Abstract
The penetration of wash into sand mold is an important characteristic of the mold wash which is effective upon eliminating errosion scabs or penetration of molten metal in casting. To measure the degree of the penetration of mold wash the authors designed a method in which mold wash of carbon and clay was made to penetrate into a transparent bed consisting of round glass grains whose grain size ranged from 50 to 90 meshes. For preparing mold wash coke, earth graphite and flake graphite were used as carbon material and kaolin and bentonite as clay material. The experimental results were as follows: 1) The method of measuring the penetration of mold wash by using the transparent cylinder containing round glass grains proved to be sufficiently useful. 2) The depth and rate of penetration and separation of water from the penetrated wash were easily measured from outside. In this case, there was found a close corelationship between the penetration of wash into the glass grain bed and that of wash into ordinary sand mold. 3) The degree of penetration was inversely proportional to the viscosity of wash which was varied by the water content of the wash. 4) The degree of penetration was varied with the ingredients of wash. Particularly, it was noticed that only in case earth graphite (natural amorphous graphite) was used, penetration was promoted by increasing the content of clay added to the graphite wash.
