COMPOSITE PLASTIC PIPE

Abstract: Composite plastic pipe, characterized in that it principally consists in the combination of an extruded pipe in thermoplastic synthetic material and a pultruded pipe or pipe obtained by pull winding in thermoplastic or preferably thermo-hardening synthetic material which fit closely.

Description: Composite plastic pipe. The present invention relates to a composite plastic pipe. It is known that ordinary plastic pipes, generally extruded plastic pipes in thermoplastic material, such as polyvinyl chloride, polypropylene, high-density polyethylene and similar are very suitable for transporting liquids since they are not only watertight but are also resistant to chemically corrosive products. The disadvantage of these known pipes is however that they cannot offer sufficient resistance to very high pressure loads so that the transport of liquids under high pressure is excluded. It is also known that plastic pipes, generally pultruded plastic pipes in thermoplastic, but preferably ther o-hardening material, such as polyester, vinyl ester, epoxy, and similar are very well suited to resisting pressures. The disadvantage of the latter type of pipe is however that, through the presence of fibres in the plastic the watertightness thereof cannot be guaranteed, among others because liquids which could be transported through such pultruded and/or pull winding plastic pipes " leak away along fibres which in one way or another offer a passage from one side of the plastic pipe to the other side of it. The object of the present invention is a composite plastic pipe which totally excludes the aforementioned disadvantages of known plastic pipes and whereby a pipe is obtained which is not only watertight and suitable for transporting chemically corrosive products, but which is at the same time capable of transporting such liquids under a high pressure. Yet an additional advantage is that in this manner a plastic pipe is obtained which shows a very great impact resistance. The composite plastic pipe according to the invention which shows the aforementioned and other characteristics for this purpose principally consists in the combination of an extruded pipe in thermoplastic synthetic material and a pultruded pipe or pipe obtained by pull winding in thermoplastic or preferably thermo- ardening synthetic material which fit closely. In a particular embodiment the external surface of the the inner pipe, respectively the internal surface of the outer pipe will be produced rough in order to obtain that these pipes exert an anti-rotating effect in relation to each other all of which such that the composite pipe obtains a very great resistance against torsion. The aforementioned external surface of the inner pipe, respectively internal surface of the outer pipe, can for this purpose be produced corrugated or similar whereby the corrugations, notches or similar of the aforementioned surfaces interconnect. Although such working together of the surfaces of inner pipe and outer pipe is preferable this is not restrictive yet a very good result can also be obtained with pipes of which the cooperating surfaces are produced smooth. A composite pipe according to the present invention will preferably be obtained by an inner pipe in a thermoplastic, for example polypropylene, polyvinyl chloride, high-density polyethylene, polyamide or similar, by effecting extrusion, after which an outer pipe is formed around the thus formed inner pipe by pulling fibres or fabrics soaked in a thermoplastic or thermo-hardening synthetic material, for example in polyester, vinyl ester, epoxy or similar, through a heated die, in other words by pultruding around the thus formed inner pipe. Obviously the composite pipe according to the invention can also be produced by a pultruded inner pipe with an extruded outer pipe around it. In order to show better the characteristics according to the present invention, a preferred embodiment is described hereafter, as example without any restrictive character, with reference to the enclosed drawings, in which: figure 1 shows a radial section through a composite plastic pipe according to the invention; figure shows on larger scale and for an embodiment variant the part that is indicated by F2 in figure 1 ; figure 3 shows a variant of figure 2. In figure 1 a composite plastic pipe 1 according to the invention is shown which is principally formed by an inner pipe 2 in a thermoplastic material, for example polypropylene, pol vinyl chloride, high-density polyethylene or similar which is obtained by extrusion and an outer pipe 3 in a thermoplastic or thermo-hardening material, for example polyester, vinyl ester, epoxy or similar which is obtained by pultrusion and/or pull winding and which is installed close-fitting around the inner pipe 2. An inner pipe is thus obtained which is tight and through which chemically corrosive products can be transported with an outer pipe around it which is very impact resistant: and which can resist high pressures. In figure 2 it is indicated that the inner surface of the outer pipe, on the one side, and the outer surface of the inner pipe, on the other side can be produced smooth or rough in order to provide such a pipe with a very effective resistance against torsion. Such rough surfaces can for example be obtained by extruding the inner pipe 2 with corrugations 4 extending according to the longitudinal direction of the pipe around which the outer pipe 3 is pultruded, all of which such that the internal surface of the 3 automatically takes on the form of the outer surface of the pipe 2. Other shapes for obtaining an interconnection between the pipes 2 and 3 are obviously also possible, such as transverse notches for example, which ensure the connection in the longitudinal direction and similar. In figure 3 it is finally still shown that it is also possible to combine an externally smooth inner pipe with an internally smooth outer pipe. It is clear that the present invention is in no way restricted to the embodiments described above and shown in the enclosed drawings, but such composite plastic pipe can be implemented in all kinds of forms and dimensions without departing from the scope of the invention, such as a composite with plastic/metal, ferrous and nonferrous, and interchangeable.

Claims: Claims. 1.- Composite plastic pipe, characterised in that it principally consists in the combination of an extruded pipe in thermoplastic synthetic material and a pultruded pipe or pipe obtained by pull winding in thermoplastic or preferably ther o-hardening synthetic material which fit closely. 2.- Composite plastic pipe according to claim 1, characterised in that the extruded pipe is the inner pipe (2) and the pultruded pipe or pipe obtained by pull winding is the outer pipe (3). 3.- Composite plastic pipe according to claim 1, characterised in that the extruded pipe is the outer pipe (3) and the pultruded pipe or pipe obtained by the pull winding is the inner pipe (2). 4.- Composite plastic pipe according to one of the preceding claims, characterised in that the inner pipe (2) shows a rough surface with which the outer pipe (3) interconnects. 5.- Composite plastic pipe according to claim 4, characterised in that the inner pipe (2) shows protruding corrugations (4) extending according to the longitudinal direction thereof with which the outer pipe (3) interconnects. 6.- Composite plastic pipe according to claim 4, characterised in that the inner pipe (2) shows notches with which the outer pipe (3) interconnects. 7.- Composite plastic pipe according to one of the preceding claims, characterised in that one pipe is produced in a thermoplastic such as polypropylene, pol vinyl chloride, high-density polyethylene, polyamide. LLD, PE, etc... while the second pipe is produced in ther o- ardening materials such as polyester, epoxy, vinyl ester, etc... 8.- Composite plastic pipe according to one of the preceding claims, characterised in that it is produced as a composite/plastic/metal, ferrous and nonferrous, and can be exchangeable both in smooth and corrugated surfaces.

Inventors: DIERICKX PATRIECK, DIERICKX, PATRIECK
Applicants: JONACO GMBH
Application year: 1990
Main classification: F16L9
IPC codes: B29C70, B29D23, B29K105, F16L9