PURPOSE: To provide core material for a door panel excellent in fire protection and the like as well as having sufficient strength in the necessary places by forming a resin reinforced part impregnated with resin and hardened, over the whole periphery of a rectangular rock wool board.
CONSTITUTION: A frame part 3 is provided being formed of a resin reinforced part 2 extended over the whole periphery of a rectangular rock wool board 1, and intermediate bars 4 are provided being formed of the resin reinforced part 2 provided in grated shape at the part other than the periphery to form core material A for a door panel. Thermosetting resin such as urethane resin is used as resin to be impregnated to form the resin reinforced part 2, and numerous fine holes are bored in the rock wool board 1 to make impregnation smooth. Resin skin layers are formed on both faces of the core material A, and surface finishing material is attached to the surface to form the door panel. With the resin reinforced part 2 provided on the whole periphery of the rock wool board 1, the peripheral part in need of strength is reinforced so as to enable sufficient use as the core material of the door panel. Heat insulation, sound insulation and fire protection can be also secured by using the rock wool board.
NISHIHAMA YOSHIHIRO
KISHIMOTO MASARU
USUI HIROAKI
YAMAGUCHI YASUNORI
TSUKAMOTO MASASUKE
KONISHI SATORU
ADACHI ARIHIRO
