Polyurethane Vacuum Casting for Low-Volume Production
High-quality parts manufactured in silicone molds for functional testing, pre-series production, and industrial validation. Production-equivalent surface quality at prototype economics.
What is Polyurethane Vacuum Casting?
Vacuum casting is a manufacturing process where liquid polyurethane is poured into flexible silicone molds under vacuum conditions. The vacuum eliminates air bubbles and ensures precise replication of the master model — including fine surface texture, lettering, and complex geometry.
The process begins with a high-accuracy master pattern produced by SLA 3D printing or CNC machining. This master is encapsulated in two-part platinum-cure silicone to create a flexible mold. Each mold set typically yields 20–50 cast parts before requiring replacement.
ZenCore 3D vacuum casting produces parts with mechanical and surface properties that closely simulate final injection-molded components — making it the preferred bridge manufacturing process for validation batches, market testing, and production ramp-up.
Production Batch
Ideal for 5–50+ units
low NRE cost
Surface Fidelity
Class-A achievable
direct from mold
Material Range
15+ PU systems
rigid / flexible / optical
Fast Tooling
3–5 day mold
vs 6+ weeks for injection
Vacuum Casting Workflow
A structured 7-stage process from master model creation to finished, quality-inspected parts — fully documented for traceability and repeatability.
Master Model Creation
High-accuracy master pattern produced via SLA/SLS 3D printing or CNC machining. Surface finish Ra ≤ 0.8 µm achieved through post-processing.
Silicone Mold Preparation
Two-component platinum-cure silicone poured around the master. Mold halves separated and indexed for repeatable part alignment. Typical mold life: 20–50 shots.
Vacuum Degassing
Silicone mold and polyurethane components are degassed under vacuum (< 1 mbar) to eliminate entrapped air before pouring.
Polyurethane Pouring
Mixed two-component PU poured into mold under controlled vacuum. The pressure differential drives material into every cavity detail without voids.
Controlled Curing
Parts cured in temperature-controlled oven (60–70 °C for 30–60 min). Curing profile selected based on material system and wall thickness.
Demolding
Flexible silicone mold peeled away from cured part without draft angle requirements. Complex undercuts are released without tooling modification.
Finishing & Quality Check
Sprues removed, parting lines cleaned. Dimensional check vs CAD. Optional: painting, texturing, insert integration, and surface finishing.
Polyurethane Material Options
Four primary material families covering the full spectrum from optical-clear rigid parts to rubber-like flexible components and high-temperature variants.
Rigid Polyurethane
Most CommonApplications: Housings, enclosures, structural brackets, functional prototypes
Mechanical Properties
Shore Hardness
75D – 85D
Tensile Strength
40 – 65 MPa
Heat Deflection
60 – 90 °C
Elongation
3 – 8%
Applications
Vacuum casting addresses a wide range of engineering and production challenges across industries where low-volume, high-quality parts are required.
Functional Prototypes
Test-ready parts that match production material properties for fit, form, and function validation.
Pre-Series Production
Bridge production runs of 5–50 units while tooling for injection molding is in preparation.
Consumer Housings
High-surface-quality outer shells for electronics, appliances, and branded consumer products.
Automotive Interior Parts
Dashboard trim, centre console covers, and soft-touch interior components for vehicle programs.
Medical Device Casings
ISO-compatible materials for pre-CE prototyping, clinical evaluation units, and design validation.
Electronic Enclosures
EMC-shielded variants available. Snap-fit compatible. Insert moulding for threaded inserts and PCB mounts.
Production Capabilities
Our vacuum casting cell handles parts up to 600 × 400 × 300 mm with dimensional accuracy comparable to low-tolerance injection molds. Multiple finishing options are available including texture, painting, and insert integration.
Capability Specifications
per mold set
standard mold volume
whichever is larger
or textured/painted
pigment in-mix or paint
pre-placed before pour
from approved master
from order confirmation
Vacuum cast polyurethane parts — production batch
Available Post-Processing Options
When to Choose Vacuum Casting
Vacuum casting occupies a unique position in the manufacturing spectrum — higher quality than 3D printing, lower NRE cost than injection molding.
| Criterion | Vacuum Casting | 3D Printing | Injection Molding |
|---|---|---|---|
| Unit cost (5–50 units) | €€ — optimal | €€€ — high per-unit | € — but €€€€ tooling |
| Material properties | Production-equivalent PU | Good – functional resins | Exact final material |
| Surface quality | Class-A possible | Post-process required | Excellent |
| Tooling investment | < €1,500 silicone mold | None | €10,000 – €80,000+ |
| Lead time to first part | 7 – 10 days | 1 – 3 days | 4 – 8 weeks |
| Undercut complexity | Excellent – no draft needed | Excellent | Limited – draft required |
| Scale-up path | Bridge to injection mold | Not scalable to 10K+ | Full production |
| Best for | 5–200 functional units | 1–10 concept parts | 500 – 1M+ units |
Choose Vacuum Casting when…
- You need 5–200 production-quality parts
- Injection mold tooling is not yet justified
- Surface quality must match final product
- Complex geometry without draft angles
- Multiple material types in one program
Choose 3D Printing when…
- You need 1–10 concept or fit-check parts
- Internal geometry or lattice structures
- Overnight turnaround is critical
- Extreme geometric complexity
- Budget is very tight for one-off parts
Choose Injection Molding when…
- Volume exceeds 500+ units
- Exact final material properties required
- Long production run (3+ years)
- Tight tolerances (±0.05 mm)
- Cost per unit is the primary driver
Start Low-Volume Production
Upload your CAD file and receive a casting quote within 24 hours. Our engineers will recommend the optimal material and mold strategy for your application.