What is Vacuum Casting?
Vacuum casting is a precise molding technology that uses a vacuum environment to inject liquid resin materials into silicone molds. Unlike injection molding that relies on mechanical pressure injection, this process is carried out under vacuum, which effectively prevents bubbles and is particularly suitable for producing parts with fine textures, thin walls, or complex undercut structures.
Prototype production
Firstly, a highly accurate "main model" (prototype) is fabricated using CNC machining or 3D printing.
Making the silicone mold
Place the main model inside the frame, then pour the liquid silicone. After the silicone solidifies, cut it open and remove the main model, and you will obtain a reusable flexible silicone mold.
Vacuum casting
In a vacuum environment, the pre-mixed resin material is injected into the mold. The vacuum effect can completely eliminate air bubbles, ensuring that the parts are dense and defect-free.
Curing and Demolding
Place the mold filled with resin in an oven for curing. After cooling, the finished parts can be removed. The silicone mold can be reused approximately 15-20 times.
Advantages of Vacuum Casting
Fast turnaround
HLH can provide up to 20 parts in 15 days or less, depending on part specification and volume.
Superior surface finish to injection molding
The vacuum process removes air bubbles and allows the material to capture fine details.
Affordability
Silicone molds are less expensive than the tooling used for injection molding, resulting in low prices.
Color options
Coloring pigments can be added to the resin for a variety of color options.
Capable of producing large parts
Depending on the type of equipment used, vacuum casting can create very large parts.
Repeatability
The silicone mold can be used approximately 20 times before it needs to be replaced.
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Vacuum Casting Materials
Need help choosing a material? Use our Material Selection Tool
ABS-Like
ABS-Like is a general purpose polyurethane plastic that simulates ABS thermoplastic. This material is a great choice for most product enclosures.
Opaque Elastomer
Opaque Elastomer is a polyurethane plastic that simulates all kinds of rubber-like materials such as TPE, TPU, and silicone rubber. This material is great for wearables, gaskets, and overmolds and is available from Shore 20A to Shore 90A in 10A increments.
Acrylic-Like
Acrylic-Like is a stiff, transparent polyurethane plastic that simulates acrylic (PMMA). This material is great for see-through applications such as light pipes.
Surface finishes
Surface finishes can serve either a functional or aesthetic purpose. Surface finishes that serve both purposes are deemed cosmetic finishes, and are used for cosmetic parts. Producing cosmetic parts requires additional measures to minimize defects such as hang marks and scratches from tools.
How to Work With Us
Upload a CAD File
To start, simply select a manufacturing process and upload a 3D CAD file.
Get Quote with DFM
Within a few hours we'll send you design for manufacturability (DFM) analysis and real-time pricing.
Manufacturing Begins
Once you review your quote and place your order, we'll start the manufacturing process. We also offer finishing options.
Parts are Shipped!
Our digital manufacturing process allows us to produce parts in as fast as 1 day.