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.

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 film (F1) including cavities and formed from a polymer in which a cavitating agent is dispersed, said method including a step of extruding the polymer through an extrusion die equipped with adjustment actuators for adjusting thickness of the extruded film, and a step of stretching (Str1) the film, as well as establishing a mapping function of the film on the basis of mass-per-unit-area profiles of the film before and after the stretching step, establishing a stretch profile of the film as stretched on the basis of said mapping function and of said transverse mass-per-unit-area profiles, and establishing a characteristic transverse profile that is characteristic of the film on the basis of said stretch profile and of a transverse profile of the concentration by mass of cavitating agent in the film as stretched that makes it possible to take into account the distribution of the cavities in the film; in which method said adjustment actuators are controlled as a function of said characteristic transverse profile.

A method for the production control of an extruded plastic product with the following steps: recording at a first measuring point a first actual temperature of a measuring area provided on the plastic product, recording a second actual temperature of the measuring area at a second measuring point which is arranged at a distance from the first measuring point in a direction of extrusion of the plastic product, determining a setpoint temperature of the measuring area at the second measuring point, and outputting information on whether the second actual temperature is inside or outside a prescribed tolerance range of the setpoint temperature.

A device for determining the temperature of a tubular strand conveyed out of an extrusion device includes at least one temperature sensor configured to measure a first temperature of an outside of the tubular strand at a first position of the tubular strand. An evaluation apparatus further included and configured to compare the first temperature with a second temperature of the outside of the tubular strand at a second position of the tubular strand and determine at least one of a temperature within the tubular strand or a temperature on the inside of the tubular strand at a position of the tubular strand based on the comparison of the first and second temperature.

A rubber member molding method for molding a rubber member having a belt shape by attaching rubber discharged from a die to a molding surface while relatively moving the die and the molding surface in a direction along the molding surface, the rubber member molding method includes setting, as an abutting position, a position where a first one of the die and the molding surface is moved in a direction of moving closer to a second one and abuts on the second one before start of molding, and setting, as a molding start position, a position where the first one is moved from the abutting position in a direction of moving away from the second one by a desired thickness of a rubber member at the start of molding.

Disclosed is an apparatus for the production of a blown tubular film (FT). The apparatus includes an independent device for the localized thickness adjustment at the strips adjacent to the folding edges resulting from the flattening of the tubular film (FT) by means of adjustment elements formed in angular sectors of limited extension symmetrically arranged 180° apart. The independent device for the localized thickness adjustment being a volumetric type device having a rotating ring that performs a rotating adjustment of the flow rate of a cooling air stream which takes into account the angular offset resulting from the operational parameters of the apparatus.

Extrusion techniques for reducing bow of an extrudate formed from a ceramic forming mixture. Velocities of an outer surface of the extrudate are measured at a plurality of peripherally spaced measurement locations. The velocities are compared to determine whether there is a velocity bias, and the comparison is used to selectively alter the flow of the ceramic forming mixture.