Patent ID: 6564531
Filing Date: 2003-05-20
Classification: B29C,B29K,B65B,B65D

Abstract:
A method of permanently attaching a closure inside of an opening defined by a container made of a plastics material, comprising the steps of:a) providing a container, produced by a blow-molding process, from a preform having a suitable configuration and smaller than the closure, the opening being defined by a tubular wall portion of the container having internal stresses to provide a material memory whereby this portion has a propensity for contracting, toward the configuration and size of the preform, upon relief of internal stresses, of the material memory portion, resulting from the blow-molding process, by heating the material memory portion to a stress relieving temperature; b) providing a closure defining a closure periphery sized and shaped to fit within the tubular wall portion defining the opening; c) positioning the closure within the tubular wall portion defining the opening of the container with the closure periphery disposed proximate the tubular wall portion; and d) heating the tubular wall portion to the stress relieving temperature to relieve the internal stresses, of the material memory of the tubular wall portion resulting from the blow-molding process, sufficiently to cause the tubular wall portion defining the opening to contract, by virtue of relief of these internal stresses, toward the configuration and size of the preform and thereby to cause tubular wall portion defining the opening to engage and conform to the closure periphery to permanently secure and seal the closure within the opening without the need for mechanical force to supplement the action of the material memory.