INJECTION-MOLDED CYLINDRICAL BODY, ITS PRODUCTION, AND ROD-SHAPED DECORATIVE MATERIAL DELIVERY CONTAINER USING THE CYLINDRICAL BODY

摘要

PROBLEM TO BE SOLVED: To inexpensively provide an injection-molded cylindrical body made of a plastic having a female screw-like projection or an undercut part provided in the inner hole thereof. SOLUTION: This injection-molded cylindrical body 105 has only one female screw-like projection 133 axially formed to the inner hole thereof. The female screw like projection 133 is formed by injecting a plastic into the gap between the leading end surfaces of two mold core pins inserted into the inner hole of the cylindrical body from both ends thereof. Since it is unnecessary to rotationally draw out the core pins, mold cost is low and productivity is high.