Abstract: A flexible pipe of multilayer structure with unbonded layers, where the pipe has an interior lining which comprises the following layers: a) at least one layer of which the material is composed of a moulding composition based on a polymer selected from the group of: polyarylene ether ketone, polyphenyl sulphone, polyphenylene sulphide, polyarylene ether ketone/polyphenylene sulphide blend and semiaromatic polyamide, where from 5 to 100 mol % of the dicarboxylic acid content thereof derives from an aromatic dicarboxylic acid having from 8 to 22 carbon atoms, and which has a crystallite melting point Tm of at least 260° C.; b) at least one layer of which the material is composed of a fluoropolymer moulding composition can be operated at temperatures above 130° C. The pipe has particular suitability for offshore applications in the production of oil or of gas.

Abstract: A flexible pipe which can be heated efficiently, and may therefore be used for conveying oil in cold regions, is provided. The pipe comprises in order from inside to outside: an interior lining; a wound tape; and at least one reinforcement layer. The wound tape contains a first exterior layer of a plastics molding composition that is not electrically conductive; an intermediate layer of an electrically conductive plastics molding composition; and a second exterior layer of a plastics molding composition that is not electrically conductive. A volume resistivity to IEC 60093 of the intermediate layer is in the range from 10?3 to 1010 ?m, and the intermediate layer comprises at least two metallic conductors embedded into the plastic molding composition along an entire length of the tape in such a way that, the two conductors do not touch one another.

Abstract: Multilayer composites are obtained from a molding composition which contains the following components: a) 100 parts by weight of polyamide and b) from 0.005 to 10 parts by weight of a compound having at least two carbonate units by coextruding with a molding composition based on a high-melting-point polymer whose crystallite melting point Tm is at least 255° C. and/or whose glass transition temperature Tg is at least 180° C.

Abstract: A flexible pipe of multilayer structure which comprises the following layers, from the inside to the outside: an interior lining; an inner reinforcement layer; a layer of molded electrically conductive plastic; an outer reinforcement layer; and an exterior sheath. The electrically conductive plastic layer is in electrical contact with the two reinforcement layers, and the two reinforcement layers can be connected to a source of electrical current. It is thus possible to achieve efficient heating of the pipe, and it can therefore be used for conveying oil in cold regions.

Abstract: A process for producing a plastic rod, in particular round rods, suitable for machining is provided. The process includes extruding a plastic profile of a first plastic molding composition which forms the outermost layer of the plastic rod, and inserting a second plastic molding composition as a rod core into the profile within a calibrator downstream of the extruder. The first plastic molding composition contains at least 50% by weight of a semicrystalline thermoplastic and the first plastics moulding composition has the following properties: a) crystallite melting point Tm in accordance with ISO 11357 of at least 170° C., b) crystallization temperature Tk in accordance with ISO 11357 of at most 70 K below T. and c) enthalpy of fusion AH in accordance with ISO 11357 of at least 20 J/g.

Abstract: The invention relates to a downhole heat exchanger for extracting geothermal energy from a borehole, wherein the inner surface of the exchanger tube comprises the following roughness values: a) an arithmetic mean roughness Ra according to DIN EN ISO 4287 in the range of 1 to 15 ?m, b) an averaged roughness Rz according to DIN EN ISO 4287 in the range of 8 to 80 ?m, and c) a maximum roughness depth Rz1 max according to DIN EN ISO 4287 in the range of 10 to 500 ?m, comprising an improved precipitation film during operation, such that the entire surface of the exchanger tube is uniformly wetted.

Abstract: A pipe or hose composed of a polyamide moulding composition whose molecular weight has been increased by condensation, via addition of a compound having at least two carbonate units in a quantitative proportion of from 0.005 to 10% by weight, based on polyamide, where a) a starting polyamide moulding composition was provided, b) a mixture of the starting polyamide moulding composition and of the compound having at least two carbonate units was produced, c) the premix was, if desired, stored and/or transported, and d) the premix was then processed to give the moulding, this step being the first in which the increase of molecular weight by condensation occurred, the moulding being a pipe or hose whose external diameter is at least 25 mm is used as inliner for a pipeline.

Abstract: A metal conduit pipe, which is covered with an extruded layer made of polyamide moulding compound, is used to produce a duct laid in water, wherein in the course of laying the duct, the coating is exposed to a shearing pressure load and/or a bending load due to laying method selected.

Abstract: The invention relates to an extrusion system for producing cylindrical semi-finished plastic products. The extrusion system comprises an extruder (1) for making available a pressurized plastic melt, at least one extrusion die (7) arranged on the extruder (1) and allowing the melt to leave the extruder (1) as a substantially cylindrical plastic strand (8), a calibration unit (2) which is mounted downstream of the extrusion die (7) and through which the freshly extruded plastic strand (8) passes, said calibration unit cooling the plastic strand (8) and giving it an outer diameter (d), a brake device (3) mounted downstream of the calibration unit (2) and adapted to introduce a variable axial force (A) into the plastic strand (8), said axial force being opposite to the advance of the plastic strand, and a force transducer (9) measuring the axial force (A) introduced into the plastic strand (8) by the brake device (3).

Abstract: A moulding compound for joining two mouldings each made of a PA11 and/or PA12 moulding compound contains at least 50% by weight of a polyamide component so chosen that it is preparable from linear aliphatic diamines and dicarboxylic acids and/or lactams or ?-aminocarboxylic acids, there being 11 to 12 carbon atoms present per carboxamide group in the repeating units, and, furthermore, this polyamide component containing not more than 80% by weight of either one of the polyamides PA11 and PA12. With this compound a firm weld is obtained both to a PA11 moulding and to a PA12 moulding.

Abstract: A coolant line includes an outer layer including a polyamide molding composition and an inner layer including polypropylene and at least 0.02% by weight of a heat stabilizer. The coolant line has a high thermal aging resistance and bursting strength.

Abstract: A pipeline laid trenchlessly and/or without a sand bed is produced using a metallic conduit which is encased with an extruded layer of a polyamide moulding material. In this way, the durability of the outer shell required for trenchless laying techniques without a sand bed is ensured.

Abstract: A pipe or hose composed of a polyamide moulding composition whose molecular weight has been increased by condensation, via addition of a compound having at least two carbonate units in a quantitative proportion of from 0.005 to 10% by weight, based on polyamide, where a) a starting polyamide moulding composition was provided, b) a mixture of the starting polyamide moulding composition and of the compound having at least two carbonate units was produced, c) the premix was, if desired, stored and/or transported, and d) the premix was then processed to give the moulding, this step being the first in which the increase of molecular weight by condensation occurred, the moulding being a pipe or hose whose external diameter is at least 25 mm is used as inliner for a pipeline.

Abstract: The invention relates to plastics composite mouldings obtainable via welding in an alternating electromagnetic field, in which the weld is obtained with the aid of a plastics material which comprises nano-scale, magnetic oxidic particles, which are composed of aggregated primary particles, and where the primary particles are composed of magnetic metal oxide domains whose diameter is from 2 to 100 nm in a non-magnetic metal oxide matrix or non-magnetic metalloid oxide matrix.

Abstract: A process for the bonding of a plastics pipe to another plastics part by ultrasound welding using sound waves which act longitudinally with respect to the pipe axis, while the arrangement of the areas to be welded is substantially parallel to the pipe axis. The welding procedure is combined with the forced insertion of the other plastics part into the plastics pipe in such a way that there is at least some overlap between the exposure to sound and the forced insertion.

Abstract: A process for the bonding of a plastics pipe to another plastics part by ultrasound welding using sound waves which act longitudinally with respect to the pipe axis, while the arrangement of the areas to be welded is substantially parallel to the pipe axis. The welding procedure is combined with the forced insertion of the other plastics part into the plastics pipe in such a way that there is at least some overlap between the exposure to sound and the forced insertion.

Abstract: A method for connecting a plastic pipe to another plastic part, wherein an outer layer of the plastic pipe and an outer layer of the other plastic part are largely opaque to laser light, in which both the plastic pipe and the other plastic part are sheathed at the ends by an adaptor made of a plastic transmissive to laser light, and the adaptor is fastened by means of laser welding. In other embodiments, an adaptor of a material transmissive to laser light is molded together with another plastic part by a two-component injection-molding process, or the adaptor is molded and then overmolded to the other plastic part. This is followed by insertion of the pipe into the adaptor and fastening of the pipe to the adaptor by laser welding. The invention also relates to the composite parts produced according to this method.

Abstract: The present invention relates to a liquid or vapor conducting system containing an attachment cohesively bonded to a hollow article by way of a coextruded multilayer composite and a method for bonding single- or multilayer hollow plastic articles to attachments. Within the present invention the attachments include: attachment nipples, threaded necks, closure caps, and valves; and the bond is made with the aid of a semifinished or finished product produced from a coextrudate.

Abstract: A thermoforming process for forming a plastic pipe using a high-frequency field to introduce the required heat. The pipes thermoformed according to the invention are used, for example, in the motor vehicle sector.