A tube forming apparatus for forming polymeric tubing includes a housing between rear and discharge ends. The tube forming apparatus includes a core tube assembly with an exterior core tube and an inner core tube positioned partially therein and in an interior area of the housing. The tube forming apparatus includes a die that has an inner die-surface. A diverter tip is mounted in and extends from the inner core tube into the die forming a die opening between the die and the diverter tip. The tube forming apparatus includes a core tube adjustment system mounted proximate the rear end which includes an axial displacement device configured to axially position the core tube assembly for modulating wall thickness of the tube and/or an angular displacement device configured to modulate the inner core tube for modulating concentricity of the tube.

A sensing system for measurement of a multilayered blown polymeric film. A feedblock supplies polymeric material streams to an annular blown film die to form a plurality of layers of different polymeric materials. A sensing system is positioned adjacent to a film bubble extruded from the blown film die, wherein the blown film bubble includes annular layers of at least two different polymeric materials. The sensing system emits a signal toward selected circumferential positions around the film bubble and receives a plurality of reflected signals at each circumferential position. Each reflected signal in the plurality of reflected signals is generated at an interface between annular layers that includes a refractive index change detectable by the sensing system. A processor processes the reflected signals from the sensing system, and for each circumferential position determines a layer thickness profile for each polymeric material in the film.

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.

Provided is a measurement device (10) for detecting local thickenings in a film web (20), more particularly an extrusion and/or coextrusion film, having a first roll (14) for rolling on the film web (20) that can be moved along, a second roll (18) that can be supported indirectly above the film web (20) on the first roll (14) for rolling on the film web (20) that can be moved along, wherein the second roll (18) is resiliently guided in the thickness direction of the film web (20) that can be moved along, more particularly in the vertical direction, and at least one distance sensor (24) that is stationary with respect to the first roll (14) and/or to the film web (20) that can be moved along, for detecting a distance of the second roll (18). The second roll (18), which can be displaced from a local thickening of the film web (20) in the thickness direction of the film web (20), makes it possible to quickly and easily detect local thickenings in a film web (20).

Methods and systems of measurement for blown film lines are provided. The sensing system includes a terahertz (THz) sensor positioned adjacent to a film bubble extruded from a blown film die, and a sensor support configured to guide the THz sensor around the circumference of the film bubble to measure its film thickness.

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.

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.

It is provided that a method for producing a biaxially oriented polyester film that can be used for industrial and packaging applications. A method for producing a biaxially oriented polyester film, comprising: a step of feeding a polyester resin into an extruder, a step of extruding the molten polyester resin from an extruder to obtain a molten resin sheet at 250 to 310° C., a step of attaching the molten resin sheet closely to a cooling roll by an electrostatic application method to obtain an unstretched sheet, and a step of biaxially stretching the unstretched sheet, wherein the polyester resin fulfills the following (A) to (C): (A) the polyester resin comprises a polyethylene furandicarboxylate resin composed of a furandicarboxylic acid and ethylene glycol; (B) an intrinsic viscosity of the polyester resin is 0.50 dL/g or more; (C) a melt specific resistance value at 250° C. of the polyester resin is 3.0×10.sup.7 Ω.Math.cm or less.

A method for the active adjustment of the profile of a film produced with blown extrusion technology, a film obtained with such method and a reel resulting from the winding of the film.