초록 ▼

A method for the production of a composite pipe with at least the inner surface thereof covered with a plastic layer, comprising: forming a coiled metal sheet into a cylinder, during the conveyance of the metal sheet, by a cylindrical inner mold and at least one of a plurality of outer molds lined u

A method for the production of a composite pipe with at least the inner surface thereof covered with a plastic layer, comprising: forming a coiled metal sheet into a cylinder, during the conveyance of the metal sheet, by a cylindrical inner mold and at least one of a plurality of outer molds lined up in the direction of conveyance of the metal sheet, said outer mold having a housing composed of two separatable parts and being fitted around said inner mold with a fixed space; joining the side edges in the circumferential direction of said cylinder together; and extruding molten resin into a cylindrical shape over the inner surface of the cylinder from the inner mold, resulting in a composite pipe the inner surface of which is covered with a plastic layer.

대표청구항 ▼

A method for the production of a composite pipe with at least the inner surface thereof covered with a plastic layer, comprising the steps of: forming a coiled metal sheet into a cylinder, during the conveyance of the metal sheet, by a cylindrical inner mold and at least one of a plurality of outer

A method for the production of a composite pipe with at least the inner surface thereof covered with a plastic layer, comprising the steps of: forming a coiled metal sheet into a cylinder, during the conveyance of the metal sheet, by a cylindrical inner mold and at least one of a plurality of outer molds lined up in the direction of conveyance of the metal sheet, said outer mold having a housing composed of two separable parts and being fitted around said inner mold with a fixed space wherein the inner surface of each of the parts of said housing is provided with a half-cylindrical liner which can be attached thereto and detached therefrom, in such a manner that said liner fits over said inner mold with a fixed space; joining the side edges in the circumferential direction of said cylinder together; and extruding molten resin into a cylindrical shape over the inner surface of the cylinder from the inner mold, resulting in a composite pipe the inner surface of which is covered with a plastic layer.