IMPROVING CONFIGURATION OF CONTAINER AFTER STERILIZATION

摘要

Methods are provided for obtaining an acceptable configuration of a thermally processed plastics container packed with food; improvements in container configuration are attained by proper container design, by maintaining a proper headspace of gases in the container during thermal processing by establishing a vacuum in the container as it is sealed and/or by controlled reforming of the bottom wall of the container. Reforming is achieved by creating an excess external pressure on the container which is sufficient to cause the bottom wall but not any portion of the sidewall to move inwardly. Further improvements are attained by controlling the thermal history of the empty container, such as by pre-shrinking the container before it is filled with food and sealed.