The basic raw materials for making sand mold are casting sand and sand binder. The commonly used casting sand is silica sand, silica sand high temperature performance can not meet the requirements of the use of zirconium sand, chromite sand, corundum sand and other special sand. Widely used sand binder is clay, can also be used a variety of dry oil or semi-dry oil, water-soluble silicate or phosphate and various synthetic resins for sand binder. The outer sand mold used in sand casting can be divided into three types: wet clay sand mold, dry clay sand mold and chemically hardened sand mold according to the binder used in sand mold and the way of building strength.

 

 

Clay is abundant and cheap. Most of the used wet clay sand can be recycled after proper sand treatment. The casting cycle is short and the working efficiency is high. Mixed sand can be used for a long time; It's very adaptable. Small, large, simple, complex, single, large quantities can be used;

 

 

Because each sand casting can only be cast once, the casting is damaged and re-shaped after the casting is obtained, so the production efficiency of sand casting is low; The stiffness of the casting is not high, and the dimensional accuracy of the casting is poor. Casting is easy to produce sand washing, sand, porosity and other defects.