Sealing surface for plastic closure with radial seal

Abstract

A novel method for sealing a plastic closure to a container flange using an elastomeric gasket. A plurality of annular sealing bands are positioned on the diametric sealing surface of the closure on which the gasket rests. As the closure is threaded into the container, the annular sealing bands become embedded within the gasket to improve the seal and overcome the negative sealing effects of the parting line flash present on the closure portion of the seal gland as a result of the manufacturing process.

What is claimed is:  
     
         1 . A closure adapted to be seated within an opening of a container for selective access to materials within the container, said closure comprising: 
 a cap portion,    an annular side wall portion beneath the cap portion, the annular side wall portion comprising a top neck section, a threaded section beneath the top neck section, and a bottom section beneath the threaded section, and    an annular sealing band situated around the top neck section of the annular side wall portion.    
     
     
         2 . The closure as in  claim 1 , further comprising a plurality of annular sealing bands situated around the top neck section of the annular side wall portion.  
     
     
         3 . A plastic closure for threaded engagement with a container, the closure employing a gasket to provide a seal between the closure and the container, the closure comprising: 
 a cap portion,    an annular side wall portion beneath the cap portion and having a smaller diameter than the cap portion, the annular side wall portion comprising a top neck section, a threaded section beneath the top neck section, and a bottom section beneath the threaded section, and    a plurality of annular sealing bands situated around the top neck section of the annular side wall portion, whereby as the closure is threaded within the container, the sealing bands releasably engage the gasket, thereby improving the effectiveness of the gasket.    
     
     
         4 . The closure as in  claim 3 , wherein the annular sealing bands have a sawtooth shape pointing upwards and outwards, for better engagement with the gasket.  
     
     
         5 . The closure as in  claim 4 , wherein the annular sealing bands have a top surface and an angled surface, the angled surface being angled upwards approximately 50° from horizontal.  
     
     
         6 . The closure as in  claim 5 , wherein the top surface of the annular bands is displaced downwards approximately 10° degrees from horizontal.  
     
     
         7 . The closure as in  claim 3 , wherein the annular sealing bands are integrally molded within the closure.  
     
     
         8 . The closure as in  claim 7 , wherein the bottom section of the annular side wall portion is tapered for ready insertion with the container.