Steel casting , iron casting and great majority non-ferrous alloy castings can be got by sand mold casting . For a long time , sand mold casting is always the basic technology in foundry practice as a result of the low-cost molding material , means simple and efficient , adapt to also single-piece production , batch production and mass production.
Sand mold is produced mainly from foundry sand and molding sand binder , can be divided into three kinds : clay green sand mold , clay dry sand mold and chemical hardening sand mold.
Clay green sand mold : the source of clay plentiful and cheap , can be recycle , cycle short and high efficiency , working life long.
Clay dry sand mold : commonly is used to produce steel casting or larger iron casting . But it has mainly been eliminated because of chemical hardening sand mold.
Chemical hardening sand mold : higher accuracy of castings ; sand blender low power and high production rate ; don’t need hugeness and intricate molding machine ; can choose foam material depends on production requirement ; the surface of sand mold and mold core should apply an excellent coating ; use sodium silicate as binder is low cost and no objectional odor , but can’t direct recycle ; use resin as binder is high cost but can direct recycle.