FINISHING METHOD FOR INJECTION MOLDED PRODUCT

PURPOSE:To close a sprue hole easily with a small amount of manhour, by a method wherein a surrounding wall surface of a sprue of a molded product is designated so as to recess the same lower than a circumferential wall surface of the peripheral wall surface, the hollow sprue is removed flush with the wall surface after molding and a plug made of a plastic material provided with a radial fin is driven into an opening generated on the removed surface. CONSTITUTION:A wall surface 18 of a molded product in a region where a sprue 17 is formed is designed in a recessed state lower than its surrounding wall surface 19. The sprue 17 is removed so that the same becomes flush with the wall surface 18 and an opening 20 is formed, in a taken out molded product 14. A dislike head part 22 is provided with a large number of fins 23 extending radically in an axial direction from the head part 22. A plug 21 made of a plastic material is driven into the opening 20. The fin 23 is compressed and deformed elastically, an undercut part is formed directly below the head part 22, connected reliably with the opening 20 and the opening 20 is closed with the plug 21.