5 main stages in the casting process

The process of manufacturing pressure molds includes 5 main stages: clamping, spraying, cooling, dismantling, and cutting. Total time of the whole process up to 4 minutes, each stage is from 2s to 1 minute.

Stage 1: Clamp

The first stage is to prepare and clamp two halves of the mold. Each half of the mold is first cleaned from the previous spray line and then lubricated to facilitate subsequent removal of the product. Lubrication time depends on the size of the product as well as the number of cavities and side cores. Every 2 to 3 cycles, people lubricate once and also depend on each material. After lubrication, the two halves are attached to the inside of the casting machine and are tightly clamped and closed together. People use a sufficient force to close the mold during the metal injection process. The time it takes to close and clamp the mold also depends on the type of machine (a large-sized machine) that uses more force and needs more time. The time can be calculated from the drying time of the machine.

Stage 2: Spray

The molten metal is maintained at a fixed temperature in the furnace, followed by a transition to a chamber here, it can be sprayed and molds. The method of transporting flowing metal also depends on the type of casting machine, whether the type of hot chamber machine or cold chamber is used. Once transported, the molten metal is sprayed with high pressure into the mold. Typical pressure can reach 1000-20000 psi. This pressure holds the metal in the mold during its solidification. The injection time is the time from the melting of the molten metal into the channels of the cavity molds. This time is very short, less than 0.1s, to prevent premature solidification in any part of the product. The exact injection time can be determined by the thermodynamic characteristics of the material, the thickness of the wall of the casting product. The greater the thickness of the wall, the longer it requires the spray chamber, where it uses cool injection chamber pressure molding machine, the spraying time must include the time to control the molten metal tray into the storage chamber.

Stage 3: Cooling

The molten metal sprayed into the mold will start cooling and solidifying when it enters the mold cavity. When the entire mold cavity is filled and the molten metal will solidify, the final shape of the molded product will be formed. The mold will not open until the cooling time is low and the final product is solid. Time can be calculated thanks to the thermodynamic properties of the metal, maximum product wall thickness and mold complexity. The larger the thickness of the wall, the longer it will need to cool. The complexity of the geometric shape also requires a longer cooling time because of more barriers to heat flow

Stage 4: Removing / withdrawing

After the cooling time has elapsed, the two halves can be opened, and the propulsion mechanism is used to push the molded product out of the cavity. The time used to open the mold can be calculated by the drying cycle of the machine and the time of removal determined by the mold casing and should include the time when the casting product falls freely from the mold. One must use more force in the propulsion mechanism to remove the product because during cooling, the product shrinks and sticks to the mold. When the product is removed, the mold is clamped in again to be used for the next injection.

Stage 5: Cut

During cooling, the material on the groove of the mold will solidify and attach to the end product. These surplus parts and many types of ash will appear and must be removed by cutting or sawing or using the pressing method. The time required to trim the excess can be calculated thanks to the size of the mold cover. The scrap from the cutting process will be collected or can be reused in the next pressure casting process. Recyclable materials can be recovered to create a reasonable chemical compound before being combined with non-recyclable materials and reused in the next casting pressure.

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QUANG TRUNG INDUSTRIAL GROUP JOINT STOCK COMPANY

- Address of representative office at: Lot 33, Villa 4, Linh Dam Peninsula, Hoang Mai, Hanoi

- Phone: 0379645086

- Email: tapdoanquangtrunggroup@gmail.com