The carton and package provide a heat-releasable connection for a closure for a package which is to be heated for use wherein the heat sealed connection will become ineffective when subjected to boiling water conditions. In one form, the closure is a lid for a tray type container. In the second form the closure is a small closure for a small aperture in the lid wherein the size of the aperture is such that it will act as a one-way valve when the package is heated underneath the surface of the water to allow escape of steam or vapor under pressure and to prevent the ingress of water.
A packaging container having a pressure relief valve which is suitable for packaging products that are vulnerable to oxygen and products that give off gases. The packaging container has at least one rigid and flat wall, which is surrounded by an offstanding peripheral flange and on the outside surface of which the pressure relief valve is secured. The pressure relief valve has a flexible membrane, which is secured on the wall in opposed peripheral zones by means of two adhesive strips. With its middle zone, the membrane defines a path and covers an opening in the wall. The opening is located in an indentation by means of which a pressure-action surface of the membrane is provided. A film of oil may be added in the middle zone to assist in preventing entrance of air into the container.
An end unit intended for packaging products in an associated can or container wherein the product is of the type producing gases so as to normally increase the internal pressure within the can after the closing of the can. The end unit has a vent opening therethrough and is normally closed by a closure member which is held in contact with the container wall surrounding the vent opening by a strip of stretchable material having a memory. When pressure within the container exceeds a predetermined pressure, the closure will move out of the container sealing position under the restraint of the strip, and the container will be vented to the atmosphere.
A food storage and reheating receptacle (1) with a lid having heat openable apertures (4). Material of lid is such that cut outs on lid tend to bend or deflect from lid surface upon heating thereby causing ventilation of contents of receptacle.
An overpressure valve for a packaging container, which prevents air from the atmosphere from getting into the package and, in the case of gas-emitting material being packaged, reduces a resultant overpressure by venting gas. The overpressure includes a valve membrane stuck to a wall of the container on top of through holes. The membrane is secured to the wall with peripheral adhesive strips, leaving an adhesive-free zone above the through holes; the adhesive-free zone forms a valve member, and the congruent part of the wall forms a valve seat. The adhesive strips have a wedge shape, so that the transitional regions of the adhesive-free zone toward the adhesive strips, rest on the wall, and the raised peripheral regions form spacers for adjacent packages to permit operation of the overpressure valve while stacked one on the other.
Closure membrane for containers having an outer film and inner film with a joining layer and a sealing seam zone between these two films. At least one space free of a bonding layer is provided within the sealing seam zone between the outer film and the inner film and, within the limits of this non-bonded space, the outer film and the inner film each feature at least one opening, and a reservoir of material that softens under the influence of heat is provided in the non-bonded space between the outer film and the inner film. The openings in the inner film and the openings in the outer film are connected to enable the passage of a fluid such as a gas from the interior of the container to the surrounding atmosphere. On application of heat to the closure membrane e.g. during a sterilization process, the openings in the inner film and the outer film are closed off as a result of softening of the material that softens under the influence of heat.
