| 摘要 |
PURPOSE:To secure an appropriate molding circumstances for packages under all sorts of conditions, by a method wherein a gate and cavity are opened so that they are communicated respectively with both a top and bottom forces of a molding tool. CONSTITUTION:An upper and lower gates 7, 5 are opened respectively on both a recessed position 3a of a top force 1 and a recessed position 3b of a bottom force 2, in a side wall of a cavity 3. As resin 21 to be cast into the cavity 3 is applied in a symmetric form vertically, filling rates at the recessed position 3a of the to force 1 and the recessed position 3b of the bottom force 2 become almost equal to each other. In this instance, as an upper air vent 10 and lower air vent 9 are opened respectively on the recessed position 3a of the top force and the recessed position 3b of the bottom force in the cavity 3, air in the inside of the cavity 3 which has been entrapped by filling of the resin is discharged about equally vertically. Consequently, generation of defects such as an air entrapment phenomenon and a local unfilling phenomenon of the resin is prevented. |
