The production of a biaxially oriented tube from thermoplastic material, wherein a tube in preform condition is extruded from thermoplastic material using an extruder having an extruder die head with an inner die member that forms a lumen in the tube in preform condition. The tube in preform condition is subjected to a temperature conditioning. Use is made of a expansion device comprising a non-deformable expansion part having a gradually increasing diameter to a maximum diameter, which expansion part is contacted by the tube and exerts an expanding force so as to bring about expansion of the tempered tube in circumferential direction. The method comprises drawing the tempered tube over the expansion device using a drawing device, in such a manner that said tube is transformed from a tube in preform condition into a biaxially oriented tube with thermoplastic material which is oriented in axial direction and in circumferential direction of the tube.

A pressure chamber is provided for a blown film extrusion apparatus having (i) a die head for extruding a tubular polymer bubble, and (ii) a cooling assembly down-stream of the die head for receiving the bubble and applying a cooling fluid to the bubble. The pressure chamber includes an upstream end wall sealed around the die head outlet, and extending outward from the seal; a side wall movable between a closed position for controlling air flow from a chamber volume surrounding the bubble to the atmosphere, and an open position for permitting air flow from the chamber volume to the atmosphere. The upstream end wall has an inlet for receiving air from an air supply, and an outlet in fluid communication with the inlet and configured to direct the air into the chamber volume to pressurize the chamber volume when the side wall is in the closed position.

The invention describes a method for the production and further processing of a film tube (6), in which method a plastic melt is transferred into a cylindrical melt by means of an extrusion die (4), the melt flow is drawn out through an annular gap (5) associated with the extrusion die (4) in order to form the film tube (6), and at least one temperature-controlled volume flow comprising at least one fluid is conducted by means of a temperature control device (8) onto the outer periphery of the film tube (6), wherein the temperature control device (8) is divided into peripheral segments, wherein a volume flow of different magnitude and/or different temperature is produced by means of each peripheral segment such that the temperature control of the film tube (6) differs over the periphery of the film tube, and wherein the film tube (6) is flattened by means of a flattening device (9), the flattening device (9) being rotated in relation to the extrusion die (4). A first volume flow in at least one peripheral segment of the temperature control device (8) differs from the volume flow of other peripheral segments so that at least one thick point (13) is produced on the film tube, wherein the first volume flow is produced by means of adjacent peripheral segments in succession, wherein the first volume flow is produced by means of the corresponding at least one peripheral segment in such a way that the first volume flow is adapted to the rotation of the flattening device (9) such that the at least one thick point (13) assumes substantially the same position in relation to the flattening device (9).

A polyetheretherketone pipe of length greater than 250 meters and a residual stress of less than 5 MPa may be made using a calibrator device 2 which includes a cone shaped opening 6 arranged to receive a molten extruded pipe shaped polymer. Attached to the front member 4 is a vacuum plate 14a and successive vacuum plates 14b-14h are attached to one another to define an array of vacuum plates, the vacuum plates being arranged to allow a vacuum to be applied to a pipe precursor passing through opening 16. The vacuum plates 14 also include temperature control means for heating or cooling the plates and therefore heating or cooling a pipe precursor passing through the openings. With a vacuum applied to opening 6, 16 and heating/cooling the plates, an extruded hot plastics pipe is inserted into calibrator 2 via opening 6 and conveyed through opening 16 in plates 14, whereupon it is urged by the vacuum against the cylindrical surface defined by plates 14 to maintain its shape and the temperature of each plate is controlled to control the rate of cooling of the pipe precursor passing through. The pipe may be cooled at a relatively slow rate so that a pipe made from a relatively fast crystallising polymer crystalises and the crystallinity of the pipe along its extent and throughout its thickness is substantially constant.

A sizer for cooling an extrudate includes a core and a housing. The core includes an extrusion channel which accommodates the extrudate, a core cooling channel, and a core vacuum channel in fluid communication with said extrusion channel. The housing includes a housing cooling channel, a housing vacuum channel, a cooling intake, and a cooling exhaust. The housing cooling and vacuum channels having curved segments. The cooling intake and exhaust being in fluid communication with said housing cooling channel.

A fin block is provided for a calibrating device for calibrating an extruded profile, wherein the fin block includes a fin structure, which has a plurality of fins. The fins are spaced apart from one another by grooves and are arranged in longitudinal direction (L) of the fin block. The fin block has at least one channel for feeding a temperature-control fluid, wherein the at least one channel is formed in an integrated manner in the fin block. Furthermore, a method is provided for the production of the above-mentioned fin block, and a calibrating device which includes a plurality of the above-mentioned fin blocks. Furthermore, a system for the additive manufacture of the above-mentioned fin block, a corresponding computer program and a corresponding data set is provided.

A lamella block is provided for a calibrating device for calibrating an extruded profile, wherein the lamella block includes a lamella structure, which has a plurality of lamellae that are spaced apart from each other by grooves and arranged in the longitudinal direction of the lamella block. The lamella structure has a variably designed division in the longitudinal direction of the lamella block. Further provided is a method for manufacturing the aforementioned lamella block, as well as a calibrating device, which includes a plurality of the lamella blocks mentioned above. Also provided is a system for additively fabricating the lamella blocks mentioned above, a corresponding computer program and a corresponding dataset.

A lamella block for a calibration device for the calibration of an extruded profile, wherein the lamella block includes a lamella structure having a plurality of lamellae, which are spaced apart from one another by grooves and arranged in the longitudinal direction of the lamella block. At least some of the lamellae are provided with at least one lamella opening with a predefined variable geometry. The application also relates to a method for producing said lamella. block, as well as a calibration device comprising a plurality of said lamella blocks. The application further relates to a system for additively manufacturing said lamella block, a corresponding computer program and corresponding data set.

A fin block is provided for a calibrating device for the calibrating of an extruded profile. The fin block includes a fin structure, which has a plurality of fins which are spaced apart from one another by grooves and are arranged in longitudinal direction of the fin block, wherein the fins of the fin structure have a variable dimension in longitudinal direction of the fin block. Further, there is provided a method for the production of the above-mentioned fin block and a calibrating device, which includes a plurality of the above-mentioned fin blocks. Furthermore, there is provided a system for the additive manufacture of the above-mentioned fin block, a corresponding computer program and corresponding data set.

A blown film line and process for making blown film, including an annular extrusion or coextrusion die, a plurality of nip rollers at a location remote from the annular die, a blown film bubble extruding from the annular die and traveling toward the nip rollers along a traveling path, an air cooling apparatus in the vicinity of the annular die, and a water cooling apparatus located downstream from the air cooling apparatus along the traveling path. The water cooling apparatus includes a wet porous material in direct contact with the blown film bubble and surrounding an outer circumference of the blown film bubble. The wet porous material continuously wipes the blown film bubble with water as the blown film bubble moves along the traveling path.