What is the production process of water glass sand

In the casting industry, especially in the production of cast steel and cast iron parts, the sand casting process is a highly critical molding method. Among them, the water glass sand process has occupied a place in the market with its unique advantages.

1. Principle of water glass sand process

The core of the water glass sand process is to use water glass (sodium silicate solution) as a binder to bond raw sand, such as quartz sand, together and form high-strength and high-toughness casting sand through a curing reaction. During the casting process, water glass reacts chemically with a specific hardener (such as an acid catalyst or organic ester) to form a water-insoluble silicate consolidation body. This consolidation body not only has high strength and hardness but also ensures that the casting has good dimensional accuracy and surface quality.

2. Composition of water glass sand production line

The water glass sand production line is usually composed of multiple key equipment to ensure the smoothness and efficiency of the entire casting process. The following are the main components of a typical water glass sand production line:

Sand mixing equipment: The sand mixer is one of the core equipment of the water glass sand production line, which is used to evenly mix materials such as raw sand, water glass and hardener. Common types of sand mixers include continuous sand mixers and intermittent sand mixers. Continuous sand mixers are suitable for large-scale production, with the advantages of high production efficiency and uniform sand mixing. In contrast, intermittent sand mixers are ideal for small-batch production or experimental production.

Molding equipment: The molding machine is used to fill the mixed water glass sand into the mold and form the required casting mold through compaction, vibration and other process steps. Standard molding equipment includes a vibration table, flip mold machine, etc. This equipment can ensure the compactness and dimensional accuracy of the casting mold, thereby improving the quality of the casting.

Drying equipment: The drying kiln is used to dry the water glass sand casting mold to remove moisture and volatile substances. The drying process is essential to improve the strength and stability of the casting mold. Standard drying equipment includes surface drying kilns, tunnel drying kilns, etc.

Pouring equipment: The pouring system is used to inject molten metal into the mold that has been dried and hardened. The pouring process requires strict control of the temperature and flow rate of the molten metal to ensure the quality of the casting. Standard pouring equipment includes ladles, pouring machines, etc.

Cleaning equipment: After the casting is cooled, it needs to be taken out of the mold and cleaned. Cleaning equipment includes sand dropping machines, shot blasting machines, etc., which are used to remove impurities such as molding sand and oxide scale on the surface of the casting.

3. Water glass sand process steps

The water glass sand process mainly includes the following key steps:

Raw material preparation: According to the requirements and process characteristics of the casting, select suitable raw sand, water glass, hardener and other materials. The quality of raw sand has a significant influence on the strength of the casting, so its performance indicators need to be strictly controlled.

Sand mixing: Add raw sand, water glass, hardener and other materials to the sand mixer in a particular proportion for mixing. During the mixing process, parameters such as sand mixing time and sand mixing temperature need to be controlled to ensure uniform mixing and achieve the required process performance.

Molding: Fill the mixed water glass sand into the mold and form the required casting mold through compaction, vibration and other process steps. During the molding process, parameters such as the compactness and dimensional accuracy of the casting need to be controlled.

Drying: Put the casting mold into the drying kiln for drying to remove moisture and volatile substances. Parameters such as drying temperature and time need to be adjusted according to the material and size of the casting.

Pouring: Inject the molten metal into the mold that has been dried and hardened. During the pouring process, parameters such as the temperature and flow rate of the molten metal need to be controlled to ensure the quality of the casting. At the same time, attention should also be paid to prevent safety issues such as splashing or overflowing of the molten metal.

Cooling and cleaning: After the casting is cooled, it needs to be removed from the mold and cleaned. During the cleaning process, impurities such as molding sand and oxide scale on the surface of the casting need to be removed, and necessary inspection and repair work needs to be carried out.

4. Advantages and applications of water glass sand process

The water glass sand process has significant advantages in the production of steel and iron casting parts:

High strength and high toughness: The water glass sand casting has high strength and toughness and can withstand more significant casting pressure and impact force, thereby ensuring the quality of the casting.

Good yield: The water glass sand casting can undergo certain deformation and shrinkage during the casting process to adapt to the solidification and shrinkage process of the molten metal, thereby avoiding defects such as cracks in the casting.

Excellent disintegration: The water glass sand casting is easy to disintegrate into fine granular substances after pouring, which is convenient for subsequent cleaning and recycling. It helps to reduce production costs and improve production efficiency.

Wide range of applications: The water glass sand process is suitable for the production of castings of various complex shapes and sizes, especially in the fields of high-speed rail, subway, mining, wind power and other equipment parts and gearbox component assemblies.

In summary, the water glass sand production line and process play an essential role in the production of cast steel and cast iron parts. By rationally selecting raw materials, optimizing process parameters and strengthening on-site management, the quality and production efficiency of castings can be further improved, providing strong support for the sustainable development of enterprises.