| 摘要 |
PURPOSE:To make it possible to control strength in response to site by a method wherein reinforcing fiber material, to which magnetic material particles are stuck, is kneaded with molten plastic matrix and, after that, injected in a mold and finally attracted to the site, which is wanted to be reinforced, of a molded item before the hardening of the plastic matrix by means of magnets annexed to the mold. CONSTITUTION:Mixed pellets 4, which consist of glass fibers 1 bitten by ferrite particles 2 and polypropylene 3, are heated with heating means 10 in an injection cylinder 9 so as to be injected at high speed in a tightly closed mold 6, with a screw 11 under molten polypropylene 3. As for the polypropylene 3 and glass fibers 1 injected in the mold, by energizing electromagnets 7 annexed to the mold 6 just before said injection, glass fibers 1 bitten by ferrite particles 2 are magnetically attracted to the electromagnets 7 annexed to the mold 6 before the hardening of the polypropylene 3. As a result, the density of the glass fibers 1 becomes higher near the electromagnets 7 annexed to the mold 6 and the local strength of the highly densified site can be enhanced positively. |
