Sand casting

Of the total casting output of railway casting manufacturers, 60-70% of the castings are produced by sand mold, about 70% of them are produced by clay bonded sand. More than 80% of American steel castings are made of clay green sand, more than 73% of Japanese steel castings are made of clay green sand. The main reason is that the cost of sand casting is lower than other casting methods, the production process is simple the production cycle is short. Therefore, castings such as engine cylinder block, cylinder head, crankshaft so on are produced by clay green sand process. When the wet mold cannot meet the requirements, the clay sand surface dry sand mold, dry sand mold other sand mold shall be considered. The weight of castings cast by clay green sand can range several kilograms to dozens of kilograms, while the weight of castings produced by clay dry mold can reach dozens of tons.

For large medium-sized castings, cast iron can be produced by resin self hardening sand mold cast steel can be produced by water glass sand mold. Castings with smooth size surface can be obtained, but the cost is high.

For heavy castings produced in a single small batch, manual modeling is still an important method. Manual modeling is flexible to meet various complex requirements does require many process equipment. Water glass sand mold, VRH water glass sand mold organic ester water glass can be used