Method of supporting plastic containers during product filling and packaging when exposed to elevated temperatures and internal pressure variations

Abstract

A method of supporting a plastic container exposed to elevated temperatures during product filling and packaging to eliminate heat and internal pressure induced distortion, internal vacuum distortion, or structural failure. Plastic containers usually have a body with exterior configuration and a sealable open mouth. The invention provides a method of hot filling, pasteurising and retort processing of conventional containers during product filling where at least a portion of the container is confined in a support casing having an interior cavity mating the exterior configuration of the container body portion. The product is then introduced into the container, and the container mouth is sealed. A positive pressure is induced within the sealed container while the container is exposed to a product processing temperature. An unsupported PET container exposed to high heat and internal pressure variations would distort or fail. However, the external mating support casing together with positive internal pressure restrains the PET container during this period of high stress and low resistance thereby preventing distortion or failure. Afterwards, by cooling the container to a casing release temperature below the product processing temperature and then releasing the container from the casing, eliminates container distortion problems.