| 摘要 |
PURPOSE:To reduce incompletely bonded sections of a resin layer to a metal tube, improve the durability and reduce the peeling of resin at the time of secondary processing by plasma welding the butt section of the metal plate. CONSTITUTION:Both side edges of a belt-shaped metal plate 10 are formed into the cylindrical shape in a manner of butting together. Simultaneously the both side edges are bonded together to manufacture a metal tube 12 continuously. A resin extrusion mold 71 is inserted from an opening being molded into the metal tube 12, and resin P in the molten state is extruded toward the inner face of the metal tube 12 after bonding. A composite tube 13 with its face, originally the inner face of the metal tube 12, coated with resin P is manufactured by the arrangement. The butt section of the metal plate is plasma welded by a plasma welder 6 and bonded. As the plasma welding is used for bonding the both side edges of the metal plate as above-mentioned, the range affected by the welding high temperature section is narrow, and the breakage area of a primer composition is approximately several mm. |
