Vacuum Casting Services (Urethane Casting)

Look-like/feel-like parts—fast. KaiSpeed casts rigid, clear, and rubber-like polyurethane from silicone molds to deliver production-grade appearance and fit, ideal for design reviews, user tests, and bridge builds.

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What is Vacuum Casting?

Vacuum casting (also called urethane casting) is a cost-effective way to make low-volume plastic parts that closely simulate injection-molded products—both in appearance and feel. A high-quality master pattern (often SLA or CNC) is used to create a silicone rubber mold. Under vacuum, liquid polyurethane fills the cavity and cures, reproducing fine details, textures, wall thicknesses, and color with consistent surface quality from part to part.

Vacuum Casting Process

Step 1 — Master Pattern Build & Finish

We create a master from your CAD—typically SLA 3D printing for fine surfaces or CNC machining for tight geometry. Masters are finished and inspected (sanding/polish/prime as needed) in a temperature-controlled environment to ensure the silicone captures every detail.

Step 2 — Silicone Mold Making

The master is positioned in a mold box and encapsulated with liquid silicone. We vacuum-degas the silicone to remove air, then cure it under controlled heat. After curing, the mold is split along a planned parting line with alignment keys, and the master is removed—leaving a cavity that mirrors the original, including textures and fine features.

Step 3 — Casting, Curing & Demold

Two-part urethane resin is mixed (with optional pigment), de-gassed, and cast under vacuum into the preheated silicone mold. After curing, parts are demolded, gates/flash are trimmed, and any required post-cure is performed. We then proceed with finishing (e.g., paint, tint, polish, texture) and optional insert installation or light assembly.

Advantages of Vacuum Casting

  • Low tooling cost

    Silicone molds eliminate the expense and lead time of hard metal tooling—ideal for prototypes, pilot runs, and bridge production.

  • Fast delivery

    From master to first articles in days; dozens of parts are commonly achievable in roughly 1–2 weeks, depending on size, finish, and quantity.

  • Wide material portfolio

    PU resins from soft and flexible (Shore A) to rigid and impact-resistant (Shore D), including clear/translucent, high-temp, and flame-retardant options.

  • High fidelity & repeatability

    Excellent detail replication and stable cosmetics; typical part accuracy around ±0.10–0.30 mm (geometry-dependent).

  • Production-like finishes

    Smooth, uniform surfaces that take paint, tint, texture (Mold-Tech-style), logos, and clear polishing—often superior to raw CNC/3D-printed surfaces.

Vacuum Casting Technical Specifications

Typical lead time Up to 20 parts in 15 days or less, depends on the part specification and volumes.
Accurate
± 0.3% (with lower limit on ± 0.3 mm on dimensions smaller than 100 mm)
Minimum wall thickness
To ensure that the mold is filled properly, a wall thickness of at least 0.75 mm is necessary. For best results, we recommend a wall thickness of at least 1.5 mm
Maximum part dimensions
The size of the mold is limited by the dimensions of the vacuum chamber (1900 x 900 x 750 mm) and by the volume of the product (maximum volume: 10 liters)
Typical quantities
Up to 25 copies per mold (depending on the mold’s complexity and the casting materials)
Color & Finishing
Pigment is added to the liquid polyurethane prior to casting, custom painting and texture.

Why KaiSpeed

  • Production-like cosmetics: Gloss/matte, Mold-Tech-style textures, logos, color matching (Pantone/RAL).

  • Material breadth: Rigid, tough, clear/translucent, rubber-like (Shore A), high-temp and flame-retardant PU grades.

  • One-stop finish & assembly: Paint, tint, vapor/hand polish (clear), inserts, threaded features, bonding, gasket install.

  • Engineer-led DFM: Guidance on wall thickness, ribs/bosses, draft, gating/parting lines, and assembly stack-ups.

  • Smooth ramp: Bridge quantities now; move to rapid tooling when you’re ready to scale.

24/7 Support • Fast Global Delivery • Secure NDA Protection

How to Work With Us

01. Upload Your CAD

Choose your process (CNC, sheet metal, injection molding, 3D printing, etc.) and upload your files.

  • NDA-backed confidentiality

  • Secure transfer (STEP/IGES/ PDF)

02. Get Quote & DFM

Select material, finish, and quantity. Receive a clear quote plus DFM feedback to optimize cost, lead time, and quality.

  • Typical  within 24 hours

  • Alternative process/ material options when helpful

03. We Start Production

Once approved, we begin manufacturing to your drawing and GD&T requirements.

  • In-process QC and FAI on request

  • Photo updates and milestone reports

04. Receive Your Parts

After final inspection, we pack and ship to your door.

  • Dimensional/CMM reports available

  • Global shipping (NA/EU often 3–10 days)

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Materials & Surface Finish

  • PU Resin Families: ABS-like, PC-like, PP-like, rubber-like (TPU-style), clear optical, high-temp, flame-retardant

  • Colors/Textures: Pantone/RAL color match, Mold-Tech-style textures, matte/satin/gloss

  • Finishing: Sanding, bead-blast, painting, tinting, clear polishing (hand/vapor), decals, silk-screen, laser marking

  • Assembly: Brass/threaded inserts, magnets, windows, gaskets, adhesive bonding, basic sub-assemblies

FAQs

Typical tolerances are ±0.10–0.30 mm or ±0.3% of length (whichever is greater), depending on geometry, size, resin, and mold life. Good detail and surface finish make them suitable for functional prototypes and select end-use parts.

Very. It avoids hard tooling, so it’s ideal for ~10–100+ pcs. For higher quantities, multiple silicone molds can run in parallel (bridge production/early market tests).

Casting delivers better cosmetics, uniform surfaces, and consistent material behavior for low volumes. 3D printing is fastest for one-offs/complex internals but may trail casting on appearance and mechanical feel without extra finishing.

A typical silicone mold yields ~15–25 shots, influenced by part geometry, resin exotherm, textures, and required cosmetics. As molds age, precision and surface quality gradually decline.

A two-part silicone mold is placed in a rigid frame (“mother mold”)—usually aluminum or durable plastic—with alignment keys and clamps. The frame keeps halves registered, limits warp under vacuum, prevents leaks, and reduces flash.

Very close in appearance and feel. Mechanical performance depends on the PU resin chosen; for long-term, high-load, high-temp, or harsh environments, consider rapid tooling/injection molding.

Yes. Optical-style PU can be cast clear, then polished/tinted. We’ll highlight design features that affect clarity (thick sections, sharp internal corners, ribs on visible faces).

Yes—Shore 20A–90A elastomers. Over-mold-like casting onto rigid parts or post-bonding is available case-by-case.

By master complexity, mold count, resin, finish/assembly, and quantity. Share your CAD for a line-item quote and lead time.

STL/STEP for geometry, plus a PDF noting quantities, color/texture, cosmetic faces, and critical dimensions.

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