Method of producing a film made of a thermoplastic material
AssigneeReifenhauser GmbH & Co. Maschinenfabrik
InventorsEike Wedell, Helmut Meyer
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Abstract
A method and a device for producing a film made of a thermoplastic material, wherein a plastic melt is blown up into a film bubble and is shaped into a desired film by a calibrating arrangement, and a downstream arranged flattening device. For providing as contactless as possible a guidance, calibration and flattening, film guidance elements are used with a laminar uniform air cushion between the film guidance element and the surface of the film bubble, without contact between the surface of the film bubble and the film guidance element.
Claims10
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 (4a) 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 (E3) 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).
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), the method comprising:
- passing the film bubble (4) through a calibrating device (2) in which the film bubble (4) is calibrated to a predetermined diameter;
- flattening the film bubble (4) into a film web (4a) in a flattening device (3);
- supplying an air flow to each of a plurality of individual film guidance elements (5) of at least one of the calibrating device (2) or the flattening device (3), wherein each of the plurality of film guidance elements (5) is spaced apart from an adjacent film guidance element (5) and has a microporous layer facing the film bubble (4);
- forming a laminar air cushion between the film bubble (4) and the film guidance elements (5) for a contactless guidance of the film bubble (4) by an air flow exiting in a laminar air flow (E3) form from the microporous layer of each of the film guidance elements (5);
- and
- guiding the film bubble (4) by the air flow.
Dependencies are inferred from the claim text.