Patent ID: 8292212

Claim:
A method for removing a coreless coil of a plastic film from a winding mandrel having an external surface, said mandrel comprising: an air distribution chamber axially extending between a back end and a fore end of the mandrel; wherein said air distribution chamber is connectable to a source of pressurized air and is provided with a plurality of air outlet holes to create an air cushion between the external surface of the mandrel and internal turns of the coreless coil; and wherein the coreless coil is removable by sliding it towards the fore end of the mandrel, said method comprising the steps of: sliding a tight piston inside the air distribution chamber of the mandrel; feeding pressurized air at the fore end of the air distribution chamber at the moment of removal of the coreless coil; and advancing the coreless coil pushing it along the mandrel and simultaneously magnetically dragging the tight piston along the air distribution chamber, allowing the outflow of the pressurized air from the holes of the mandrel at a front part of the air distribution chamber between the tight piston and the fore end of the mandrel.