YIDE CASTING has a high advanced sand module making machine line imported Germany, automatic sand casting enhances our production efficiency. In addition, the automatic sand modules are also firmer than the manual sand module, which help YIDE CASTING a lot in manufacturing top quality casting iron part.
Green sand casting is also named clay sand casting.
Yide casting makes sand module by the way of clay sand casting, and these sand can be reused for many times. And Yide Casting always takes use of this sanding module making way for iron casting, or some casting products which can accept rough surface.
Shell sand casting is a precoated casting, which makes use of disposable sand for sand molding, can melt the pig iron as smooth casting product in the pouring step. Of course, the cost is more expensive than green sand casting, so this shelling iron casting is always used for some casting iron accessories which have smooth surface requirements.
Sand Casting Process
YIDE CASTING provides module design service too, then manufacturing an iron cast sample in 60 days.
YIDE CASTING provide OEM service.
R & D ABILITY
Yide Casting has our patented product – JM heat exchanger.
Yide Casting is equipped with test machine – spectrum analyzer, three-coordinate detector, metallographic analyzer, and tensile testing machine imported from Germany
A customized package is available, wood carton in general.
Order information tracking is available in 3 years, you can contact us at any time if problem.
We are great at what we do
Yide Casting has competed producing and quality control management system, has a strict quality requirement by ourself, and Yide casting is also equipped with many testing machines for our steel cast, iron casting products.
20000 TONS PRODUTION
OEM CASTING SERVICE
JM HEAT EXCHANGER (patent)
Sand casting – what is sand casting
Sand casting is a casting method in which use casting sand and core sand as modeling materials, and fill castle casting model with liquid metal under gravity to produce castings.
Steel, iron and most non-ferrous alloy castings can be obtained by sand casting. The molding materials used in sand casting are cheap and easy to obtain, the casting mold is easy to manufacture, and can adapt to single-piece production, batch production and mass production of castings.
green sand casting castle cast
Thus it has been the basic process in casting production for a long time. The castle casting used in sand casting is generally composed of sand mold and sand core. In order to improve the surface quality of castings, a layer of paint is often applied on the surface of sand mold and sand core. The main components of the coating are powdery materials and binders with high refractoriness and good chemical stability at high temperatures. In addition, a carrier (water or other solvents) and various additives for easy applications are added.
How To Control The Moisture of Used Sand of Green Sand Casting
It is a common thing to control the moisture of content of mixed sand for all of casting foundries, but many foundry leaders and technicians still lack sufficient understanding of the importance of strictly controlling the moisture content of used sand.
If the moisture content of the used sand entering the mixed sand is too low, the final casting product will have a quality problem, which even more serious than too high sand temperature.
According to the research and experience of sand casting, wetting dry bentonite with water is much more difficult than lubricating wet bentonite. The bentonite and water in the molding sand are not simply mixed together, but must be kneaded to make them plastic.
This is like making pottery with water and clay. The water and clay are combined into one, which is loose and has no bonding ability; after rubbing and beating, each grain of soil fully absorbs moisture and becomes a plastic state, and be shaped to make pottery blanks.
After casting, due to the influence of the hot metal, the soil-water bonding film on the surface of sand is dehydrated and dried. It is not easy to restore the plasticity by adding water. The lower the moisture of the used sand, the longer it takes to add water to achieve the required performance. Since the time for mixing sand in production is limited, the lower the moisture of the used sand, the worse the overall quality of the mixed sand.
Currently, foundry workers in all countries have reached a consensus, that the water content of the used sand entering the sand mixer can only be slightly lower than that of the mixed sand.
Preferably, fully adding water in the cooling process of the used sand can make sure that the water content after cooling is slightly lower than the mixed sand. In this way, there is a considerable period of time from the cooling process to the entering into the mixer, thus water can fully wet the bentonite on the surface of the used sand.
Better yet, set up a sand mixer in the system to pre-mix the used sand. The cooled used sand is pre-mixed with water in the pre-mixed sand mixer to improve the mixing state of bentonite and water in the used sand. Some foundries will add all the additional materials such as new sand, bentonite and coal powder when pre-mixing.
Yide Casting premixed with a sand mixer made in Germany. After the pre-mixed used sand, the amount of water added after entering the sand mixer is very small, but it is only slightly adjusted. The bentonite and water in the molding sand are further prepared in the sand mixer, and the performance of the molding sand is more stable and consistent.
Different Types of Foundry Sand
In the 17th century, China had used silica sand as a molding material to make castings such as bells, mirrors, pots and artillery. However, the early used mostly natural clay-containing silica sand, namely mountain sand and river sand. The natural sand has good plasticity and can be directly used to make molds and cores, which is suitable for the conditions of manual production at that time.
After entering the industrialized large-scale production, especially the modeling mechanization, the natural clay-containing silica sand showed several problems.
①Poor performance uniformity;
② The quality of the molding sand is difficult to control;
③ It cannot meet the process requirements.
Therefore, the natural silica sand with low mud content and artificial silica sand made by crushing silica were adopted. At the same time, the use of various non-siliceous sands has also been expanded.
The application and development of resin sand modeling and core making technology puts forward higher requirements on the quality of foundry sand, such as less fine powder, small specific surface area, and low acid consumption. In addition, there are new requirements for the size, shape and particle size distribution of sand particles. Some countries lacking high-quality sand sources have also developed silica sand washing technology to improve the grade and quality of silica sand.
Foundry sand should meet the following requirements:
1. Higher purity and cleanliness. Taking silica sand as an example, the content of SiO2 for cast iron sand should be more than 90%. And for larger steel castings, the content of SiO2 should be more than 97%.
2. High Refractoriness and thermal stability.
3. Suitable particle shape and particle composition.
4. Not easily wetted by liquid metal.
5. Cheap and easy to obtain.
The particle shape and particle composition of foundry sand have an impact on the fluidity, compactness, air permeability, strength and resistance of liquid metal permeability of the sand. Both the partible shape and composition are important indicators of the quality of foundry sand.
There are generally three types of particle shapes of foundry sand.
1. Round sand: The particles are round or close to round, with smooth surface and no prominent edges and corners.
2. Polygonal sand: The particles are polygonal, and most of them have obtuse angles.
3. Sharp-angled sand: The particles are sharp-angled, and most of them are acute.
generally, the angle coefficient (the actual specific surface area of the sand/theoretical specific surface area of the sand) decide the particle shape of foundry sand.
The sieve number determine the particle composition of sand. The measurement method is to pour the dry water-washed sand to remove the mud and dry it into a standard sieve, and then put it on the sand sieve for sieving. After separation, weigh the sand remaining on each sieve separately. Usually, the first and last sieve numbers of the three adjacent sieves with the most concentrated sand after sieving with a standard sieve represent the particle composition.
According to the different mineral composition, foundry sand consist of two categories: silica sand and non-siliceous sand.
Silica sand of whose main mineral composition is SiO2.
1. Natural silica sand: used for molding sand and core sand for non-ferrous alloy, iron and medium or small steel castings.
2. Selected natural silica sand: used for all kinds of molding sand and core sand using organic matter as a binder.
3. Artificial silica sand: molding sand and core sand for steel castings.
Non-siliceous sand: there are many types of non-siliceous sand, with different uses.
1. Limestone sand: Made of crushed limestone, the main mineral composition is CaCO3. Mainly used for molding sand and core sand of steel castings.
2. Zircon sand: The main mineral composition is ZrO2·SiO2. Mainly used for the core sand or surface sand of large steel castings and alloy steel parts. Its powder can be used as a coating.
3. Magnesia sand: The main mineral composition is MgO. Mainly used for the surface sand and core sand of high manganese steel castings. Its powder can be used as a coating.
4. Chromite sand: The main mineral composition is FeO·Cr2O3. Mainly used for the surface sand and core sand of large or special steel castings. Its powder can be used as a coating.
5. Corundum sand: The main mineral composition is α-Al2O3. Mainly used as a shell material for investment and ceramic mold casting.
6. Olivine sand: The main mineral composition is (MgFe)2SiO4. Mainly used for molding sand and core sand for iron castings, non-ferrous alloy castings and high manganese steel castings.
Yide Casting is a professional casting & machining factory in China, specialized in green sand casting and clay sand casting. Otherwise, Yide casting has our patent JM heat exchanger for air conditioner…Read more.