Method for the formation of a clamped wave seal structure

Abstract

A method is disclosed wherein a lid is engaged to a container by the formation of interlocking waves of lid material and container meterial about the interior rim of the container. The interlocking waves are geometrically aligned relative to the interior of the container so as to maximize the burst strength of the container, and also to minimize the force required to peel the lid from the container. An unheated clamp head is used to clamp the lid structure immediately adjacent a heated seal head used to form the interlocking wave structure about the inside rim of the container. The unheated clamp head prevents any melted portions of the containter or lid from flowing to or towards the outside rim of the container. Interlocking waves of material are thereby prevented from forming about the exterior rim of the container. The prevented formation of interlocking waves about the outside rim of the container yields a clamped-wave seal structure having reduced peel initiation forces and reduced average peel forces, without affecting the resistance of the container/lid system to high burst pressures typically encountered under retort conditions.

Dependencies are inferred from the claim text.