How to make gold silver jewelry?-Vacuum pressure lost wax jewelry casting machine
Vacuum pressure lost wax jewelry casting machine
As a limited resource, gold has a strong value-preserving function. Processing gold into jewelry through design, carving, and other processes can not only give it beauty, but also increase the value of gold, so it has become the choice of many gold suppliers.
Do you know the method of jewelry casting? Do you know what equipment is needed for jewelry casting? in the following article, I will introduce jewelry vacuum pressure casting and the equipment needed.
What is Jewelry Vacuum Pressure Casting?
Vacuum pressure casting is an advanced metal casting process that combines vacuum technology and pressure control technology to produce high-quality, pore-free and inclusion-free metal castings. In vacuum pressure casting, a vacuum environment is created in the casting chamber and appropriate gas pressure is applied before the metal material is melted and injected into the mold.
Compared with traditional casting processes, Vacuum pressure lost wax jewelry casting machine has the following advantages:
- Reduce pores and inclusions: Through vacuum extraction, the air in the chamber can be effectively removed, the pores in the casting can be reduced, and the quality of the casting can be improved.
- Improve density and strength: Applying pressure can increase the density and uniformity of metal filling, improve the strength and sealing of the casting.
- Improve surface quality: In a vacuum environment, the introduction of protective gas reduces the oxidation reaction and can obtain a smoother and defect-free casting surface.
- Precisely control the casting process: With the help of an intelligent control system, parameters such as temperature, pressure and time can be precisely controlled to improve production efficiency.
Vacuum pressure casting process:
Step1. Make the wax tree
Cut the silicone into appropriate sizes, divide it into two layers, clamp the sample mold, and fit them into the frame mold. Place the frame mold on the heating plate of the vulcanizer for heating and vulcanization, put the vulcanized silicone into the water to cool and cut, take out the sample mold, and the complete silicone mold is made.
Pour the wax beads into the wax cylinder of the wax injection machine and heat them. Place the silicone mold in the clamp and align it with the wax injection mouth to inject wax. After cooling, take out the wax mold. You can weld the wax mold to the wax column to build a wax tree for batch production, which greatly improves casting efficiency. After the wax tree is made, put it into the flask and wrap it with tape. Note that the tape should be about 3-4 cm higher than the flask, which can effectively prevent gypsum from splashing out in the following operations.
However, many customers choose to make wax molds through 3D printing. They prepare the design drawings of the jewelry, put the wax or resin into the 3D printer, and the printer will print out the wax mold according to the drawings. It is very suitable for jewelry with complex designs. At the same time, it can print a large number of wax molds at one time, which has a high production efficiency.
Step2. Make the gypsum mold
Add the gypsum powder and water to the vacuum mixer according to the required proportion and stir them. While stirring, the vacuum pump will evacuate the gypsum liquid. Pour the stirred gypsum liquid into the flask. The poured gypsum liquid should completely cover the wax mold, and it is best to leave a distance from the top of the flask. Then place the flask on the vibration vacuum machine and evacuate the gypsum mold while vibrating. This can effectively reduce burrs and pores and improve the quality of the casting. The finished gypsum mold needs to be placed in a cool place to dry and shape.
Step3. Burning and dewaxing
Put the gypsum mold in the burnout furnace, set the heating time and temperature according to the needs, start burning and dewaxing. The wax will flow into the wax collection bucket below. If you dewaxing a large batch of molds at one time, it is recommended to choose a burnout furnace with secondary combustion which can fully burned the wax to minimize the wax smell in the environment. After the dewaxing is completed, the preliminary preparations are all completed, and then you can start casting.
Step 4. Melting and casting
Prepare the metal material, put the gypsum mold into the casting chamber, then put the metal material into the melting chamber, set the working parameters, and start the machine. CDOCAST’s Vacuum pressure lost wax jewelry casting machine is equipped with a Siemens touch screen and PLC control. You only need to set the working parameters, and the machine will automatically start melting, vacuuming, pressurizing, adding protective gas, and casting. All casting data can be stored and adjusted.
After the casting is completed, take out the casting mold, put it in a bucket to clean up the gypsum, and you will get a semi-finished casting.
Step5. Cleaning
The semi-finished castings are covered with a lot of plaster which is difficult to clean. They need to be cleaned by spraying water from a plaster cleaning machine. The cleaned castings can then be cleaned with a sandblasting machine to remove tiny surface oxides.
Step6. Polishing
The cleaned castings need to be polished to make them brighter. There are many choices for polishing machines. First, you can use a magnetic polisher to remove the burrs on the jewelry, and then use a vibration polisher to polish the jewelry. The vibration polisher needs to be used with polishing liquid and polishing beads. Common polishing beads include steel beads, zirconium oxide, high-aluminum porcelain, corundum, and other materials. Choose according to the budget and the desired effect.
You can also choose to use a double-barrel eddy current polisher, one barrel for grinding and deburring, and the other barrel for polishing. One machine solves all problems.
The above is all the processes of vacuum pressure casting, which can be used for casting gold, silver, copper, and alloys. In the next article, I will explain how to cast high-melting point metals such as platinum, palladium, stainless steel, etc.