| 摘要 |
PURPOSE:To decrease casting defects by packing dried refractory particles into a pattern, adding water to the surface thereof and heating a casting mold together with the pattern to dry. CONSTITUTION:A proper amt. of water glass is added as a water soluble binder to silica sand and is dried to form refractory particles. The water is sprayed to the inside surface of the cavity of the pattern 1, then the dried refractories are packed into the cavity to form the casting mold 2. The refractory particles have good fluidity and are therefore closely packed into the cavity having an intricate shape. The casting mold 2 together with the pattern 1 is put into a heating and drying furnace 4 where the mold in the cavity is heated to dry. The moisture in the binder on the surface of the mold 2 is evaporated and a hardened layer 3 is formed. The chipping, etc. of the casting mold are therefore eliminated and the casting defects are decreased.
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