| 摘要 |
PURPOSE:To enable the manufacture of the product without sink marks in a thick section part to be achieved by heating the mold surfaces corresponding to the side surface of the thick section part and the upper and lower surface of a thin section part, when the plate like product having the side surface of the thick section part and the thin section part is pressed and cooled. CONSTITUTION:At molding a plate like product, after molds 4 and 5 have been preheated to the temperature equal to or higher than the crystallization beginning temperature of crystalline resin stock 14 o be molded, the female mold 5 and the male mold 4 are pressurized under 2- 10kg/cm<2> pressure by a pressing machine. Saidmolds are continuously cooled, while filling the stock 14 in the portions which are to become a thick section part and a thin section part after molded. At this cooling time, the cooling and solidifying speed on the side surface of the molded article and the upper and lower surfaces of the thin section part of a molded article are regulated by the intervening of heating elements. Conversely, the cooling of the upper and lower surfaces of the thick section part are accelerated. Therefore, the cooling and solidifying speed of the thin section part to the center of molten resin is suppressed, and the cooling and solidifying of the side surface of the thick section of a molded plate are also controlled. Accordingly the upper and lower surfaces of the thick section part or its side surfaces are solidified, while the center of the thick section part is yet in unsolidified state, whereby no sinkmark occurs. |
