How To Use The Jewelry Casting Equipment?
How To Use The Jewelry Casting Equipment?
In the previous article, I introduced to you the jewelry casting process and the equipment needed, so today I will introduce to you how to use the jewelry casting equipment.
1. Vulcanizer
The vulcanizer is used to make silicone molds and is used in conjunction with a wax injection machine. The jewelry samples to be produced need to be prepared in advance. A vulcanizer needs to be equipped with silicone, frame molds, and molding beads to work.
The operation steps are as follows:
- First, take out the silica gel, cut it into the appropriate size according to the size of the frame mold, and put it into the mold frame.
- Place the sample mold to be cast on the silicone and press it tightly, put a molded bead on the edge (the position reserved for the wax nozzle of the wax injection machine), and then cut a piece of silica gel to fill the mold frame completely. Repeat the above steps to fill the frame mold.
- Rotate the handle to lift the upper heating plate, place the frame mold on the lower heating plate, and then lower the upper heating plate.
- Turn on the power, rotate the temperature regulator, set the required heating temperature to start heating and vulcanization.
- After heating, take out the frame mold and cool it down.
- Take out the die bead, cut the silicone mold into two parts, modify the details, and take out the sample mold. In this way, the silicone mold is completed.
2. Wax Injection Machine
Vacuum pressure casting is also called lost wax casting. The wax here refers to the wax model, and the wax injection machine is used to make the wax model. Usually, the wax model is produced in large quantities and planted into wax trees, which can greatly improve the casting efficiency.
CDOCAST has a variety of wax injection machines, domestically produced, with imported accessories, and automated programs, which can meet the needs of different customers. The capacity of the wax injection machine is 3kg and is equipped with a 1L silent vacuum pump.
The operation steps are as follows:
- Install the clamp, connect the clamp’s air pipes, vacuum pump pipes (vacuum pump needs to be refueled before use), and compressed air pipes.
- Turn on the power, set the melting temperature, melting time, injection pressure, etc.
- Pour wax beads into the wax cylinder and start melting the wax beads. (be careful not to pour the wax beads into the vacuum chamber)
- Place the silicone mold on the fixture and align it with the wax nozzle.
- After the wax melts, start injecting wax.
3. 3D Printer
With the development of technology, many customers now choose to use 3D printing technology to make wax models. Unlike wax injection machines, making wax models through 3D printing does not require preparing sample molds in advance, but requires drawing 3D printing design drawings. The operations are as below:
1. Modeling software design:
First, users need to use specialized computer-aided design (CAD) software to create or download the required 3D model. This model will become the blueprint for the 3D printer to manufacture the object.
2. Slice processing:
The slicing software breaks down the 3D model into multiple layers of thin slices, usually dozens to hundreds, and the thickness of these slices can be adjusted according to the printer’s settings. Each layer will be printed out layer by layer by the 3D printer.
3. Printing process:
- Material selection: Select the appropriate printing material according to the requirements of the printing object. Usually, we use resin or white wax, etc.
- Print head movement: The print head moves on the printing platform according to the predetermined path, spraying, melting, solidifying, or bonding the material to the previous layer by layer until the entire object is completed.
- Bonding between layers: Each layer of material will bond with the next layer during the printing process to form a continuous structure.
4. Post-processing:
After printing is completed, some post-processing work may be required, such as cleaning, curing, surface treatment, etc., before the mold can be reversed.
The speed of 3D printing is generally slow. For printing simple objects, such as rings and earrings, about 50 can be printed in 4 hours. Larger machines can print about 200 in 4 hours. If you want to print complex styles, it usually takes more than 10 hours or even longer, so the selection of the machine is also very important.
Selection of 3D printer:
The following points should generally be considered when selecting a 3D printer:
1. Printing materials
For the jewelry casting industry, we usually use resin or white wax as printing materials, which can meet the needs of high-precision and rich-detail printing.
2. Printing size
Desktop 3D printers are usually suitable for smaller-sized printing, while industrial-grade or large-scale 3D printers are suitable for larger-sized printing objects. Some customers will cast copper or brass castings, which are very large in size. At this time, you can consider choosing an industrial-grade 3D printer.
3. Printing accuracy
Accuracy refers to the minimum layer thickness and the size of the smallest detail that the printer can achieve. For applications that require high precision, such as jewelry and model making, you need to choose a printer that can provide higher precision.
4. Printing speed
If it is used by individuals or small studios, the output is relatively small, and desktop 3D printers meet the requirements. If it is mass production or industrial-grade applications, you need to consider industrial-grade 3D printers that can withstand long-term operation and mass production requirements.
5. Budget
Budget is an important consideration. The price of 3D printers of different types and specifications varies greatly. For example, LCD printers and DLP printers use different technologies, so there will be a certain gap in price. The price of desktop printers and industrial-grade printers can differ by several times. The price is also affected by the different functions of the machine, such as automatic liquid addition, automatic pickup, visual inspection, etc.
Therefore, considering the above factors, you can choose to use a combination of vulcanizer + wax injection machine, or choose to use a 3D printer to make wax molds.
4. Vacuum Gypsum Mixer
After the wax model is completed, the next step is to prepare the plaster model. The production of the plaster model requires the use of a vacuum powder mixer, which is used to mix the plaster and water into a slurry while evacuating the vacuum and then injecting it into the steel cup. Depending on the different metals being cast, we usually use different powders.
The operation steps are as follows:
- Connect the power cable. Connect the vacuum pump and check whether the rotation direction of the vacuum pump motor is correct. (the direction indicated by the arrow is the rotation direction of the motor)
- Mix the powder and water in a certain proportion to make a slurry and pour it into the mixing cylinder
- Turn on the stirring, then turn on the vacuum pump, and remove the air in the slurry while stirring
- After the stirring is completed, open the lower tank to vacuum, and after the bottom is pumped, open the upper and lower cylinder connection valves and inject the slurry into the steel cup (during the whole process, the vacuum pump needs to be turned on until there are no bubbles on the surface of the steel cup)
- Then take out the steel cup, put it aside to dry, and wait for burning.
- After the stirring is completed, use a water gun to clean the remaining gypsum to prevent the gypsum from hardening on the machine
5. Vibration Vacuum Machine
The vibration vacuum machine is used to evacuate the plaster mold. If the plaster mold has been made with a vacuum mixer, the vibration vacuum machine is not needed. If the mixing step is not carried out in a vacuum environment, vacuuming is performed at the end after the mixing is completed to prevent bubbles from forming in the casting.
The vibration vacuum machine also needs to be connected to a vacuum pump to work. We generally have a 15L vacuum pump. The operation is very easy:
- Connect the power supply and vacuum pump.
- Place the steel cup on the platform and cover it with a hood.
- Turn on the vacuum switch to start vacuuming, turn on the vibration switch, and the motor under the platform will start to vibrate so that the slurry can expel bubbles and mix more evenly.
- Turn off the vacuum switch and turn on the exhaust switch to exhaust.
- Finally, open the hood, take out the flask, put it aside to dry, and clean the platform.
6. Burnout furnace
After the plaster mold is dried, it needs to be placed in an oven to dry and dewax, so this casting method is also called lost wax casting. The oven is generally composed of a heating chamber, a temperature control meter, a wax barrel, and other parts. According to the different heating methods, it can be divided into ordinary heating and segment heating.
When you purchase an oven, please be sure to specify the size of the heating chamber, or tell the supplier the size of the flask and how many pieces of flask need to be put at a time, we can customize it according to customer needs.
The temperature control meter can choose to use ordinary heating or segment heating. Our segment heating meter has 32 programs, which can be used for 32-segmented heating. Set the required temperature and heating time for each segment directly on the temperature control meter, and the oven will work automatically.
In addition, it is optional whether to have secondary combustion. Secondary combustion is used to burn the residual wax completely. If many plaster molds need to be baked each time, it is recommended to choose secondary combustion.
In addition, we also have rotary burnout furnaces, that is, add a turntable in the heating chamber, which rotates while heating, so that the plaster mold can be heated more evenly.
The operation of the burnout oven is very simple
1. Connect the power cable.
2. Put in the plaster molds, turn on the power, set the heating time and heating temperature, and start heating (generally, the supplier of plaster powder will provide the heating curve required for plaster powder, and the temperature and time can be set according to the heating curve)
3. During the heating process, the wax will flow into the wax barrel from the bottom. After the heating is completed, take out the plaster mold.
The above is the preparation work for jewelry casting. In the next article, I will introduce the operation of other jewelry casting equipment.
Learn more about the jewelry casting