Abstract: A flexible conduit for coolant having a high bursting pressure above 8 bar at 100.degree. C. and high hydrolysis resistance comprising an outer layer of a material selected from the group consisting of homopolyamides, copolyamides and mixtures thereof with an excess of amino terminal groups, a non-swelling inner layer made of a material selected from the group consisting of non-halogenated copolyolefins, non-halogenated homopolyolefins and mixtures thereof and a middle layer compatible with the inner and outer layers made of a homopolyolefin or a copolyolefin with grafted functional groups, the layers being coextruded and corrugated during coextrusion.

Abstract: Polymer tubing, made of at least one polymer layer, has a partial section of the tubing which is corrugated and wherein the rings formed by the corrugations extend around the tube axis, with the corrugations being embodied at least partially in an oval shape or in the shape of an ellipse or in the form of a circle, which is flattened on one side.

Abstract: The present invention relates to polyamide/polyvinylidine fluoride blends and multilayer tubes made therefrom. The blends have spherical morphology and a polyamide matrix with dispersed polyvinylidine fluoride phases; with the polyamide of the polyamide/polyvinylidine fluoride blend having a shear viscosity of 1.5 to 7 times greater than that of the polyvinylidine fluoride of blend.

Abstract: A highly flexible and hydrolysis and burst resistant, coolant conduit comprising a plurality of layers of different polymer compatible with one another at the contact surfaces of the layers, the conduit being at least partially corrugated and at least some of the individual adjacent corrugations being connected to each other by at least one crossbar or rib.

Abstract: A coolant conduit, which is an elongate tubular article for an apparatus requiring cooling by a cooling agent, includes a plurality of layers which are provided by, in combination, discharging a co-axial melt hose, 3D tubing manipulation, and blow molding thereof, each layer of the plurality being composed of a polymeric material which is thermoplastically processable. The plurality of layers preferably includes at least one inner layer which is composed of a polymeric material which is substantially inert to the cooling agent and which is substantially non-swelling; and an outer layer which is composed of at least one polyamide and which has a high pressure resistant which conveys a high bursting strength.

Abstract: A coolant conduit which is an elongate tubular article for an apparatus requiring cooling by a cooling agent, such as an engine, for example, an internal combustion engine, includes a plurality of layers which are provided by sequential coextrusion thereof and which are adjoined thereby, each layer of the plurality being comprised of a polymeric material which is thermoplastically processable. The plurality of layers may include an inner layer which is composed of a polymeric material which is substantially inert to cooling agent and which is substantially non-swelling, and an outer layer which is composed of at least one polyamide and which is pressure resistant. The coolant conduit may include a plurality of longitudinal sections, and at least one layer of the plurality of layers may then be composed of a polymeric material which differs between longitudinal sections thereof as is made possible by sequential coextrusion thereof.