US Patent 9764863 Heat sealing thru food contaminants

A container is provided with a flange defining a container opening that may help expunge food product as the film and seal head comes down on the container flange. The flange of the container opening has a predetermined angle. The container flange with its sealing surface generally deflects or angularly pivots when sealed with the film during the sealing process. The container flange and film may push product contamination from the sealing surfaces inwardly into the container. The flange may be continuous about the periphery of the container opening.