Vacuum Casting Services — Urethane Casting From China
- For Product-Grade Plastic Parts
- for Prototypes & Small Batch Production
- Deliver in 7-10 days
RpProto is a professional vacuum casting manufacturer based in Xiamen, China. We help product teams create high-quality plastic prototypes and small-batch parts using silicone molds and polyurethane resins — without the cost or lead time of steel injection molds.
Our facility runs eight dedicated casting machines capable of handling parts up to 2200 × 1200 × 1000 mm, with a full range of material options including ABS-like, PMMA-like, rubber-like, PP-like, and nylon-like resins.
Why Choose Vacuum Casting with RpProto?
Fast Turnaround
Get your parts in 7-10 business days, enabling rapid project turnaround and market testing.
Low-Cost Silicone Molds
Affordable tooling with fast setup and minimal upfront investment.
Complex Geometry Capability
Flexible silicone molds accommodates intricate details, undercuts, and fine features that rigid tooling cannot capture
Versatile Materials
We offer a broad selection of product-grade polyurethane resins — from rigid formulations that mimic ABS, PC, and Nylon, to flexible rubber-like materials with adjustable Shore hardness, as well as optically clear and color-pigmented options.
Appearance & Functional Prototypes
Excellent for both visual models and functional testing with near-production quality.
Low-Volume Production Ready
Ideal for short runs of 10–200+ parts, supporting pilot production and market testing.
Bridge Production Solution
Ideal for pre-production runs while waiting for injection mold fabrication—maintain momentum without delays
Vacuum Casting Technical Specifications
Vacuum casting bridges the gap between prototyping and production. It’s the smart choice when you need more than a few 3D prints but aren’t ready for injection molding tooling investment.
Our urethane casting capabilities cover a wide range of part sizes and complexities. Review our standard specifications below.
| Specification | Industrial Casting Capabilities |
|---|---|
| Maximum Part Size | 2200mm*1200mm *1000mm |
| Standard Tolerance | ±0.15mm or ±0.3% (whichever is greater) |
| Minimum Wall Thickness | 0.75 mm (1.5mm recommended) |
| Surface Finish | As cast, sanded, painted, textured |
| Parts Per Mold | 10-20+ depending on complexity |
| Lead Time | 5-7 business days (standard) |
| Rush Lead Time | 3-4 business days available |
| Minimum Order | 1 part |
RpProto's Manufacturing Edge
- 8 industrial-grade casting machines (largest in Xiamen, China)
- ISO 9001:2015 certified facility
- Free DFM (Design for Manufacturing) review
- NDA protection for all projects
Our Urethane Casting Capabilities
- ABS-like, PC-like, rubber-like PU materials
- Clear and colored polyurethane parts
- Rigid, flexible, and impact-resistant options
- Textured or smooth finishes
- High detail and sharp feature replication
- Insert and overmolded parts available
Urethane Material Properties
We offer a wide range of urethane casting materials that simulate the properties of ABS, PMMA, nylon, rubber, TPU, and TPE — helping you achieve the right fit, form, and function for your project.
| References | Description | Hardness (shore) | Strength （MPa） | Elongation (%) | Tg (°c) | Colour |
|---|---|---|---|---|---|---|
| Hei-CAST PU8150 | Well-balanced physical properties, excellent cure properties and superior dimensional stability , high practical strength | 84D | 73MPa | 16% | 85°c | Amber,white and black |
| Axson UP4280 | Easy processing, High mechanical properties, Good heat resistance up to 100°C | 81D | 84MPa | 13% | 93°c | Dark Amber |
| Axson PX 100 | Low viscosity. Manual application possible. Long pot life. | 74D | 40MPa | 20% | 75°c | White/Black |
| Axson PX 527 | Like ABS type or PC. Good impact and flexural resistance. Clear aspect. Can be easily coloured with CP pigments. | 80D | 73MPa | 13% | 80°c | White/Black |
| Axson PX 223 HT | Low viscosity. Good impact resistance. High temperature resistance. Temperature stability up to 110°C. | 80D | 60MPa | 11% | >120°c | black |
| Axson PX 245 / PX245L* | Filled.Very short demoulding time. Very rigid. Good abrasion resistance. | 85D | 85MPa | 3% | 95°c | off white |
| References | Description | Hardness (shore) | Strength （MPa） | Elongation (%) | Tg (°c) | Colour |
|---|---|---|---|---|---|---|
| Axson PX 522 HT | The same properties as PMMA, cristal PS, MABS. High transparency, Easy polishing, Good UV resistance. | 87D | 75MPa | 9% | 110°c | transparent |
| Axson PX 521 HT | For crystal glass like parts. High transparency (water clear) , Easy polishing ,High reproduction accuracy . | 87D | 75MPa | 9% | 110°c | transparent |
| AXSON UPX 5210 | For crystal glass like parts. High transparency, Easy polishing, High reproduction accuracy , Low shrinkage | 83D | 65 – 70 MPa | 15 – 20% | 80°c | transparent |
| Axson PX 225 | Low viscosity for easy casting. Good impact and flexural resistance. Very easy coloring with all kind of pigments. | 80D | 70MPa | 15% | 80°c | transparent |
| References | Description | Hardness (shore) | Strength （MPa） | Elongation (%) | Tg (°c) | Colour |
|---|---|---|---|---|---|---|
| Axson UPX 8400 | Rubber-Like, Easy to process and pigment, outstanding strength, low aggressiveness to silicone moulds | 20A-85A | 6-22MPa | 450-660% | 80°c | off white |
| Hei-Cast T0387 | Cured material is transparent. Hardness in a range from Shore A 30 to 80. | 30A-80A | 1.5-40MPa | 260-300% | 60°c | Clear |
| References | Description | Hardness (shore) | Strength （MPa） | Elongation (%) | Tg (°c) | Colour | |
|---|---|---|---|---|---|---|---|
| SPECIFIC, TECHNICAL PLASTICS | |||||||
| Hei-CAST PU8263 | Well-balanced physical properties, difficult-inflammability and excellent dimensional stability | 83D | 68MPa | 15% | 80°c | white | |
| Axson PX 330 | Conforms to FAR 25 (fire resistance) standard. Easy to use. Compliance ROHS. | 87D | 70MPa | 3% | 100°c | white | |
| HDPE – PP type | |||||||
| Axson UP5690 | High elongation, High impact resistance, no breakable, Easy processing, Good flexibility | 75-83D | 25-35MPa | 50-90% | 70°c | White/Black | |
Flame Retardant (UL 94-V0) material, high temperature material, clear and medical imaging materials are all available.
Surface Finishing for Vacuum Cast Parts
Post-machined to achieve tight tolerances
Talk to our expert to discuss your Urethane Casting post-processing needs.
Urethane casted parts are left with print layer lines (generated by 3D printed master patterns) and potentially sharp edges and burrs. Polishing gives the parts a smooth and close-to-product look.
Parts can be painted to your selected color for 2-4 times.
Vacuum Casting Applications by Industry
Plastic Prototypes
Urethane casting is a perfect way to create functional and cosmetic prototypes to validate product designing.
Low-volume Plastic Production
Urethane casting is ideal to make small batches (20 - 100 units) newly developed products to test the market.
Urethane casting give you real production-quality parts before committing to injection mold tooling.
The process serves a wide range of industries, including medical devices, automotive, aerospace, and consumer electronics.
Vacuum Casting Process
Vacuum casting process uses silicone molds with urethane resin material to produce high-quality parts rapidly. It can be used for bridge tooling between a prototyping and injection molding to effectively balance quality, cost, and time. The process has four steps.
1.Master Patterns
2. Positioning of the model in a box and casting of silicon
3. Mold cutting and RP model removal
4. Polyurethane or other material casting
5. Printed model with inlet to be removed
Step 1 – Creating the Master Pattern
Before making the silicone mold, you need to make a master pattern, which can be made by cnc processing or 3D printing. Start making the silicone mold, and mix the silicone and curing agent evenly. The appearance of the silicone mold is a flowing liquid, and the component A is silicone. The B component is the curing agent.
Step 2 – Degassing the Silicone Mixture
After the silica gel and the curing agent are evenly stirred, perform the vacuuming to remove the bubbles. The vacuuming time should not be too long. Under normal circumstances, it should not exceed ten minutes. If the vacuuming time is too long, the silica gel will solidify immediately, resulting in a cross-linking reaction. The silica gel becomes piece by piece and cannot be painted or poured.
Step 3 – Applying Silicone to the Master Pattern
The silica gel that has been evacuated and evacuated can be brushed or poured. Pour it on top of the product (Note: The product or model to be copied before pouring the silica gel must be coated with a release agent or release agent). Then apply the silica gel on the product. The application must be even. After 30 minutes, paste a layer of gauze and weft cloth to increase the strength and tensile force of the silica gel.
Step 4 – Building the Outer Mold Shell
The generally used method and material is to surround the mold with rubber sheets or wooden boards, and fill the mold cabinet with plaster. The other method is to use resin brushing. After applying a layer of resin, a layer of glass is pasted. Fiber cloth, brush and paste, repeat two or three layers to complete the outer mold of the mold.
Step 5 – Casting the Final Polyurethane Part
Pouring molds or perfusion molds are used for relatively smooth or simple products. There is no mold line to save labor and time, that is, to copy the product or model you want to copy, pour the vacuumed silica gel directly onto the product, and wait for the silica gel to dry and form After that, take out the product. (Note: The perfusion mold is usually made of soft silicone, so that it is easier to demold and will not damage the product in the silicone mold).
Start Your Vacuum Casting Project
Upload your 3D files to get a quick quote for your urethane casting prototypes and production.
- All of your files are safe and confidential.
Vacuum Casting FAQs
What is vacuum casting/urethane casting?
Vacuum casting is a rapid manufacturing process that creates plastic parts by pouring liquid polyurethane resin into flexible silicone molds. The process takes place under vacuum pressure to eliminate air bubbles, resulting in smooth surfaces and consistent wall thickness — closely replicating the look and feel of injection-molded plastics.
Why would you use vacuum casting?
When you need a small quantity of production-quality plastic parts (between 10 and 200 pieces), without the long lead time and hefty expense of building a plastic injection mold . Vacuum casting is suitable for making appearance prototypes, like non-mechanical end-use parts like cases and covers.
What is the difference between vacuum casting and injection molding?
Vacuum casting uses silicone molds and polyurethane resins, making it ideal for low volumes (10-200 parts) with no tooling investment. It faster and cheaper to start.
Injection molding uses precision-machined steel molds and is cost-effective for high volumes (500+ parts) . It requires significant upfront tooling costs but offering extremely low per-part costs at scale.
Since injection molding have high tooling cost. Our customer often choose urethane casting to test marketing before they invest in an injection molding tool.
Can you match specific production plastics?
Yes, we have polyurethane resins that simulate properties of ABS, PP, PE, PC, nylon, rubber, and more. While not identical, they provide similar mechanical properties for functional testing.
How many parts can I get from one mold?
Typically, a silicone mold can produce 10-20 parts depending on part complexity, material choice, and required quality level. Simple parts with soft materials may yield more, while complex parts with rigid materials may yield fewer.
Can urethane cast parts be painted or finished?
Yes! We offer various finishing options including custom color matching, painting, texturing, plating preparation, and assembly. Parts can be finished to match production intent.
How accurate are urethane cast parts?
Standard tolerance is ±0.15mm or ±0.3% of the nominal dimension, whichever is greater. Tighter tolerances may be achievable depending on part geometry and can be discussed with our engineering team.
How much does it cost?
The total project cost varies depending on material selection, part complexity, and total quantity. It generally consists of three primary components:
- Master Pattern: $300-1500. The cost of producing the initial high-precision model (usually via SLA or CNC machining) used to create the mold.
- Silicone Mold: $200-800. The cost of creating the flexible mold around the master pattern. Note that one mold can typically produce 15–25 high-quality parts before needing replacement.
- Casting and Finishing: $15-80. The cost of the polyurethane resin, the vacuum casting process, and any secondary labor required for degating and surface finishing.