Abstract: A method and plate structure for peelably sealing lidding stock to a sealing flange of a container. The plate structure has a face portion that is configured in cross section to contact the lidding stock and force the same against the flange surface without cutting the sealing layer of the stock and in a manner that indents the stock and flange, and retains sealing material in a sealing area to effect a good but peelable seal between the lidding stock and flange. The face portion includes an indentor made of a material of high thermal conductivity relative to the material of the remainder of the plate structure.

Abstract: An easily-openable container lid made from a laminate material which includes a thick outer thermoplastic layer, a thin intermediate gas barrier layer, preferably of metallic foil, and a heat-sealable inner coating or film layer. A score line extends only partially through the outermost layer of this container lid to define an openable section thereof. The lid is further provided with a pull tab severing laminate material along its score line without delaminating, said tab being affixed to the openable lid section with a hollow, integrally-formed rivet. A retortable container and laminate lid combination is also disclosed.

Abstract: A closure assembly is disclosed which includes a plastic sealing ring having an annular channel in it for receiving and sealing against the entrance mouth of a container, a metal foil liner spanning the sealing ring and a flexible plastic overcap which receives the sealing ring and foil liner therein. The foil liner has a heat seal coating on one or both faces for sealing to the sealing ring and, in some packages, to the plastic overcap. The three-piece closure assembly is positioned on the entrance mouth of a container and the foil liner is induction heated to soften the heat seal coating thereon to seal the liner to the sealing ring. Induction heating may also be employed to adhesively join the foil liner to the undersurface of the overcap and seal the sealing ring to a foil layer in the container body.