Molded plastic container with reduced neck ovality

Abstract

A plastic container has a main body portion, a neck portion and a molded feature such as an anti-rotation lug adjacent to the neck portion. The molded feature has a volume that is less than a volume that would be defined by the maximum external dimensions of the feature. This reduces the shrinkage differential between the molded feature and the neck portion, which could otherwise cause sealing problems with a closure as a result of deformation of the neck portion. A method of correcting a sealing problem in a plastic container by reducing the volume of the molded feature is also disclosed.

What is claimed is: 
     
         1 . A method of correcting a sealing problem in a plastic container having a main body portion defining an interior space, a neck portion defining an opening and having a sealing surface that is designed to seal with respect to a closure and a molded feature that is integral with the neck portion, comprising steps of:
 identifying a sealing problem that is created by differential shrinkage of the molded feature with respect to another portion of the container; and   reducing the volume of the molded feature with respect to a volume that is defined by the maximum external dimensions of the molded feature.   
     
     
         2 . A method of correcting a sealing problem according to  claim 1 , wherein the step of reducing the volume of the molded feature is performed by conducting a mold tooling change. 
     
     
         3 . A method of correcting a sealing problem according to  claim 1 , wherein the step of reducing the volume of the molded feature is performed by revising the shape of the molded feature to include a cavity. 
     
     
         4 . A method of correcting a sealing problem according to  claim 3 , wherein the cavity has an opening that faces in a direction that is substantially opposite from the neck portion. 
     
     
         5 . A method of correcting a sealing problem according to  claim 1 , wherein the molded feature comprises an anti-rotation lug.