Abstract: A plastics pipe having a stabilised inner layer, wherein the inner layer comprises an extruded thermoplastic polymer comprising at least one polar stabilizer, wherein: (i) the thermoplastic polymer is provided with pendant polar functional groups, and/or (ii) the thermoplastic polymer comprises an effective amount of at least one filler provided with pendant polar functional groups, and/or (iii) the thermoplastic polymer comprises a blend of a non-polar thermoplastic polymer and a thermoplastic polymer provided with pendant polar functional groups.

Abstract: A pipe has an innermost layer, outside of which there is an inner electrode layer, outside of which there is an insulating layer, outside of which there is an outer electrode layer. The innermost layer is made of plastic by continuous extrusion and the insulating layer is made of foamed plastic.

Abstract: The invention relates to a branch piece for a pipework, comprising a body (1) including at least one branch fitting (2). A connecting piece (3) is arrangeable in the branch fitting (2). The branch piece includes a locking means made up of one or more parts for locking the connecting piece (3) in place.

Abstract: The heating and/or sanitation pipe comprises an inner pipe (12) made of a plastic material and a metal corrugated pipe (14) surrounding the inner pipe (12) at a radial distance {circle around (R)}). Further, the heating and/or sanitation pipe is provided with a compressible and/or expanded material (16) between the inner pipe (12) and the corrugated pipe (14) for fixing the inner pipe (12) inside the corrugated pipe (14). The compressible and/or expanded material (16) is adapted to be detached from the inner pipe for the purpose of exposing a connecting end of the inner pipe (12). Further, the heating and/or sanitation pipe comprises an insulation layer (18) surrounding the metal corrugated pipe (14) and an outer covering (20) around the insulation layer (18).

Abstract: A multilayer pipe which comprises at least an inner layer and an outer layer. The inner layer is made of extrudable plastic, such as polyethylene PE, cross-linked polyethylene PEX or polypropylene PP. The outer layer forms a fire-protecting layer and the matrix plastic of the outer layer is also made of extrudable plastic. A foaming agent, which does not react during the manufacture of the pipe, is mixed with the matrix. Further, the outer layer contains at least one additive in such a manner that the outer layer has a pipe-reinforcing component and a fire-retardant component. Most preferably, at least the outer layer is extruded by an extruder having a screw length ratio of less than 10 to its biggest diameter.

Abstract: Tapping fitting (1) suitable for application to a plastic pipe (P), comprising: a housing (5) including a hollow main section (6), the housing being attachable to a pipe (P); a cutter assembly (13) mountable within the hollow main section (6) and axially moveable therein into a cutting position wherein the cutting blade (14) engages the surface of a pipe (P) to which the fitting is attached; and a direct seal (23) between the housing (5) and the cutter assembly (13), wherein, in use, the seal (23) is maintained between the housing (5) and the cutter assembly (13) regardless of the axial position of the cutter assembly (13) within the housing (5).

Abstract: A method and an apparatus for making a pipe, and a pipe, wherein the pipe is made from a plastic feedstock pipe by expanding it against a mould. In the first step, that portion of the plastic feedstock pipe (4) which is to have a greater diameter than the rest of the pipe is partly expanded. Only after this is the entire plastic feedstock pipe (4) expanded against the mould (1).

Abstract: A process for the production of multi-layer metal composite tubes (10), wherein a metal strip is shaped to form a tube (16) and butt-welded along its two longitudinal edges. A plastic inner layer (12) is applied by extrusion in firmly adhering manner to the inside (12) of the metal tube (16) and a plastic outer layer (14) is applied by extrusion in firmly adhering manner to the outside (26) of the metal tube (16).

Abstract: An apparatus for manufacturing an extruded plastic product, the apparatus including at least one rotor and at least one stator defining a clearance having a feed gap between them, the rotor and stator collectively including a groove for moving material to be extruded from a feed zone of the apparatus to a shear zone of the apparatus upon rotation of the rotor and a countergroove for facilitating the extrusion of the material, the groove and countergroove being disposed on opposite sides of the feed gap, the countergroove having a thread that is opposite in direction to a thread of the groove, the groove having a cross-section that is substantially unchanging, the countergroove being disposed substantially along an entire length of the shear zone, the groove, countergroove and clearance forming a processing cavity having a volume that is the volumes of grooves, countergrooves and the clearance, the processing cavity having a cross-sectional area that decreases continuously along at least a part of an axis of t

Abstract: A branched pipe (5) is manufactured by continuous extrusion in such a manner that a manifold (5a) of a branched pipe (5) is manufactured by extruding plastic material into the space defined by moving chill moulds (1, 2) and a mandrel (10) arranged therein with an extruder (4). The manifold (5a) is provided with branch pipes (5b) simultaneously with the extrusion thereof.

Abstract: The invention relates to a method and apparatus for using recycled plastic material, and to a plastic product produced by an extruder. In the invention, crosslinked polyethylene is ground to powder form and mixed with e.g. polyethylene so that the proportion of the crosslinked polyethylene in the mixture is less than 30%. The mixture is supplied through an extruder (2) for making an extruded plastic product. In this way, crosslinked polyethylene can be recycled in a cost-effective and simple manner, while producing a plastic product that contains recycled crosslinked polyethylene.

Abstract: A plastic pipe provided with a socket and a method of providing a plastic pipe with a socket, whereby the socket comprises at least two layers. The orientation of at least one socket layer is different from the orientation of another layer and the orientation of at least one layer is different from the orientation of a body portion of the plastic pipe. The socket is made for instance from a plastic pipe comprising at least two layers. The orientation temperatures of at least two different layers are different. The plastic pipe is heated to a temperature at which the material of at least one layer is oriented during expansion and the material of at least one layer is substantially not oriented during expansion. The end of the plastic pipe is expanded at said temperature so as to provide it with a socket.

Abstract: The invention relates to a method and an arrangement for cooling an extruded hollow product. According to the invention, the extruder (1) is provided with means for sucking air through the pipe (2). The air to be sucked is thus in contact with the inner surface of the pipe (2), cooling the pipe from the inside. Therefore the cooling of the pipe (2) can be realized in an efficient and simple manner. By arranging the sucking to occur from the middle of the conical extruder (1), no weld line will be formed in the extruded product, and the extruder (1) can be cooled effectively from the inside. According to the invention, the heat contained by the air that has been sucked through the pipe (2) can also be utilized.

Abstract: An extruded multilayer plastic pipe is provided. The pipe comprises an inner layer, an outer layer and an intermediate layer. Each of the inner and outer layers is comprised of a thermoplastic material. The intermediate layer consists essentially of a lower density material than said inner and outer layers, and the intermediate layer is situated between and abuts both the inner layer and the outer layer. At least one of the inner, outer and intermediate layers consists of reinforced solid or foamed reprocessed plastic.

Abstract: The invention relates to a method and an apparatus for manufacturing an extruded plastic product, the apparatus comprising at least one rotor (1) and at least one stator (2, 3) 4 with a feed gap (4) provided between them, a groove (7) being situated on the other side of the feed gap (4), the groove pressing the material to be extruded out of the apparatus when the rotor (1) is rotated. The cross section of the groove (7) remains substantially unchanged. At the opposite side of the feed gap (4) there is positioned a countergroove (8) in such a way that a processing cavity consisting of the grooves (7), the countergrooves (8) and the clearance between 6 them decreases at least partially continuously along 5 the axis of the extruder. The deformation energy of the material can thus be kept as small as possible due to the unchanging cross section of the groove (7), and the material stays in the groove (7) due to the placement of the flights (7a, 8a).

Abstract: An extrusion apparatus and method, and a tubular product and a pipe made of several different materials.

Abstract: A pipe connector (1) for a multi-layer composite pipe, the pipe comprising at least one reinforcing layer (13, 14), or layer of high axial strength, at least one inner thermoplastic layer (9, 10) and at least one outer protective layer (15, 16), the connector comprising: (i) a hollow, tubular enclosure (2) adapted to receive the pipe; (ii) fusion means adapted to make a fusion connection with the inner thermoplastic layer of the pipe; (iii) mechanical gripping means (7) adapted to grip the reinforcing layer, or layer of high axial strength of the pipe; and (iv) optionally sealing means (6) adapted to form an environmental seal with the outer protective layer of the pipe, the electrofusion means (8), mechanical gripping means and optional sealing means being disposed within the enclosure and the enclosure being adapted, in use, to apply a constraining force to the mechanical gripping means and the sealing means.

Abstract: A branched pipe (5) is manufactured by continuous extrusion in such a manner that a manifold (5a) of a branched pipe (5) is manufactured by extruding plastic material into the space defined by moving chill molds (1, 2) and a mandrel (10) arranged therein with an extruder (4). The manifold (5a) is provided with branch pipes (5b) simultaneously with the extrusion thereof.

Abstract: A branched pipe (5) is manufactured by continuous extrusion in such a manner that a manifold (5a) of a branched pipe (5) is manufactured by extruding plastic material into the space defined by moving chill moulds (1, 2) and a mandrel (10) arranged therein with an extruder (4). The manifold (5a) is provided with branch pipes (5b) simultaneously with the extrusion thereof.

Abstract: A method for manufacturing an extrudable product including the steps of (a) providing an apparatus including an extruder having at least one rotor with first grooves, at least one stator with second grooves and a clearance between the rotor and the stator, the first grooves, second grooves and clearance forming a processing cavity having a volume that is equal to the volumes of the first grooves, the second grooves and the clearance, the processing cavity having a cross-sectional area that decreases continuously along at least a part of an axis of the extruder, the extruder further having a supply for feeding a material to be extruded into the processing cavity; b) feeding the material to be extruded in a powder, pellet or granuate form into the processing cavity through the supply and causing rotation of the rotor relative to the stator such that the material is forced to proceed along an x-axis in a shear zone of the extruder where the material is subjected to a shear which causes a fictional heat that melt