Self-adhesive label valve

Self-adhesive label-valve (EV), alignedly applicable on the outer surface of a flexible packaging film of heatable food for sealing one or more openings (S) in the film for discharging vapors under pressure during the heating, defined by punching a laminated multilayer of at least a tape carrier (C), from which the label-valves may be taken individually, of a polymer suitable for packaging foods, having an anti-adherent coupling surface, and of a polymeric tape (E) with a pressure activated adhesive layer on the coupling surface, said label-valve comprising an island-membrane having a size adapted to overlie and occlude said opening/openings (S) through the film of the package, the perimeter of which is defined by the punching impression of the sole tape carrier (C), and the definition perimeter of the self-adhesive label around the geometrical projection of the area of the underlying island-membrane is defined by the punching impression of the sole polymeric tape (E) with adhesive layer together with one or more cuts, wherein

• said cuts are inscribed in the perimeter of the geometrical projection of the area of said underlying island-membrane;
• and
• at least one or more cuts are defined by the punching impression of the sole tape or film carrier (C) inside the definition perimeter of the island-membrane and intersect the geometrical projection of said cut/cuts of the overlying tape or film (E) with adhesive layer.