| 摘要 |
PURPOSE: To enhance tensile and bending breaking strength while stabilizing quality by injecting a fiber-containing thermoplastic synthetic resin compsn. into a cavity from a gate to branch and fluidize the same within a resin molded product and putting the characteristics of a resin association part to practical use to largely change the orientation of the fiber in the reinforcing direction of the product. CONSTITUTION: A fiber-containing thermoplastic synthetic resin compsn. is injected into an injection mold by an injection means to mold an injection- molded product of a cylindrical test piece. In the injection process of the cylindrical test piece, when the injection of a molten resin into a product part cavity part 4 is simultaneously started from the gates 3A, 3B provided to a symmetric position with respect to the center axis of the region 4A corresponding to a flange part, a weld W is generated in the flange part 4A and a resin flows. As a result, the fiber in the molten resin is strongly oriented in the direction parallel to the center axis being the flow direction of the resin to largely enhance strength against tensile load. When the wt. average fiber length in the molten resin is large, this tendency becomes more marked. |
