一般在造型用原材料中,水玻璃与含脂是作为粘结剂分别加入型砂或芯砂中的。而对干小型厚壁铸件的小型复杂的砂芯,我们最近在生产中应用了水玻璃——合脂系芯砂,该种芯砂除了成型性好、具有一定的湿干强度,而且耐火度较高、压溃性较好,更主要的是其具有易清砂性。该芯砂的配比如下表(重量比): Generally used in molding raw materials, water glass and fat are added as a binder, respectively, sand or core sand. For small and complex sand cores of dry small thick-walled castings, we recently applied sodium silicate-sealant core sand in the production. In addition to good formability, the core sand has a certain degree of wet-dry strength, and the refractoriness Higher, crushing better, more important is its easy to clean sand. The core sand ratio shown in the following table (weight ratio):