| 摘要 |
PURPOSE:To prevent undulations from occurring inside a tubular body by pressing the tubular body placed between a resin extruded section and a cooling section to the inner layer extruded and fuse-welding uniformly the resin inner layer and the resin outer layer. CONSTITUTION:As the synthetic resin inner layer P1 and the synthetic resin outer layer P2 are moved by the mold 1, they are passed along the outer circumference section of the tubular body 4 to keep the shape of the synthetic resin inner layer 1, to correct the wall thickness uniformly and to modify the fuse welding state uniformly. Then, they are passed along the circumference of the cooling section 3, cooled, hardened and released from the mold. The inside undulations of the synthetic resin inner layer are corrected flatly, too. |
