Plastic barrier closure and method of fabrication

Abstract

The present invention relates to a plastic barrier closure (or cap) for bottles and the like that has (1) a body having a top wall, a side wall, a securing means and a seal that has at least one concentric sealing member extending from the top wall, and (2) a barrier incorporated into the top wall. The barrier layer may be incorporated into the top wall by (1) depositing a melted mass of barrier polymer in the pre-molded cap body and then molding it into place by mechanical means or (2) forming a barrier layer from the barrier polymer and inserting it into a pre-molded cap body.

What is claimed is:  
     
         1 . A closure for a container having a cylindrical neck having an outer wall, an inner wall, and an opening rim with an inner edge and an outer edge comprising a body and a barrier layer wherein 
 a. the body comprises 
 (i) A disc-shaped top wall having an inside surface that is disposed so as to contact or nearly contact the rim of the container neck when engaged on the container neck,  
 (ii) A cylindrical side wall having an inside surface to contact or nearly contact the neck of the container when engaged on the neck attached to and extending essentially perpendicular from the top wall;  
 (iii) A means for securing the body with the container neck; and  
 (iv) A seal, wherein the seal comprises at least one sealing member that is attached to and extends from the inside surface of the top wall, is concentric with the cylindrical side, and is disposed so as to continuously contact the container neck when the body is engaged with the container neck; and  
   b the barrier layer is incorporated into the top wall of the body and is made from a barrier material selected to provide barrier against permeation of gas and absorption of flavor components of container contents when the body is secured to the neck of the container.    
     
     
         2 . The closure or  claim 1  wherein the seal comprises an inner sealing member and an outer sealing member, 
 a the outer sealing member that is attached to and extends from the inside surface of the top wall, is concentric with the cylindrical side, and is disposed so as to continuously contact the outside top edge of the container neck when the body is engaged with the container neck;  
 b the inner sealing member that is attached to and extends from the inside surface of the top wall of the body, is concentric with the outer sealing means, and is disposed so as to continuously contact the inner edge of the container neck when the body is engaged with the container neck.  
 
     
     
         3 . The closure of  claim 1  or  claim 2  wherein the securing means comprises internal threads in the cylindrical side wall that engage corresponding threads on the outside surface of the container neck.  
     
     
         4 . The closure of  claim 1  wherein the seal comprises an outer sealing member disposed to engage the outer edge or the outer wall of the neck of the container, and where the barrier layer is disposed to engage the top edge or inside edge of the neck of the container, when the closure is installed on the container.  
     
     
         5 . The closure of  claim 1  or  2  where the body is made from thermoplastic materials selected from the group consisting of polyolefins, nylon, polyvinyl chloride, polycarbonate, polystyrene, and polyester.  
     
     
         6 . The closure of  claim 5  wherein the polyolefins are selected from the group consisting of high-density polyethylene, low-density polyethylene, linear low-density polyethylene and polypropylene.  
     
     
         7 . The closure of  claim 1  where the barrier layer is incorporated into the top wall of the closure body using the in-shell molding process or the pick-and-place process.  
     
     
         8 . The closure of  claim 1  or  claim 2  where the barrier is made from materials selected from the group consisting of amorphous nylon, semicrystalline nylon, ethylene vinyl alcohol, polyvinylidene chloride, polyester, and polyacrylonitrile.  
     
     
         9 . The closure of  claim 5  where the body is made from high density polyethylene.  
     
     
         10 . The closure of  claim 8  where the barrier is made from amorphous nylon or 3GT polyester.  
     
     
         11 . The closure of  claim 1  where the container is a PET bottle.