Patent ID: 7604770

Claim:
A method for producing a film made of a thermoplastic material, wherein a melt of a plastic material exits from a blow head ( 1 ) supplied by at least one extruder while forming a film bubble ( 4 ) and then the film bubble ( 4 ) passes through a calibrating device ( 2 ) in which the film bubble ( 4 ) is calibrated to a predetermined diameter and then is flattened into a film web ( 4 a ) in a flattening device ( 3 ), wherein at least one of the calibrating device ( 2 ) and the flattening device ( 3 ) have a plurality of film guidance elements ( 5 ) each spaced apart from an adjacent film guidance element ( 5 ) and each guiding the film bubble ( 4 ) on an exterior, wherein the film guidance elements ( 5 ) are charged with an air flow exiting from a side of the film guidance elements ( 5 ) facing the film bubble ( 4 ) and forming an air cushion between the film bubble ( 4 ) and the film guidance elements ( 5 ) for a contactless guidance of the film bubble ( 4 ), the method comprising the air flow exiting in a laminar air flow (E 3 ) form from the surface of each of the film guidance elements ( 5 ) facing the film bubble ( 4 ) and forming a laminar air cushion for the film bubble ( 4 ).