Process for the production of a pipe lined with an inliner
View Patent ↗A process for the production of a pipe comprising: an interior surface having a shape; and a thermoplastic inliner is provided. The process comprises: introducing the thermoplastic inliner into the interior of the pipe; heating the pipe from the outside to a temperature higher than a crystallite melting point (T m ) of a molding composition of an exterior surface of the inliner; expanding the inliner radially in the pipe so that an exterior surface of the inliner assumes the shape of the interior surface of the pipe; and cooling the inliner; wherein a cross section of the inliner is optionally reduced through exposure to an exterior force prior to being introduced into the pipe. Relative movements between carrier pipe and inliner are thus prevented; the risk of collapse of the inliner is moreover low. The pipe is used for the production of a laid pipeline.
1. A process for producing a pipe, comprising:
introducing a thermoplastic inliner into a carrier pipe, the carrier pipe comprising an interior surface that has a shape and an exterior surface;
heating the exterior surface of the carrier pipe from the outside of the carrier pipe to a heating temperature higher than a crystallite melting point (T m ) of a moulding composition of an exterior surface of the inliner;
transferring the heat from the interior surface of the carrier pipe to the exterior surface of the inliner;
expanding the inliner radially in the carrier pipe so that the heated exterior surface of the inliner assumes the shape of the interior surface of the carrier pipe;
water cooling the inliner, thereby obtaining pipe comprising the carrier pipe and the thermoplastic inliner;
wherein
an external diameter of the inliner is at most 25% greater than an internal diameter of the carrier pipe, and
the cross section of the inliner is reduced by from 3 to 30%
the interior surface of the carrier pipe is a metal selected from the group consisting of steel, zinc and an alloy comprising aluminium, iron or zinc, and
the cross section of the inliner is reduced through exposure to an exterior force prior to being introduced into the carrier pipe.
2. The process according to claim 1 , wherein
an external diameter of the inliner corresponds to the internal diameter of the carrier pipe or is smaller by no more than 3%.
3. The process according to claim 1 , wherein
the inliner comprises at least one layer.
4. The process according to claim 1 , wherein
the inliner comprises at least two layers and
an exterior layer of the inliner is adhesion-modified.
5. The process according to claim 1 , wherein the thermoplastic inliner is made from at least one thermoplastic moulding composition selected from the group consisting of a polyamide, a polyolefin, a fluoropolymer, a polyarylene ether ketone, and a polyphenylene sulphide.
6. The process according to claim 1 , wherein the heating is maintained at the heating temperature for at least 10 seconds.
7. The process according to claim 4 , wherein the exterior layer of the inliner comprises a functionalized thermoplastic moulding composition.