HOLLOW MOLDED ITEM AND DIE DEVICE FOR MANUFACTURING THE SAME

摘要

PROBLEM TO BE SOLVED: To enhance the strength by manufacturing a leg for a chair including a bar-shaped horizontal part extending radially by a gas-aided injection molding method. SOLUTION: A nozzle 14 for blowing a gas to expand a molten synthetic resin into a hollow form is projected toward a cavity in a lower die 10 and a recess 19 is formed at an area of the nozzle 14. By providing the recess 19, a cylindrical rib 21 is formed in a hollow molded item 5 so as to surround a hole 20 from which the nozzle 14 is drawn out. Thus a break due to the concentration stress on the periphery of the hole 20 can be prevented so that the strength can be enhanced.