To deliver bubble-free, void-free parts we follow one standardized workflow. A high-quality master model — produced by high-accuracy CNC machining — is prepared first. Liquid silicone rubber is poured around it inside a mold frame; once cured at a controlled temperature the mold is split and the master removed, leaving an accurate silicone cavity ready for casting.
Our engineers design gas vents during mold-making to guarantee flawless surfaces. Each silicone mold yields 10–20 high-quality copies, and a single project can run from one part up to 2,000 pieces across multiple molds — the bridge between prototyping and injection production.
We provide complete custom vacuum casting, not just casting. Post-processing includes polishing, silk screening, laser etching and chrome plating, so parts for visual models or functional testing look and perform like end-use production.
Process steps:
1. Produce high-accuracy master model via CNC or SLA
2. Prepare and de-air the liquid silicone rubber
3. Pour silicone around the master under vacuum
4. Cure the silicone mold and carefully extract the master
5. Inject liquid polyurethane resin into the silicone cavity
6. Cure the resin in oven and demold the final part
The variety of polyurethanes available is so great that almost any material used in the finished product can be imitated using this process. Products used to copy material: PU, imported PU, transparent PU, soft PU, ABS, PP, and PC. It is even possible to create transparent, strengthened, colored and rubber prototypes.
With our Vacuum Casting Machines, we can produce standard parts as well as shaped parts (such as bearing sleeves or stud bolts) and reproduce the prototypes with original color, texture and geometries from prototypes to components. The range of polyurethanes is so broad that almost any production material can be imitated. We cast standard and shaped parts — bearing sleeves, stud bolts, enclosures — reproducing the original colour, texture and geometry so the casting matches the mechanical behaviour of a steel-molded part. With our 4 vacuum casting chambers we reach extremely fine detail and satisfy tool makers' production-tooling requirements.
KAIAO operates large-capacity vacuum casting chambers with a maximum mold envelope of 2,000 × 1,200 × 1,000 mm. This lets us produce seamless, single-piece low-volume runs of oversized components — automotive instrument panels, bumpers, door inner trims, medical device enclosures — with full structural integrity and no partition bonding.
Beyond standard casting, our silicone tooling supports four techniques our clients rely on for complex, multi-material and insert parts.
• Over Molding is an advanced process of casting around and/or through Cores that are inserted into the Cavities of Molds, resulting in the production of Individual parts made of multiple materials. Typically, a soft PU Resin is cast around and/or through a hard PU Resin to produce one part with two different Durometers and Colors. Additionally, transparent parts such as PMMA lenses can be cast directly into housings. This process allows for Hand Held products and Electronic Devices to be manufactured to meet (Vibration Minimizing, Impact Resistant, and Water Resistant) Functional Requirements.
• Metal Part Inserting is a mechanical process where PU Resins are cast around and/or through Metal Parts that have been inserted into Mold Cavities to produce IN-MOLD ASSEMBLED PARTS. Machined Metal Parts, Stamped Metal Parts, Cast Metal Parts, as well as Brass Inserts can all be Over Molded to improve the mechanical strength, durability, and usability of parts with Functional Requirements.
• Melt Molding is a special process where Cores are cast using Wax or Low Melt Temperature Alloys. These Cores are then placed inside the Mold Cavities. The Over Molded Parts are removed from the Molds with the Cores still inside. The Cores are then melted out using a heat gun and/or hot water. Through this process, complex radiator pipes and corrugated tubing can be custom manufactured.
• The Coloration of Cast Parts is a creative process where Colors are added directly into the PU Resins to make IN-MOLD COLORED PARTS. To Achieve IN-MOLD Texture and Gloss, we apply 2K paint onto the surface of the Master Patterns, which is copied into the Silicone Tool, allowing for parts to be produced with minimal Post Production Finishing and are similar to Plastic Injection Molding.
