In one example embodiment, disclosed is a biaxially oriented multilayer film, which may include a first tie layer and a second tie layer, wherein each has an inside surface and an outside surface. The film's core layer may consist of: (i) at least 50 wt. % high-crystalline polypropylene; (ii) both cyclic olefin copolymer and polypropylene homopolymer, or, polypropylene heterophasic copolymer; (iii) and, optionally, additives, wherein the core layer is between the inside surface of the first tie layer and the inside surface of the second tie layer. The film may also include a first skin layer on the outside surface of the first tie layer and a second skin layer on the outside surface of the second tie layer, wherein shrinkage is less than 3.5% in a transverse direction for the biaxially oriented multilayer film after subjecting the biaxially oriented multilayer film to 135° C. for 7 min at 1 atm.

A lamella block is provided for a calibrating device for calibrating an extruded profile. 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 two lamella sets, wherein the lamellae of the first lamella set are arranged offset in relation to the lamellae of the second lamella set in the longitudinal direction of the lamella block. Further provided is a method for manufacturing the lamella block mentioned above as well as a calibrating device, which includes a plurality of the lamella blocks mentioned above. Also provided is a system for additively manufacturing the lamella block mentioned above, a corresponding computer program and a corresponding dataset.

An air ring has a main body including a plenum through which pressurized air enters the air ring, the main body including a generally circular interior that is unobstructed vertically above the main body. A generally circular forming-cone assembly is received in the generally circular interior of the main body, and includes at least one annular lip defining a passage through which pressurized air from the plenum exits the air ring for impingement upon the polymer tube. A plurality of fasteners secure the forming-cone assembly in the interior of the main body, the fasteners and forming-cone assembly being unobstructed vertically above the air ring, wherein the fasteners are accessible from vertically above the air ring and the forming-cone assembly is removable from the main body by vertical lifting without removal of other components from the air ring.

A method for forming a multilayer plastic sheet material is disclosed, where a first polymer mass is melted under pressure and is passed through an extruder head at a specified discharge rate in the form of a plastic strand in sheet form that is provided with one or more layers so that a multilayer plastic strand is formed. This is passed to two or more rolls of a finishing stand that processes the multilayer plastic strand into a sheet. After the plastic strand in sheet form leaves the extruder head, it is first passed between a top roll and a bottom roll of a roughing stand. The speed of the rolls of the finishing stand and the rolls of the roughing stand is synchronized with the discharge rate of the plastic strand in sheet form from the extruder head, so that the plastic strand is processed without stress.

Mold blocks of a pipe molding corrugator are provided with enhanced cooling capability due to the provision of cooling fins on the side portions of each mold block. Air can be forced between the fins and some exhaustion of the air can occur at the base of the fins adjacent the mold block cavity. With this arrangement, enhanced cooling of mold blocks is possible.

A lamella block is provided for a calibrating device for calibrating an extruded profile. 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 two lamella sets, wherein the lamellae of the first lamella set are arranged offset in relation to the lamellae of the second lamella set in the longitudinal direction of the lamella block. Further provided is a method for manufacturing the lamella block mentioned above as well as a calibrating device, which includes a plurality of the lamella blocks mentioned above. Also provided is a system for additively manufacturing the lamella block mentioned above, a corresponding computer program and a corresponding dataset.

A method cuts an extruded pipe to length using a separating device. The separating device includes a separator rotating about an extrusion axis of the extruded pipe, the separator being rotatably mounted in the separating device, and cutting tools being arranged on the separator. The cutting tools are configured to carry out the separation. The method includes transferring energy to move the cutting tools. The energy is transferred from a stationary outer region of the separating device to a movable inner region of the separating device. The energy is transferred continuously or cyclically and the transferred energy is buffered in an energy storage device. The energy is transferred inductively or capacitively. A discharge time of the energy storage device is between 2% and 25% of a total separation cycle.

A method cuts an extruded pipe to length using a separating device. The separating device includes a separator rotating about an extrusion axis of the extruded pipe, the separator being rotatably mounted in the separating device, and cutting tools being arranged on the separator. The cutting tools are configured to carry out the separation. The method includes transferring energy to move the cutting tools. The energy is transferred from a stationary outer region of the separating device to a movable inner region of the separating device. The energy is transferred continuously or cyclically and the transferred energy is buffered in an energy storage device. The energy is transferred inductively or capacitively. A discharge time of the energy storage device is between 2% and 25% of a total separation cycle.

Mold blocks of a pipe molding corrugator are provided with enhanced cooling capability due to the provision of cooling fins on the side portions of each mold block. Air can be forced between the fins and some exhaustion of the air can occur at the base of the fins adjacent the mold block cavity. With this arrangement, enhanced cooling of mold blocks is possible.

A method for producing a biaxially oriented tube from thermoplastic material, wherein a tube in preform condition is extruded from thermoplastic material and is subjected to a temperature conditioning. Use is made of an expansion device and of a drawing device which is arranged downstream of the expansion device. The expansion device includes a non-deformable expansion part and a run-on part located upstream of the expansion part and having an upstream sealing member. The expansion device further includes a first gas discharge duct having one or more first inlet ports in the exterior surface of the expansion device, a first inlet port being open or closed or partly closed dependent on whether or not the first inlet port is covered and closed, or partly closed, by the tube.