| 摘要 |
PROBLEM TO BE SOLVED: To provide a resin manhole cover having high strength while suppressing use of resin members.SOLUTION: A resin manhole cover comprises a reinforcement rib having a honeycomb structure, on the rear side. As resin, thermoplastic resin is mainly used, and engineering plastic such as polycarbonate, polyamide, and modified polyphenylene ether is used. Ejecting the resin to a mold forms a manhole cover comprising a rib having a honeycomb structure, on the rear side. Thereby, both improvement of load bearing and weight saving are implemented in the resin manhole cover.SELECTED DRAWING: Figure 2 |
