       10 . A two-piece plastic closure that comprises: 
 a plastic closure shell including a base wall with a central opening and a skirt with internal means for securing the closure to a container neck finish, and    a plastic disk loosely retained within said shell parallel to but separate from said base wall, said disk including an axially extending bead composed of a plurality of angularly spaced bead segments around a peripheral portion of said disk to space said disk from said base wall of said shell, a plurality of angularly spaced fingers extending from said disk through said central opening of said base wall concentrically with said bead and loosely retaining said disk within said shell, and a resilient sealing liner molded in situ on an underside of said disk in a two-material molding operation for sealing engagement with a container neck finish.    
   
   
       11 . The closure set forth in  claim 10  wherein each of said fingers is received by snap fit within said central opening.  
   
   
       12 . The closure set forth in  claim 10  wherein said disk has an axially extending circumferentially continuous ring around a periphery of said disk, and said liner is molded onto a radially inwardly facing surface of said ring.  
   
   
       13 . A plastic closure that comprises: 
 a plastic closure shell including a base wall with a central opening and a skirt for securing the closure to a container neck finish, and    a plastic disk retained within said shell parallel to but separate from said base wall, said disk including a plurality of axially extending spacer elements around said disk to engage an undersurface of said base wall and space said disk from said base wall of said shell, and angular gaps between said spacer elements to permit flow of fluid through said central opening, between said base wall and said disk and through said gaps, and a resilient sealing liner molded in situ on an underside of said disk in a two-material molding operation for sealing engagement with a container neck finish.    
   
   
       14 . The closure set forth in  claim 13  wherein said spacer elements comprise a plurality of angularly spaced circumferentially aligned bead segments around a peripheral portion of said disk.  
   
   
       15 . The closure set forth in  claim 13  wherein said disk is free to rotate with respect to said shell.  
   
   
       16 . The closure set forth in  claim 13  wherein said disk has an axially extending circumferentially continuous ring around a periphery of said disk, and said liner is molded in situ onto a radially inwardly facing surface of said ring.  
   
   
       17 . A two-piece plastic closure that comprises: 
 a plastic closure shell including a base wall with a central opening and a skirt for securing the closure to a container neck finish, and    a plastic disk loosely retained within said shell parallel to but separate from said base wall, said disk including an axially extending bead composed of a plurality of angularly spaced bead segments around a peripheral portion of said disk to space said disk from said base wall of said shell, and a resilient sealing liner molded in situ on an underside of said disk in a two-material molding operation for sealing engagement with a container neck finish.    
   
   
       18 . The closure set forth in  claim 17  wherein said disk has an axially extending circumferentially continuous ring around a periphery of said disk, and said liner is molded in situ onto a radially inwardly facing surface of said ring.  
   
   
       19 . A closure and container package that includes: 
 a container having a neck finish with at least one external thread segment, and    a two-piece plastic closure that comprises:    a closure shell including a base wall with a central opening and a skirt with at least one internal thread engaged with said external thread on said container finish,    a disk within said shell, said disk including a plurality of angularly spaced axially extending spacer elements around said disk in abutting engagement with said base wall spacing said disk from said base wall, angular gaps between said spacer channels to permit flow of fluid through said central opening, between said base wall and said disk, through said gaps and around said finish, and a resilient sealing liner on an underside of said disk in sealing engagement with said finish around a periphery of said disk, said liner being molded in situ in a two-material molding operation.    
   
   
       20 . The package set forth in  claim 19  wherein said spacer elements comprise a plurality of angularly spaced circumferentially aligned bead segments around a peripheral portion of said disk.  
   
   
       21 . The package set forth in  claim 19  wherein said disk is free to rotate with respect to said shell as said closure is secured to and removed from said container.  
   
   
       22 . The package set forth in  claim 19  wherein said disk has an axially extending circumferentially continuous ring around a periphery of said disk, and said liner is molded in situ onto a radially inwardly facing surface of said ring.