PURPOSE: To provide a mold structure, in which the quantity of waste sand produced at the time of executing reconditioning treatment can be reduced as little as possible and the mixture of crushed remained part of back sand into facing sand can be restrained and further, even after repeatedly using, the facing sand, core sand and the back sand can be improved to further sure separation and recovery.
CONSTITUTION: The facing sand layer forming a formed cavity in the mold and contacting with a prescribed molten metal is constituted with spherical mullite ceramic grains having <0.5mm grain diameter and ≤20% apparent porosity. On the other sand layer at the back of the facing sand layer is constituted with refractory grains having 0.5-3mm grain diameter and ≤13.5% crushing ratio.
SAKATA RYUTOKU
MATSUBARA MAKOTO
TODA FUMIO
| JPH0347943A | 1991-02-28 | |||
| JPH044942A | 1992-01-09 |