Classification of moulding sand:
According to different binders, molding sand can be divided into:
(1) Clay sand
(2) water glass sand
(3) resin sand
(4) oil sand and resin sand.
Resin sand technology is a great change in foundry technology. It uses “resin” as a cleaning agent, which makes foundry technology step up in all aspects.
There are many kinds of resin sand technology, such as shell core, hot core box, cold core box, self hardening sand and so on. We adopt “furan resin self hardening sand technology”. Furan resin self hardening sand process is not only suitable for simultaneous interpreting in large quantities, but also for single, multi variety and small batch production. Compared with traditional clay sand, it has the following advantages:
High dimensional accuracy, low surface roughness, saving energy, improving labor productivity, improving working conditions of workers, high reuse rate of used sand, small environmental pollution and so on.
The process has been introduced into China since 1980, especially the input of production line and the solution of raw material problems related to technology. It develops very fast in our country, especially in machine tools, shipbuilding, heavy machinery, electrical and other industries, and has achieved good results. But it also has its own limitations. When casting thin-walled carbon steel castings, because of its high temperature strength, it is easy to produce cracks. This is absolutely out of line for nuclear power valves. At the same time, there is a problem of casting surface carburization. It is better not to use this process for the production of ultra-low carbon stainless steel.
Modeling methods are divided into manual modeling and machine modeling: manual modeling is suitable for single piece, small batch production. According to the characteristics of the sand box, it can be divided into two boxes, three boxes, pit and decanting. According to the characteristics of the model, it can be divided into: whole mold, sand digging, false box, movable block, parting mold, car board, etc.