| 摘要 |
PURPOSE: To obtain a blow resin molded product having such a structure that the side wall thick-walled part of a hollow part is provided and the hollow part is still more reinforced by arranging piercing recessed parts to the thick- walled part and capable of being smoothly demolded without generating deformation and damage by gas injection molding. CONSTITUTION: Side wall thick-walled regions 5 and side wall thin-walled regions 6 are alternately formed in the hollow part 10 of a blow resin molded product in an unopposed state so as to hold the longitudinal center axis of the hollow part therebetween and piercing recessed parts 4 are provided to the thick-walled regions 5. At the time of gas injection molding, the projections provided to the cavity surface of a mold corresponding to the piercing recessed parts 4 become resistance against the flow of a thermoplastic resin and, since gas is injected in this state, thick-walled regions 5 are formed around the projections. At the same time, thin-walled regions 6 relatively thinner than the thick-walled regions are formed to both ends of the thick-walled regions 5. |
