Method of manufacturing a lid for a container

摘要

Lid (2) for closing a cup (1) along a peripheral sealing edge (10), comprises at least one aluminum foil and an optionally multi-layered plastic co-extruded on the aluminum foil. A closed predetermined tearing line (3) is provided in the plastic layer. At least one layer of the plastic layer is made of polyethylene based plastic or polypropylene based plastic. The predetermined tearing line is introduced into the plastic layer preferably by a carbon dioxide laser. An independent claim is included for producing the lid, comprising passing the lid material present in the form of an endless band, with the plastic layers facing the laser and placed on a supporting surface, focusing the laser beam to a diameter of 150-350 mu m, preferably 210 mu m, where the beam is focused on a spot above the aluminum foil.