What You Need To Know About Jewelry Casting_ From Material Preparation To Advanced Techniques.pptx

Hey jewelry fans! Ever wondered how those sparkly pieces go from raw metal to stunning jewelry? Let's break it down in a fun and easy way!
First, we start with material prep. Think of it like baking: you need the right ingredients. We use 18K gold, recycled metals, and even cool stuff like brass and silver. We clean the recycled bits, break them into smaller pieces, and mix them with new metals. Then, we label everything so we know what’s what.
Next, it’s time to cast! There are a few cool methods:
Vacuum Casting: We melt brass in an induction furnace and pour it into a mold using a vacuum machine. It’s like filling a cup without spilling!
Vacuum Pressure Casting: This is like using a super-powered vacuum to push molten silver into a mold. It’s super precise!
Vacuum Centrifugal Casting: Imagine spinning a cup of liquid really fast to fill a mold. This method is perfect for platinum jewelry.
Vacuum Continuous Casting: This is like making a long, continuous piece of gold. It’s great for making bars.
Each method uses cool tools like crucibles, flasks, and even quartz molds. We also check everything with machines to make sure the jewelry is perfect.
Whether you’re a jewelry store, designer, or even a celebrity looking for custom pieces, this process makes sure every piece is top-notch. Ready to create some magic? Let’s get casting!

1. What You Need To Know About Jewelry Casting: From Material Preparation To Advanced Techniques Get entire article, please visit: https://sobling.jewelry/what-you-need-to-know-about-jewelry-casting-from-material-preparation-to-advanced-techniques/

2. CONTENTS 01 Material Preparation 02 Vacuum Casting 05 Vacuum Continuous Casting 04 Vacuum Centrifugal Casting 03 Vacuum Pressure Casting

3. 01 Material Preparation

4. Background Knowledge Composition of Charging Materials: In jewelry production, waste materials are recycled to reduce new material usage, but they must be cleaned and categorized to avoid quality issues, with recycled material proportions often exceeding 50% despite potential risks to alloy properties. Density Density, a key material characteristic, varies with composition and structure, helps identify material types, and is used in jewelry production to calculate material requirements and detect internal defects. Reusable Waste Materials in Jewelry Production

5. Task Implementation - U se 18K rose gold pre-melt and recycled materials to achieve a fineness of 18K and a rose red color  Cleaning the metal model tree core with a sandblasting machine 1 Cleaning of Recycled Materials Inspect and clean recycled materials, removing contaminants using tools like magnetic tumblers or sandblasting machines. 2 Pre-alloying of New Materials Prepare new materials, such as 18K gold, following internal control standards. 3 Charging Material Decomposition Break down oversized materials into smaller pieces for precise mixing and melting. 4 Mixing Calculate and mix materials based on wax model weight and density, ensuring a 6:4 ratio of new to recycled materials. 5 Labeling Label prepared materials with type, quality, and flask number for identification. 6 End of Work Submit materials, turn off equipment, and clean the workspace after batching.

6. 02 Vacuum Casting

7. Background Knowledge

8. Background Knowledge Vacuum suction casting machine Stainless steel flask Graphite packing Steel flask clamp

9. Task Implementation - U se an induction furnace to melt brass charge, pour the molten metal into a gypsum mold, and fill it using a vacuum casting machine  Product structure to be poured Melting pre-melted materials Placing the gypsum casting mold Pouring molten metal Verify material and product structure, set pouring temperature to 1010℃, and ensure charge cleanliness. Prepare melting crucible, check vacuum casting machine, and ensure proper vacuum levels. Add brass materials to crucible, heat gradually, and protect molten metal with charcoal to reduce oxidation. 4.Place gypsum casting mold into vacuum casting machine and check sealing performance. 5.Pour molten metal steadily into mold, controlling speed to avoid overflow. 6.After pouring, vacuum until metal solidifies, then remove casting mold for cooling. 7.Clean equipment and work area after completing all casting molds.

10. 03 Vacuum Pressure Casting

11. Background Knowledge Section Content Details Casting Performance Key Factors Filling ability, shrinkage, segregation, and gas absorption affect casting quality and defect formation. Casting Process Methods and Quality Control Traditional manual methods lead to quality fluctuations; automatic casting machines (e.g., induction melting vacuum pressure casting machines) improve consistency. Vacuum Pressure Casting Machine Structure and Operation Upright structure with melting chamber, casting chamber, and lifting cylinder; uses consumable parts like graphite crucibles and quartz shells; controlled via an interface with program library, temperature control, and process parameters.

12. Background Knowledge  Induction Melting Vacuum Pressure Casting Machine Common consumable parts of vacuum pressure casting machines Example of the control interface of the vacuum pressure casting machine

13. Task Implementation - Adding charging materials to the crucible Heating and melting Placing the casting mold Automatic pouring and pressurization Verify material, product structure, and set pouring temperature to 980℃ before melting. Prepare equipment, ensure cleanliness, and select the 925 silver casting program. Add 925 silver materials to the crucible, avoid overpacking, and initiate automated heating. 4.Place the casting mold correctly using the steel flask clamp and ensure proper alignment. 5.Automatically pour molten metal into the mold under vacuum and pressure for solidification. 6.Remove the casting mold after pressurization and cooling, and place it in the designated area. 7.Cool the furnace, clean the workspace, and ensure equipment is shut down properly after casting. U se a vacuum pressure casting machine to melt and cast 925 silver jewelry

14. 04 Vacuum Centrifugal Casting

15. Background Knowledge Fast filling speed suitable for fine structures or high melting point materials. Modern machines integrate vacuum protection, automatic control, and functional improvements. Various configurations include vertical/horizontal crucibles and molds, with synchronous centrifugal pouring widely used for platinum jewelry. Vacuum Centrifugal Casting Machine Material Requirements: Crucibles must have high refractoriness, thermal shock resistance, chemical inertness, and mechanical strength. Graphite crucibles are preferred for gold, silver, and copper, while ceramic crucibles (e.g., quartz) are used for platinum and palladium due to carbon poisoning issues. Usage and Degradation: Quartz crucibles are used for high melting point materials like platinum despite their lower melting point. With repeated use, a transparent glass layer forms on the inner wall, increasing thickness and reducing surface smoothness. Bubbles form due to the interaction of melting temperature, crucible structure, and liquid metal pressure, leading to eventual fragility and failure. Crucibles for Centrifugal Casting

16. Background Knowledge  Appearance of the vacuum centrifugal casting machine Variable arm of the vacuum centrifugal casting machine Vertical crucible kit for centrifugal casting Quartz Crucible for Platinum Melting

17. Background Knowledge Condition of quartz crucible interior and outlet after melting Pt950 platinum four times (7x magnification) Transparent glass layer and bubble zone on the inner wall of the quartz crucible (7x magnification) Bubble morphology on the inner wall of the crucible

18. Task Implementation - Use vacuum centrifugal casting machine to melt and pour Pt950 jewelry Verify material and product structure, ensuring cleanliness and setting the pouring temperature to 1900℃. Prepare for melting and pouring by setting the mold angle, cleaning the crucible, and checking equipment functionality. Melt charging materials in the crucible, ensuring they are not packed tightly and stirring for uniform composition. 4.Place the casting mold correctly on the mold support and prepare for vacuum extraction. Adding charge to the crucible Stirring the molten metal Placing the casting mold 5.Perform vacuum centrifugal casting once the molten metal reaches the stable pouring temperature. 6.Remove the casting mold after the rotation stops and the vacuum is broken, then cool it in a designated position. 7.Conclude work by cleaning and maintaining the equipment and workspace. Vacuum centrifugal casting Removing the mold after pouring

19. 05 Vacuum Continuous Casting

20. Background Knowledge Principle of Continuous Casting Vacuum Continuous Casting of Jewelry Profiles Bottom-Drawing Continuous Casting: Molten metal is pulled downward by gravity in a closed furnace, enhancing density and reducing voids, commonly used for gold, silver, and copper profiles. Top-Drawing Continuous Casting: Metal is drawn upward under vacuum, suitable for producing strips, bars, and pipes with high efficiency but prone to central looseness. Horizontal Continuous Casting: Metal flows horizontally into a crystallizer, offering simpler equipment and higher efficiency but limited to small-sized profiles due to uneven cooling. Vacuum continuous casting ensures high-quality, oxidation-free jewelry profiles by integrating induction melting, electromagnetic stirring, and vacuum protection, with precise temperature and drawing control for uniform composition and surface quality.

21. Background Knowledge Schematic diagram of bottom-pulling continuous casting Schematic diagram of top-pulling continuous casting Principle diagram of horizontal continuous casting Vacuum continuous casting machine for jewelry materials Melting crucible and forming mold

22. Task Implementation - U se a bottom-drawing vacuum continuous casting machine to produce 18K rose gold bars Adjusting the directional pulley to fit the straight traction rod Combining the graphite crucible and the crystallizer through threads Schematic diagram of the melting chamber assembly  Adding Charge Bar Materials of Continuous Casting Preparation Work : Inspect and clean the graphite crucible, crystallizer, and pulling rod, ensuring proper assembly and applying graphite slurry for smooth casting. 3.Melting Charge Material : Evenly distribute the charge in the crucible, melt under vacuum and argon, and use electromagnetic stirring for uniform composition and temperature. 2.Melting System Assembly : Assemble the crucible-mold unit, install the graphite plug rod, thermocouple, and pulling rod, and adjust the directional pulley for straight traction. 4.Traction Casting : Stabilize molten metal temperature, lift the plug rod, and start traction to solidify and continuously cast the metal. 5.Cutting and Removing Profile Materials : Cut the cast bar at ~500 mm, remove remaining profiles, and detach the bar from the pulling rod. 6.End of Work : Cool the furnace, clean the melting chamber, and tidy the workspace after casting.

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