1. Technical Field
The present invention relates to a synthetic resin molding used as an automotive interior decorative component, such as an automotive trim, and a molding method for the synthetic resin molding.
2. Description of the Background
Synthetic resin moldings used as automotive interior decorative components may be injection-molded pieces with a high quality appearance of metallic luster using a metallic colored resin material, which is a resin material into which a luster agent containing metallic powder, such as aluminum powder, has been kneaded.
A synthetic resin molding formed by injection molding can typically have weld lines, or flow lines, resulting from a disturbed flow of the molten resin. For a molding formed using a metallic colored resin material, in particular, a disturbed flow of the molten resin can disturb the orientation of the luster agent. This destabilizes the color tones and cannot produce intended design effects.
Techniques have been known to prevent such weld lines in synthetic resin moldings formed by injection molding. One such technique described in, for example, Japanese Unexamined Patent Application Publication No. 7-304071 (hereinafter referred to as “Patent Literature 1”) allows the resin injected through a plurality of gates to flow uniformly along a continuous thin portion on a back surface portion of a molding corresponding to the gates.