Vacuum Casting Services
Ultirapid’s Vacuum Casting Services offer high-quality manufacturing for low to medium volume parts at competitive prices. From mold creation to part production, our streamlined process ensures precision and efficiency. Typically, we complete both mold manufacturing and part production within 10-15 days, providing you with reliable, cost-effective solutions for your prototyping and production needs.
- Quick Turnaround And Delivery
- Wide Range Of Materials Available
- 24/7 Technical Support
Fast Delivery
3-5 Days
Low MOQ
20-50 Pcs
DFM
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What Is Vacuum Casting?
Vacuum casting is a manufacturing process used to produce high-quality prototypes and low- to medium-volume parts. It involves creating silicone molds from a master model, typically made through 3D printing or CNC machining. Liquid resin is then poured into the mold under vacuum conditions to ensure precision and reduce air bubbles. This process is ideal for replicating complex geometries, delivering parts with excellent surface finish and detail. Vacuum casting is popular in industries like automotive, medical devices, and consumer goods.
Vacuum Casting Process
Step 1
Master Model Creation
The process starts by creating a master model of the part, often using 3D printing, CNC machining, or other methods. This master serves as the template for the silicone mold used in vacuum casting, ensuring precise replication.
Step 2
Mold Creation
To create the mold, apply layers of flexible silicone over the master model. After curing, carefully split the mold to extract the master, leaving a cavity that precisely replicates the part’s shape for accurate casting.
Step 3
Mixing and Degassing
Prepare the resin or silicone material by mixing a two-part resin thoroughly in a container. This mixture, essential for creating high-quality castings, should be well combined to ensure consistent results and optimal performance in the final part.
Step 4
Casting
Pour degassed resin into the silicone mold, ensuring it fills every detail. Place the mold in a vacuum chamber to remove air, allowing the resin to flow thoroughly and capture the intricate features of the mold.
Step 5
Cure The Resin
Cure the resin by placing the filled mold in an oven or at room temperature. This process solidifies the resin into the final part, with curing times varying from hours to days, depending on the material and temperature conditions.
Step 6
Part Demolding
After curing, carefully open the mold to extract the finished part. Depending on your needs, you may need to clean, trim, sand, or apply a finish to achieve the desired final appearance and functionality.
Step 7
Post-Processing
After casting, perform post-processing tasks like trimming, sanding, and finishing. Additional steps may include painting or assembling to refine the part and meet specific application requirements, ensuring the final product achieves the desired quality and appearance.
Step 8
Quality Control
Conduct quality control by inspecting the finished part for accuracy and defects. Check dimensions, surface finish, and functionality against specifications to ensure it meets required standards. Any inconsistencies should be addressed through corrective measures before final use.
Vacuum Casting Tolerances
Ultirapid adheres to ISO 2768 Coarse (C) standards for urethane casting, ensuring reliable precision. For unspecified features, standard tolerances apply. While tighter tolerances can be achieved, they are recommended only for critical features to maintain cost-effectiveness and production efficiency.
| Tolerance Category | Tolerance Description | Typical Tolerance Range | Ultirapid Tolerance Range |
|---|---|---|---|
| Linear Tolerances | Tolerances for linear dimensions such as length, width, and height | ±0.1 mm to ±0.5 mm (depending on size and complexity) | +/- 0.3mm |
| Angular Tolerances | Tolerances for angles between surfaces | ±1° to ±3° | +/- 1 ° |
| Surface Tolerances | Tolerances for surface finishes, including smoothness and flatness | Ra 0.8 to 1.6 µm (surface roughness) | 1.6 ~ 12.5 microns Ra |
| Shrink Mitigation | Compensation for material shrinkage during cooling and solidification | Typically accounted for in design phase | 0.15% |
| Holes | Tolerances for hole diameters and locations | ±0.05 mm to ±0.2 mm (depending on hole size) | Up to .250” diameter +/- .003” Up to .500” diameter +/- .004” Over .500” diameter +/- .0005” per inch |
Vacuum Casting Materials
Silicone
Silicone is renowned for its exceptional flexibility and outstanding resistance to extreme temperatures. Its unique properties make it ideal for producing components with intricate geometries and high precision. This material is particularly favored in the aerospace industry, where reliable performance under demanding conditions is crucial, as well as in medical devices and high-performance automotive applications.
Common Applications: Silicone is ideal for aerospace components requiring flexibility, precision, and temperature resistance. It’s also used in medical devices, automotive seals, and consumer products like kitchenware, due to its durability and non-reactive properties.
Polythene (PU)
Polyurethane (PU) is a versatile material that offers ease of processing and the ability to produce complex shapes with remarkable precision and accuracy. Its cost-effectiveness and efficiency in mass production make it a popular choice for a wide range of applications, including automotive components, consumer goods, and industrial parts where durability and performance are key.
Common Applications: PU is excellent for mass-producing complex, precise shapes in automotive parts, consumer goods, and industrial components. Its durability and cost-effectiveness make it suitable for medical devices and various industrial applications requiring high wear resistance.
Epoxy
Epoxy is a thermosetting resin known for its exceptional strength and resistance to chemicals and heat. It is widely used in industries such as automotive, aerospace, and marine, where the durability of high-strength parts is essential. Additionally, epoxy is a critical material in electronics for protective coatings and in construction for structural bonding and repairs.
Common Applications: Epoxy is used in automotive, aerospace, and marine industries for high-strength, heat-resistant parts. It’s also vital in electronics for protection and construction for structural bonding and repairs.
Polyvinyl Chloride (PVC)
Polyvinyl Chloride (PVC) is highly resistant to corrosion, making it an ideal material for parts exposed to harsh environments. Its ability to produce high-quality components with complex geometries and tight tolerances makes it a preferred choice in the automotive, electronics, and medical device industries. PVC is also extensively used in construction and durable consumer products due to its versatility and longevity.
Common Applications: PVC is corrosion-resistant, making it ideal for automotive parts, electronics insulation, and medical devices. It’s also extensively used in construction materials and durable consumer products due to its versatility and long-lasting properties.
Plaster
Plaster is an affordable and highly workable material, commonly used for creating both simple and complex molds. Its ease of use and cost-effectiveness make it a popular choice in applications such as architectural modeling, dental molds, industrial design, and artistic creations. Plaster’s versatility allows for detailed and precise replication of intricate designs, making it a valuable tool in various fields.
Common Applications: Plaster is cost-effective and easy to mold, used in architecture, dental molds, industrial design, and art. Its versatility makes it ideal for creating detailed models, prototypes, and decorative elements.
Frequently Ask Questions
How accurate is vacuum casting?
Vacuum casting is highly precise, capable of replicating features down to a few microns. Tolerances are typically controlled to ISO 2768 standards, with the possibility of tighter tolerances for critical features.
Is vacuum casting permanent?
No, vacuum casting is not a permanent manufacturing method. It is primarily used for prototyping and low-volume production, with silicone molds usually lasting for about 20-30 castings before needing replacement.
What is the minimum thickness for vacuum casting?
The minimum thickness for vacuum casting varies by material but can be as thin as 0.5 mm. Very thin sections may be challenging to cast properly and may require special techniques.
What keeps the mold together in vacuum casting?
In vacuum casting, the silicone mold is kept together by its inherent elasticity and often a supporting frame or box. The vacuum process helps remove air bubbles, ensuring the mold is completely filled.
What is the alternative to vacuum casting?
Alternatives to vacuum casting include injection molding, 3D printing, and CNC machining. Each method offers distinct advantages depending on factors like production volume, material properties, and precision.
What is the difference between thermoforming and vacuum casting?
Thermoforming involves heating a plastic sheet and forming it over a mold using vacuum, suitable for large, thin parts. Vacuum casting involves pouring liquid resin into a silicone mold under vacuum, ideal for smaller, detailed parts.
What is the best resin for vacuum casting?
Polyurethane (PU) is commonly used for its versatility, but resins such as epoxy or silicone can also be selected based on desired mechanical properties, including flexibility, durability, or heat resistance.
Which material is most commonly used in vacuum forming?
ABS is one of the most commonly used materials in vacuum forming due to its excellent balance of formability, strength, and cost-effectiveness.
