Vacuum Casting – Benefits of high-quality vacuum casting services

As a pioneer in the Dutch 3D printing industry, VRT has been offering leading vacuum casting services for nearly 28 years. We distinguish ourselves by exclusively working with high-quality industrial equipment, which allows us to produce small series of functional plastic parts with excellent properties. 

What is vacuum casting? 

Vacuum casting is an advanced production process where two-component polyurethane resin is cast into a silicone mold under vacuum. This technique is one of the most versatile production methods for creating small series of functional plastic parts. Vacuum casting stands out for its ability to produce high-quality prototypes and small production series with materials that mimic the properties of various thermoplastic materials. 

How does vacuum casting work?  

The vacuum casting process uses a silicone mold and liquid polyurethane resins. The process works according to the following principle: 

1. First, a master model is created, usually via SLA or SLS 3D printing technology 
2. The master model is placed in a frame and encased in liquid silicone that hardens into a flexible mold 
3. After curing, the silicone mold is opened and the master model removed 
4. The two halves of the mold are reassembled and placed in a vacuum chamber 
5. Under vacuum, two-component polyurethane resins are mixed and poured into the mold 
6. The vacuum removes air bubbles from both the mold and the resin material 
7. After curing (typically 30-60 minutes), the part is removed from the mold 
8. The mold can be reused approximately 25 times for the same parts 

Since the process takes place under vacuum, air bubbles are effectively removed, resulting in dense, strong parts without internal defects. 

Benefits of vacuum casting    

Vacuum casting offers a perfect balance between quality, speed, and cost for small series and prototypes. The technique is known for its flexibility and low startup investment. 

The main benefits include: 

• Wide range of materials – Various resins that mimic properties of ABS, PC, PP or POM

• Rapid production – From master model to first parts in 3-5 working days

• Low investment costs – Silicone molds are much cheaper than metal injection molds

Additionally, vacuum casting provides excellent detail reproduction, suitability for complex geometries, and the ability to cast different resins in the same mold. This combination makes the technique ideal for high-quality prototypes and small series without major investments. 

What are the limitations of vacuum casting?     

While vacuum casting offers many advantages, the technique also has some limitations: 

• Limited mold life: Maximum of approximately 25 pieces per silicone mold

• Accuracy: Not as precise as injection molding for dimensioning

• Post-processing required: Each cast part requires some manual finishing

• Special colors: Often require painting or other post-processing

• Series size: Economically feasible up to about 25-50 pieces; injection molding is often more cost-effective for larger quantities

Vacuum casting versus other techniques      

Vacuum casting versus injection molding     

Vacuum casting differs from injection molding in that it requires significantly lower mold investments, making it a more economically attractive option for small production runs. While an injection mold can easily cost thousands of euros, the costs for a silicone mold for vacuum casting remain limited. Another important advantage is the faster turnaround time; vacuum cast parts can be produced within days, while injection molding typically takes weeks for initial production. However, injection molding gains ground with larger production series of more than 100 pieces, where the initial investments are recovered through lower cost per part. Injection molding also offers a wider range of material possibilities, while vacuum casting is limited to polyurethane resins that mimic thermoplastic properties.

Vacuum casting versus vacuum forming      

When comparing vacuum casting to vacuum forming, we see that vacuum casting offers clear advantages for complex geometries. Vacuum casting makes it possible to create internal features and intricate structures that are not feasible with vacuum forming. Another significant advantage is that vacuum cast products have a consistent and uniform wall thickness, while vacuum formed products often become thinner in certain areas. In terms of material variation, vacuum casting also offers more flexibility; various polyurethane resins can simulate different mechanical, thermal, and optical properties. Vacuum forming, on the other hand, has its own advantages, particularly for large, thin-walled parts such as housings or packaging, where the speed and cost efficiency of the process come into their own. 

Vacuum casting machines and materials       

We have modern vacuum casting equipment for projects of any size: 

Mechanical properties of vacuum casting materials   

The material properties of vacuum cast parts vary depending on the resin used: 

• Tensile strength: Ranging from 30 to 75 MPa, depending on the material type

• Elongation at break: From 3% for rigid materials to 350% for flexible variants

• Hardness: From Shore A25 (very flexible) to Shore D85 (very hard)

• Temperature resistance: From 60°C to 140°C, depending on the material type 

• Impact resistance: From brittle to very tough, depending on the chosen material

Thanks to this diversity, we can select materials that perfectly match the functional requirements of your specific application. 

Why choose our vacuum casting service?       

Almost 28 years of experience and expertise

As one of the pioneers in the Dutch rapid prototyping industry, we have unparalleled expertise in vacuum casting technology. We understand all the possibilities and limitations, allowing us to always provide the best advice for your specific application.

Honest and reliable advice

We don't sell empty promises. Our advisors provide honest advice about what is and isn't possible with vacuum casting, including the advantages and disadvantages for your specific project. This transparent approach helps us avoid disappointments and ensures you have realistic expectations of the end result. 

Complete service from design to finishing

In addition to vacuum casting, we offer a comprehensive service that covers all aspects of product realization. We provide professional finishing and painting according to specifications, produce small series, perform additional processing, and support the transition to injection molding with low mold investments when larger volumes are needed. This end-to-end approach allows you to go from concept to end product with just one reliable partner.

Application areas for vacuum casting        

Vacuum casting technology is particularly suitable for various applications: 

• Functional prototypes with material properties that mimic the final product

• Small production series of 5-25 pieces with consistently high quality

• Jewelry industry for precise and detailed models

• Medical devices with biocompatible FDA-approved materials

• Consumer products for market validation before large investments

• Artwork and visual arts with high-quality finishing

• Master models for other production processes such as metal casting

• Design prototypes for visual evaluation and user testing

Contact us for your project        

Would you like to know more about our vacuum casting service or do you have a project you'd like to discuss? Contact us for a free consultation. As a Dutch service provider, we respond quickly, think flexibly, and deliver locally with short lines of communication. 

Discover why leading companies have trusted our vacuum casting expertise for nearly 28 years. Choose quality, experience, and reliability with Venture Rapid Technologies.