An improved lid for heat-sealing a container is proposed which comprises a substrate and an outer peel layer laminated to the substrate through two adhesive layers, one of which has a weaker adhesion strength than the other. The substrate has a base sheet and is formed with such a discontinuous cut outlining...http://www.google.es/patents/US4771937?utm_source=gb-gplus-sharePatente US4771937 - Lid for heat-sealing container
