With the rapid development of science and technology and industrial production, the application scope of investment casting technology is expanding. Compared with the rapid development of investment casting industry, the performance and quantity of wax are difficult to synchronize. Therefore, various organic substances, plastics and inorganic salts have been used one after another. Some are added to the wax as filler, and some are formed directly instead of wax. Therefore, wax molds and waxes are gradually replaced by molds and investment molds.
Waxes for casting are generally divided into low temperature wax, medium temperature wax and high temperature wax. Due to the time required for production, high-temperature wax is seldom used. Generally speaking, low temperature wax is used for sand casting and medium temperature wax is used for precision casting.
Medium temperature wax. It is mainly rosin wax based mold materials and filling mold materials. The melting point is between 70-100 ℃, with high strength, good thermal stability (35 ℃), small shrinkage, good dimensional stability, good surface roughness and good replication performance. It can be reused, the preparation process is complex and the cost is high. Dewaxing can be carried out with water, steam or microwave. This mold material is usually used with silicone adhesive. Generally, it is produced by waxing machine.
At present, the silica sol shell process of wax mold at medium temperature is the mainstream technology in the production of precision castings at home and abroad. However, due to the defects of the surface shell, the current shell manufacturing cycle is very long. It is suggested to add anti crack agent in the surface glue, dry the surface layer with large particle size silica sol, cancel the two layers of coating and two layers of pre wetting, cancel the process measures such as silica sol before coating, improve the surface strength, reduce surface defects, shorten the drying time of the coating film, and improve the one-time coating film qualification rate.
The precision casting of medium temperature wax is combined with the manufacturing process of silica sol shell, while the low temperature wax is generally combined with the manufacturing process of water glass shell. It is characterized by small line shrinkage and simple use of equipment. In the hot processing industry forum, it is different from the wax treatment of medium temperature model wax. Medium temperature wax is dehydrated and purified, and low temperature wax is a reaction treatment to remove saponification.
Generally speaking, the medium temperature wax is combined with the silica sol shell manufacturing process, while the low temperature wax is generally combined with the water glass shell manufacturing process! As the low-temperature wax contains water vapor, the shrinkage of the medium temperature wax is greater than that of the low-temperature wax. If there is a difference, the size of medium temperature wax is more stable than that of low temperature wax, and the price is a little more expensive.
Qingdao Xinnuoke Holdings Group limited company.