MANUFACTURE OF PLASTIC INJECTION MOLDED PRODUCT HAVING REVOLVABLE CONNECTION PART

摘要

PROBLEM TO BE SOLVED: To provide a method for efficiently manufacturing a plastic injection molded product having a hinge connection mechanism of a valve or a socket part and other revolvable connection part. SOLUTION: The outer periphery of the connection hinge pin of a preliminarily molded revolving member is covered with a cylindrical body 4 composed of a water-soluble plastic and the whole is set to the interior of a main body mold at a predetermined position to perform injection molding to mold an injection molded product wherein the support hole part 1b of a hinge 2a is formed in such a state that the cylindrical body 4 is integrated and the cylindrical body 4 composed of water-soluble plastic is dissolved and removed or a main body is preliminarily molded to fit the cylindrical body 4 composed of water-soluble plastic in the inner periphery of the support hole part 6 of the hinge pin 2a and the whole is set in the mold on the side of the revolving member at a predetermined position to perform injection molding and the cylindrical body 4 is dissolved and removed to form a connection part wherein the hinge pin 2a is revolvable in the support hole part.