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 process for producing moldings with condensing-up of a polyamide molding composition whose polyamide component contains, as a result of the method of preparation, at least 5 ppm of phosphorus in the form of an acidic compound by means of a compound having at least two carbonate units, wherein a) from 0.001 to 10% by weight, based on the polyamide, of a salt of a weak acid is added to the polyamide molding composition prior to compounding or during compounding, b) a mixture of the finished composition and the compound having at least two carbonate units is prepared, c) the mixture is, if appropriate, stored and/or transported and d) the mixture is subsequently processed to produce the molding, with the condensing-up occurring only in this step, effects a significant increase in the melt stiffness combined with moderate processing pressures, which considerably simplifies, in particular, the production of hollow bodies and hollow profiles having large diameters.

Abstract: A process for producing moldings with condensing-up of a polyamide molding composition by means of a compound having at least two carbonate units, wherein a) a polyamide molding composition is made available, b) a mixture of the polyamide molding composition and the compound having at least two carbonate units is prepared, c) the mixture is, if appropriate, stored and/or transported and d) the mixture is subsequently processed to produce the molding, with the condensing-up occurring only in this step, and the molding is a hollow body or hollow profile having an external diameter of at least 30 mm and a wall thickness of at least 1 mm, effects a significant increase in the melt stiffness combined with moderate processing presssures, which considerably simplifies the production of these moldings.

Abstract: In a method for the introduction of an inliner into a pipe or a pipeline, where the external diameter of the inliner is greater than the internal diameter of the pipe or of the pipeline, and where the action of an external force is used to reduce the cross section of the inliner prior to the introduction, the inliner is composed of a polyamide moulding composition which comprises at least 50% by weight of polyamide which is not PA11. The recovery behavior of said polyamides is similar to that of polyethylene usually used for this purpose.

Abstract: A polyamide molding composition which can be used for production of a printable or printed item contains a) at most 90 parts by weight of a polyamide obtained from a lactam or from an amino carboxylic acid having at least 10 carbon atoms; and b) from 10 to 100 parts by weight of PA1010, wherein a total of components a) and b) is 100 parts by weight.

Abstract: A process for producing hydrolysis-resistant mouldings with geometries having large dimensions by cumulative condensation of a polyamide moulding composition, is provided. The process includes mixing a polyamide moulding composition of a polyamide having at least 50% of amino end groups with 0.1 to 5% by weight, based on the polyamide moulding composition, of an oligo- or polycarbodiimide. The mixture is subsequently processed to give the moulding, wherein cumulative condensation is obtained during the processing of the moulding.

Abstract: In 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 has been selected from the group of polyolefin moulding composition, polyamide moulding composition and polyvinylidene fluoride moulding composition, and also b) 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, polyphenylene sulphide, polyarylene ether ketone/polyphenylene sulphide blend, polyphenyl sulphone and polyalkylene naphthalate, the exterior reinforcement has particularly efficient protection from corrosion due to aggressive constituents which diffuse outwards from the fluid conveyed. The pipe therefore has particular suitability for offshore applications in the production of oil or of gas.

Abstract: The invention relates to a flexible pipe having a multi-layered structure comprising unbonded layers, comprising an inner lining having the following layer arrangement: a) an innermost layer made of a fluoropolymer molding compound, b) an intermediate layer made of a molding compound on the basis of an olefinic polymer, which is selected from the group consisting of polyethylene, isotactic polypropylene, syndiotactic polypropylene and syndiotactic polystyrene, c) an outer layer made of a polyamide molding compound, wherein the layer made of a polyamide molding compound is particularly efficiently protected against hydrolysis. The pipe is thus particularly suited for offshore applications in oil or gas production.

Abstract: The invention relates to a flexible tube of multilayer construction having unbonded layers, wherein at least one layer is formed in that a tape made of a plastic molding compound is spirally wound about a further inner layer, wherein the upper and lower layers of the tape are simultaneously or subsequently welded to each other at overlapping regions.

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: 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: A polyamide molding composition which can be used for production of a printable or printed item contains a) at most 90 parts by weight of a polyamide obtained from a lactam or from an amino carboxylic acid having at least 10 carbon atoms; and b) from 10 to 100 parts by weight of PA1010, wherein a total of components a) and b) is 100 parts by weight.

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 moulding composition which comprises at least 50% by weight of the following constituents: a) from 0 to 99 parts by weight of polyamide, and b) from 1 to 100 parts by weight of polyamide elastomer, selected from the group of polyetheresteramide and polyetheramide, where the total of the parts by weight is 100 and where the moulding composition comprises from 0 to 9% by weight of plasticizer, is used for the production of a moulding for contact with a supercritical medium, and preferably for the production of an inner thermoplastics layer in a flexible pipe or rigid pipe, in which a supercritical medium is conveyed. Low or zero plasticizer content eliminates any significant occurrence of problems such as increased stiffness and longitudinal shrinkage.

Abstract: A polyamide molding composition which can be used for production of a printable or printed item contains a) at most 90 parts by weight of a polyamide obtained from a lactam or from an amino carboxylic acid having at least 10 carbon atoms; and b) from 10 to 100 parts by weight of PA1010, wherein a total of components a) and b) is 100 parts by weight.