Resin sand casting has been widely used in the modern foundry industry due to its good casting ability and relatively simple process, and is able to produce high-quality, high-precision castings to meet the needs of different fields. For manufacturing processes, casting methods can be used to make products using molds. The material (such as metal or plastic) to make the product is poured into the mold and cooled. The mold is then pulled apart to reveal the part. The type of material used to make the mold will be based on the type of material used to make the component. Sand casting is commonly used to make parts and products using a variety of materials, as many manufacturers typically use resin sand.
What is resin sand casting?
Resin sand is a type of quartz sand mixed with a resin material. The chemical reaction produced by the resin helps to bond and harden the quartz sand, creating a strong, hard and strong mold. Resin sand can be used to make part of the mold or the entire mold material. The mold can create 3D products of various shapes, configurations and sizes. After the mold is made, the material is poured into the mold because the refractory properties of the sand help the mold remain stable. The sand is then removed through a vibration process, and then cut, ground, finished and assembled into the final product.
Pouring process
The molten metal is poured into the sand mold. During the pouring process, the pouring temperature and speed must be controlled. For different metal materials, the pouring temperature is different, such as the pouring temperature of cast iron is generally 1350-1450℃, and the pouring temperature of cast steel is 1500-1550℃. The pouring speed should be adjusted according to the structure and size of the casting to avoid the molten metal from damaging the sand mold and producing defects such as pores.
Although the mold itself is not reused because it will fall off the finished part, the resin sand can be collected and reused to make other molds in the future. Because the sand is resistant to high temperatures, a variety of metals can be used in resin sand casting. Therefore, iron, titanium and nickel alloys can be used in this process.
Function:
For manufacturers who want to use a cost-effective method to make complex parts in smaller batches, resin sand casting offers amazing advantages. One of the main advantages is that resin sand casting can produce a very smooth and strong mold surface. The reason is that the sand has the collapsibility when the mold is compressed when solidifying. Therefore, there are fewer casting defects because the molten metal can flow into every gap of the mold to produce precise dimensions.
Resin sand casting capabilities:
High casting dimensional accuracy: Resin sand has good fluidity and can accurately replicate the shape and details of the mold. The casting dimensional accuracy can reach CT7-CT9 level, and the surface roughness can reach Ra12.5-Ra25μm, reducing the workload of subsequent machining.
Wide range of applications:
It can be used to produce various types of metal castings, including cast iron, cast steel, non-ferrous metals, etc. Whether it is small and medium-sized complex parts or large simple structure castings, resin sand casting can adapt well. For example, complex castings such as automobile engine blocks and cylinder heads, as well as large machine tool beds, can be produced by resin sand casting. The process requires fewer workers to make molds and production runs, which can also save costs and pass on the benefits to customers. Because the mold is very strong, it can produce products for various purposes, such as engine blocks, cylinder heads and other engine parts, hardware, electrical contact parts, pulleys, and even landing gear parts.
High production efficiency:
Resin sand is fast in the process of sand mixing and molding, and does not require long drying processes like traditional sand molds. Generally, a resin sand molding production line can produce dozens to hundreds of boxes of castings per hour, which can meet the needs of mass production of a certain scale.
Good casting quality:
Resin sand has good disintegration and can be disintegrated in time after the casting solidifies, reducing the possibility of internal stress and deformation of the casting. At the same time, resin sand has good air permeability, which is conducive to the discharge of gas during pouring, reducing defects such as pores and sand holes, and improving the intrinsic quality of castings.
Precautions when using resin sand casting molding
One issue that needs to be considered when using this process is that it is not a fast method. The sand must be mixed and molded into parts because once the poured material solidifies in the mold, the same mold cannot be reused. Therefore, this manufacturing method is generally very suitable for complex parts or parts with high mixing and low volume.