| 摘要 |
PURPOSE:To produce a uniform spread and flow of a molten resin, by allowing a relatively large resistance to act on the flow in a cavity gap corresponding to a place where a distance to the circumferencial part is short when a molten resin injected at a roughly central position of the rear face side spreads and flows in a circular shape along the rear face. CONSTITUTION:Resistances to flow of a molten resin are made different, in a cavity gap corresponding to positions 1a, 1a... where the distance l1 from the resin injection position of an in-flowing gate 12 to the circumferencial part of a main body of a molding 1 is short, and in a cavity gap corresponding to position 1b where the distance l1 is long, from each other and the difference in resistance to flow is made in such a way that it is larger at the positions 1a, 1a... where the distance l1 is shorter than at the position 1b where the distance l1 is long. The molten resin 2 covering over the rear face of the main body of the molding flows into a cavity gap 11d of the front face side almost simultaneously from the whole circumferencial side through a cavity gap 11c of the circumferencial side face, and gaps which may otherwise generate by catching air bubbles do not occur at the frame part of the bottom side which is visible from the outer surface. |
