Casting sand with common sense
Tidal mold sand, clay sand, water glass, coated sand, resin sand are cast in the sand casting, but the difference between the different binders.
Tidal mold sand, clay sand, wet sand is the same, the binder is an ordinary clay or bentonite, as in the process of mixing sand to add water, so called Chao mold sand.
Water glass sand binder is sodium water glass, usually by blowing carbon dioxide hardening or hardening agent from hardening. Coated sand binder is generally phenolic resin, micro-toxic, generally used for sand core.
Resin sand binder for the furan resin, resin sand molding in the pouring gas after relatively large. At present, the quality of casting sand molding resin sand casting is the best.
Water glass sand is used to make a shell of a material, but also can do binder, not an independent casting method
There are two main ways to use:
1, quartz sand + water glass (to do with the binder) sand type, access to carbon dioxide fast curing
2, lost wax casting shell process, adding water glass to do binder
Water glass is very soft wax, silica sol wax is very hard. Silica sol product surface is better than water glass. The two are only in the quality of manufacturing-off customers are different, silica sol manufacturing out of the type is more suitable for precision casting, manufactured products surface smoothness, deformation, shrinkage ratio is small, and the size of precision does not require secondary processing.
But the silica sol to do the basic are small products, water glass EPC products are relatively large. The two are only in the quality of manufacturing-off customers are different, silica sol manufacturing out of the type is more suitable for precision casting, manufactured products surface smoothness, deformation, shrinkage ratio is small, and the size of precision does not require secondary processing. Water glass is very soft wax, silica sol wax is very hard. Silica sol product surface is better than water glass. Principle is the same with the two wax, sand surface, the adhesive is not the same
The quality of the product is significantly different. Abroad are basically silica sol technology, water glass technology should be more domestic. There are water glass sand is too much trouble, because the water glass will sinter in the casting surface
Sodium silicate solution commonly known as water glass, also known as sodium silicate, water glass sand with a low price, high strength, non-toxic, etc., in the casting production is widely used, but because of its collapsibility is poor, it can not completely replace the other sticky Knot. There are many measures to improve the collapsibility of sodium silicate sand, but all can not achieve satisfactory results. Carbon dioxide water glass sand as a result of high modeling efficiency, casting without baking that can be poured, and other characteristics, and thus in the cast steel and some cast iron production to be more widely used. But for a long time, this kind of sand has the two big problems of collapsibility and old sand regeneration troubles, which greatly limits its wider application. In recent years, with the progress of technology, the emergence of water glass modification and improve the collapsibility of additives and other methods, so that the problem of poor collapsibility is gradually resolved; old sand regeneration problems also appeared in a number of solutions, the author of wet regeneration technology, Low investment, high recovery rate, environmental protection, low cost to solve this problem. Features: simple equipment, less investment, high recycling rate, environmental protection, and low cost.
1: simple equipment: simple magnetic separation, crushing, mixing washing machine, water tank, sewage tank, sewage treatment tank each one, two pumps.
2: less investment: an annual output of 1,000 tons casting plant, only a few million investment.
3: high recovery rate: the old sand regeneration recovery is greater than 90%.
4: environmental protection is good: washing sand after the use of recycled water to achieve zero discharge of waste water. The old sand regeneration process for wet operation, the environment is basically no dust. 5: low cost: per ton of sand recycling cost less than 30 yuan .
