Provide is a blown film forming apparatus including a die including a columnar inner peripheral member and a cylindrical outer peripheral member that surrounds the inner peripheral member, and extruding a resin from a lip formed between the inner peripheral member and the outer peripheral member, and a plurality of die lip drive mechanisms including a fluid pressure actuator as a drive source and adjusting a lip width by applying a radial load to the outer peripheral member, in which the outer peripheral member includes a plurality of load receiving portions to which a load is applied by the die lip drive mechanism, and a stiffness reducing portion that is provided between the plurality of load receiving portions.

Provide is a blown film forming apparatus including a die including a columnar inner peripheral member and a cylindrical outer peripheral member that surrounds the inner peripheral member, and extruding a resin from a lip formed between the inner peripheral member and the outer peripheral member, and a plurality of die lip drive mechanisms including a fluid pressure actuator as a drive source and adjusting a lip width by applying a radial load to the outer peripheral member, in which the outer peripheral member includes a plurality of load receiving portions to which a load is applied by the die lip drive mechanism, and a stiffness reducing portion that is provided between the plurality of load receiving portions.

The invention relates to a blown film system for producing a film tube made of plastics material, comprising: an annular nozzle, out of which a plastic melt having a closed cross-section can be brought; a take-up device, by means of which the plastic melt can be drawn up from the direction of the annular nozzle so as to form the film tube; an air-provision device, which is downstream of the annular nozzle when viewed in the transport direction of the film tube and by means of which an amount of air can be provided; and a calibration device, which is downstream of the annular nozzle when viewed in the transport direction of the film tube and surrounds the film tube and by means of which the outer circumference of the film tube can be delimited. At least one detector is contained that has a plurality of detection elements, by means of which electromagnetic radiation emitted or reflected at various points of the film tube can be detected, such that at least one planar region and/or contoured region of the film tube can be detected with regard to characteristic properties, wherein the detector comprises at least 32 detection elements.

The invention relates to a blown film system for producing a film tube made of plastics material, comprising: an annular nozzle, out of which a plastic melt having a closed cross-section can be brought; a take-up device, by means of which the plastic melt can be drawn up from the direction of the annular nozzle so as to form the film tube; an air-provision device, which is downstream of the annular nozzle when viewed in the transport direction of the film tube and by means of which an amount of air can be provided; and a calibration device, which is downstream of the annular nozzle when viewed in the transport direction of the film tube and surrounds the film tube and by means of which the outer circumference of the film tube can be delimited. At least one detector is contained that has a plurality of detection elements, by means of which electromagnetic radiation emitted or reflected at various points of the film tube can be detected, such that at least one planar region and/or contoured region of the film tube can be detected with regard to characteristic properties, wherein the detector comprises at least 32 detection elements.

The invention relates to an apparatus and to a method for film production and/or film processing, characterized by a device for determining the flatness and/or evenness of the film and for further processing and/or outputting the determined results.

The invention relates to an apparatus and to a method for film production and/or film processing, characterized by a device for determining the flatness and/or evenness of the film and for further processing and/or outputting the determined results.

A method of manufacturing a blown film (F) comprising extruding it through a die (D), flattening the film with a folding angle that varies, measuring a transverse profile of a characteristic property of the blown film, which property is summed over two juxtaposed portions of a wall of the flattened film, and estimating a polar profile on the basis of said transverse profile, the method further comprising determining polar positions of the periphery of the flattened blown film that correspond to a transverse position of the film, determining discretized angle values flanking each of the polar positions, and, on the basis of said discretized angle values, computing interpolation coefficients that associate the polar profile of the film with a discretized polar profile of the film, and, based on said interpolation coefficients, updating the estimation of the discretized polar profile of the film by applying a Kalman filter.

A method of manufacturing a blown film (F) comprising extruding it through a die (D), flattening the film with a folding angle that varies, measuring a transverse profile of a characteristic property of the blown film, which property is summed over two juxtaposed portions of a wall of the flattened film, and estimating a polar profile on the basis of said transverse profile, the method further comprising determining polar positions of the periphery of the flattened blown film that correspond to a transverse position of the film, determining discretized angle values flanking each of the polar positions, and, on the basis of said discretized angle values, computing interpolation coefficients that associate the polar profile of the film with a discretized polar profile of the film, and, based on said interpolation coefficients, updating the estimation of the discretized polar profile of the film by applying a Kalman filter.

The invention describes a blown foil system for producing a foil web with at least one extruder for providing a melt-like plastic, a blowing head with a circumferential die gap, with which the melt-like plastic can be transformed into a foil bubble emerging from the die gap, with at least one liquid cooling device for cooling the foil bubble, wherein a liquid can be supplied to the outer periphery and/or to the inner periphery of the foil bubble by means of the liquid cooling device, with a flat laying device by means of which the foil bubble can be formed into a double-layer foil web, wherein the two layers are in contact at least partially and in particular substantially over the full surface, and with at least one stretch unit for stretching the foil web in the longitudinal direction.

The invention describes a blown foil system for producing a foil web with at least one extruder for providing a melt-like plastic, a blowing head with a circumferential die gap, with which the melt-like plastic can be transformed into a foil bubble emerging from the die gap, with at least one liquid cooling device for cooling the foil bubble, wherein a liquid can be supplied to the outer periphery and/or to the inner periphery of the foil bubble by means of the liquid cooling device, with a flat laying device by means of which the foil bubble can be formed into a double-layer foil web, wherein the two layers are in contact at least partially and in particular substantially over the full surface, and with at least one stretch unit for stretching the foil web in the longitudinal direction.