| 摘要 |
PURPOSE:To constitute the title method so that a sink corresponding to a thick part is not generated on an external appearance side even if a thick part such as a rib is on the inside, by a method wherein an appropriate number of platelike pieces are fitted beforehand under a state where a rib forming recessed part of a mold is closed partly and in a dispersed state and then RIM molding is performed. CONSTITUTION:Three sheets of platelike pieces 5 are fitted to a male mold 2 (ordinarily this become a top force) forming the inside of a molded product at intervals so that they close partly and in a dispersed state a recessed part 4 to form a rib 3. A cavity 7 is formed of the male mold (top force) 2 and a female mold (bottom force) 6 by putting them together and RIM molding resin is cast under low pressure. At a buried position of the platelike piece 5 an influence of contraction following cooling and solidification of the rib 3 is interrupted by the platelike piece 5 so that an ordinary thick part, 8 is not influenced by separating the ordinary thick part 8 and rib 3 partly from each other by the platelike piece 5. Therefore, the external side of the ordinary thick part 8 develops no sinks 9. |
