| 摘要 |
PURPOSE:To cover both surfaces of a core material with uniform thickness resin layer by preventing deformation of the core material, by a method wherein a positioning protrusion of a mold is inserted into a positioning hole of the disklike core material having a resin circulation hole on the central part and molten resin is charged into a cavity by pressing the core material from both the surfaces. CONSTITUTION:A positioning pin 25 of a stationary mold 11 is inserted into a positioning hole 32 of a core material 30. Sprue 17 is filled with molten resin through an injection machine in a mold clamping state, the molten resin arrives at the central part of a cavity 15, abuts against a bushing 18 and ejector pin 19 through a resin circulation hole 31 of the core material 30 and charged toward the fringe of the cavity 15 through a space among the core material 30 and each of mold surfaces 13a, 14a. Therefore, injection pressure is hardly applied to the surface of the core material 30 and a deformation can be prevented. As both surfaces of the core material 30 are pressed by press pins 26, 28, the core material 30 can maintain a state wherein the same runs parallel with both the mold surfaces 13a, 14a and a resin layer 52 covering both the surfaces of the core material can be made into a uniform thickness extending over the whole surface. |
