The core of Dongguan CNC plant is made of sand and placed in the cavity to form a physical shape of the inner surface of the casting. The space between the core and the cavity surface eventually forms the casting.
The core of Dongguan numerical control processing factory is used to make the cavity and hollow protrusion which can not be produced by a single pattern. All complex shapes or cavities can be realized by cores, which makes it easy to get complex shapes. They are usually made of sand, even in metal molds. Usually, the core is filled with liquid metal, so it has to bear more severe heat transfer and mechanical conditions. Therefore, core sand should have higher strength than molding sand
(Fig. 5.26):

 As defined earlier, the gating system involves all the structures associated with the flow of liquid metal from the ladle to the cavity, including:
Sprue cup: sprue: sprue nest: runner; Runner extension; Riser; Cold iron;
In this part, we will discuss the design and function of many gating system elements. The goal of all gating system design is to get defect free castings. When designing gating system, it can be realized by making arrangements according to specific requirements.
1. The mold should be fully filled in as short a time as possible without increasing the metal temperature or using a high metal static pressure head.
2. The metal should flow into the mold smoothly without any turbulence. The turbulent metal flow is easy to form dross in the mold.
3. Undesirable materials, such as slag, dross and other model materials, should not be allowed to enter the cavity. Dongguan CNC machining plant is really good, which is worthy of attention
4. The liquid metal entering the mold cavity should be properly controlled by a method to prevent the inhalation of atmospheric gas.
5. A proper temperature gradient should be maintained so that the casting will not have any shrinkage cavity or deformation during cooling.
6. The metal shall be kept in a flow mode free from pouring corrosion or mold corrosion.
7. The casting system shall ensure that sufficient molten metal reaches the cavity.
8. The gating system shall be designed to be economical and easy to implement and to be removed after the casting has solidified.
9. Finally, the casting should be mass produced.
In order to meet the above needs, this is a very high requirement. A mold designer should strive to achieve as many goals as possible. Before the gating system structure design, let's talk about the function and classification of various gating system components.