A method for winding a foil onto a winding core in order to form a coil and for unwinding the foil from the winding core. The foil comprises a support material of an electrode foil and an electrode foil, which has at least one active material, or a separator foil which are used as components of a battery cell. The winding core has a perforated circumferential surface with at least one opening. A coil is also provided that has at least a winding core and a foil which is wound on the winding core.

A method and apparatus for the production of coreless paper rolls, including a winding phase on a central spindle of a paper web carried out by a main reel, until the formation of a wound paper roll, a phase of extraction from the wound roll of the spindle by application of a relative axial extraction force between the roll and the spindle, where the winding phase includes a first winding phase of a number of web revolutions on the central spindle performed at a first winding tension that is lower than the next winding tension.