| 摘要 |
PURPOSE:To efficiently manufacture a blow-molded product, having an opening narrower than a hollow part, by an injection molding for a thermosetting resin, by the use of a core made of a metallic salt having a particular comparatively- low melting point. CONSTITUTION:A metallic salt, such as a mixture of 45wt% sodium nitrite, and 55wt% potassium nitrate (melting point; 142 deg.C), which prevents a cured resin from the production of a change in properties and the occurrence of pyrolysis and is molten at a comparatively-low temperature, is used. That is, a core made of said metallic salt is placed in a mold 2, and a molten thermosetting resin is pressed in a formed cavity 21 through a gate 4. After the resin is cured, it is removed from a mold 2, a thermosetting resin molded product 3 is heated at higher than a melting point of said metallic salt together with a core 1, and the molten core 1 is removed from the molded product 3 to obtain a blow-molded work serving a product. |
