Abstract: An adhesive valve that includes a flexible label having an upper surface and a lower surface provided with adhesive is disclosed. The value includes a flexible membrane which is applied to the lower surface of the flexible label and has a substantially non-adhesive lower surface and can be adhesively joined to a further surface so that the flexible membrane is arranged between the flexible label and further surface. The flexible label has an incision that connects the two surfaces of the flexible label at the flexible membrane. An incision connects the two surfaces of the flexible membrane and is covered by the flexible label. The incision in the flexible membrane forms a tongue-shaped portion. The invention also relates to a sheet a laminated material and a food container containing the adhesive valve, as well as a process for manufacturing the laminated sheet or material.

Abstract: Self-adhesive label valves are disclosed having release chimneys in correspondence of a plurality of intersection cuts in a membrane-island of film (tape) carrier (C) with cuts made in the overlying self-adhesive label made of polymeric film (E) with an adhesive layer. All are inscribed within (i.e. inside) the perimeter of the membrane-island, and are destined to overlie so as to occlude pre-formed release openings in the packaging film of heatable food, and ensure in an outstandingly reliable manner a gradual release of vapors while heating, without causing an undesirable collapse of the packaging film.

Abstract: Self-adhesive label valves are disclosed having release chimneys in correspondence of a plurality of intersection cuts in a membrane-island of film (tape) carrier (C) with cuts made in the overlying self-adhesive label made of polymeric film (E) with an adhesive layer. All are inscribed within (i.e. inside) the perimeter of the membrane-island, and are destined to overlie so as to occlude pre-formed release openings in the packaging film of heatable food, and ensure in an outstandingly reliable manner a gradual release of vapors while heating, without causing an undesirable collapse of the packaging film.