| 摘要 |
PURPOSE:To produce a thin-walled casting having good airtightness, dimensional accuracy and casting surface by packing molding sand into a pattern coated with a liquid compounded with a suitable ratio each of a liquid contg. an acidic silica sol and liquid contg. an alkaline hardener to form the surface part of a casting mold contg. aggregate and having beauty and adequate strength then executing low-pressure casting. CONSTITUTION:The liquid adequately compd. with the silica sol liquid prepd. by adding ethyl silicate and water to an alcohol solvent and adding an acid thereto and the alkaline hardener contg. NaOH, etc. and having about 7.5-11.5pH in such a manner that refractories settle satisfactorily and cure in a prescribed period is prepd. Such liquid is coated on the pattern and the molding sand is packed therein to form the surface part of the casting mold contg. the molding sand aggregate and having the beauty and adequate strength after the prescribed time. The run is improved in spite of the high cooling power and the thin-walled casting having the airtightness, dimensional accuracy and beautiful casting surface is obtd. if the casting is executed by bottom pouring and low-pressure casting with such casting mold. |
