PURPOSE: To improve shearing adhesive force of a metal tube and a synthetic resin tube and to obtain an inner surface synthetic resin lining metal tube of high quality by inserting the synthetic resin tube coated on its outer surface with adhesive along from one end to its inner surface of the metal tube, and then contracting the metal tube while heating it.
CONSTITUTION: A metal tube 1 is first pretreated on its inner surface by pickling or blasting, and necked at its one side end. Then, a synthetic resin tube 3 coated on its outer surface with adhesive is inserted from one side end of the tube 1 along its inner surface, and supported by a plurality of support rolls 4. Subsequently, the tubes 1, 3 are sequentially inserted into a necking die 5 and a heater 6, and then grasped by a gripper 7. The tube 1 is heated by the heater 6, and an outer diameter of the tube 1 is then contracted by the die 5, thereby manufacturing an inner surface synthetic resin lining metal tube. Thus, at the time of contracting the tube 1, it prevents crack of the tube 3 and generation of a gap in a boundary between the tubes 1 and 3.
ISHIDA MASAMI
SASAKI TOSHIYUKI
