| 摘要 |
PROBLEM TO BE SOLVED: To make a coating agent keep the original shape even after losing a lost pattern and to prevent the sand-burning by spreading and sticking stick particles on the surface of the refractory coating agent coated on the surface of the lost pattern to form the two layers consisting of the refractory coating agent layer and the stick particle layer on the pattern surface. SOLUTION: The refractory coating agent is applied on the surface of the lost pattern 1, and while the coating agent layer 4 is not yet dried (in the state where the spread stick particles 5 are stuck on the surface of the coating agent layer 4), the stick particles 5 are spread so as to cover the whole surface of the coating agent layer 4. After drying the coating agent layer 4, the excess stick particles are dropped. When this lost pattern is embedded into the molding sand, the stick particles 5 and the molding sand 6 are mutually fitted and the coating agent layer 4 becomes the state supporting the molding sand 6 through the stick particles 5. Successively, molten metal is poured to manufacture a casting. At this time, the lost pattern 1 is lost with the heat of the molten metal, but the coating agent layer 4 is not exfoliated and left on the surface of the molding sand 6 and thus, the action for preventing the sand- burning of the coating agent itself is exhibited.
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