Will Vacuum Casting Still Have a Place in the World of 3D Printing?

08 Nov, 2023

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Photo by Mastars on Unsplash

Photo by Mastars on Unsplash

Is the Vacuum Casting process about to become obsolete? This is not an abrupt question. Vacuum casting is a widely used and cost-effective manufacturing solution for prototyping and low-volume production.

Is the Vacuum Casting process about to become obsolete? This is not an abrupt question. Vacuum casting is a widely used and cost-effective manufacturing solution for prototyping and low-volume production. However, with the rising popularity of 3D printing, which offers rapid and flexible manufacturing capabilities, particularly for prototyping and customized production runs, the question raises: Does vacuum casting still have a place in a world that is gradually being dominated by 3D printing? Let's explore this further.

The Rise of 3D Printing

Undoubtedly, 3D printing has made a significant impact across various industries. Its ability to rapidly produce complex designs, customized components, and functional prototypes has captured product developers and manufacturers, from aerospace and automotive to healthcare and more industries. As it continues to advance, 3D printing is expected to reshape supply chains and inspire further creativity in product innovation. However, there are still strengths of vacuum casting that 3D printing needs to catch up with.

The Strengths of Vacuum Casting

While 3D printing has been undoubtedly revolutionizing the manufacturing industry, vacuum casting retains several critical advantages that make it a preferred choice for specific applications:

Material Variety: Vacuum casting allows for the use of a wide range of materials, including polyurethanes, silicones, and elastomers. This versatility makes it suitable for applications requiring specific material properties, such as transparency, medical grade, thermal resistance and multiple colors. The vacuum casting process, provided by RPWORLD, is also available for overmolding with inserts, rubber and more to meet versatile application needs. 

Surface Finishes: Vacuum casting excels in replicating the master model with fine details, such as textures. This makes it ideal for creating prototypes with less post-processing, and high degree of visual and tactile requirements. Except for Stereolithography (SLA), which can produce detailed parts as well, 3D printing parts often present visible layer lines that need additional post-processing to achieve a smoother finish.

Low-volume Production Costs: Compared to 3D printing, vacuum casting requires silicone molds to cast each part, but these molds are more cost-effective than traditional injection molds. When the required part quantity is very low, such as dozens of parts, 3D printing offers an obvious price advantage. However, as production volume increases, the cost per part decreases, making vacuum casting the more cost-effective choice for low-volume production. This process enables the casting of multiple parts, around 20 parts in maximum, in a single mold, leading to reducing per-unit expenses.

Part Strength: The parts created by both 3D printing and vacuum casting can be strong. 3D printed parts can present anisotropic properties due to layering construction and may require careful attention to achieve strong layer adhesion. In contrast, vacuum casting uses polyurethane resins that offer good tensile and flexural strength. Vacuum casting parts are often featured with more consistent and homogeneous structure.

The Complementary Relationship

Both vacuum casting and 3D printing technologies are utilized by product developers and engineers to capitalize on their respective strengths. Here’re the comparison of both technologies:


3D Printing

Vacuum Casting


  Metals; plastics; silicone

 Variety of polyurethane resins; medical grade, thermal resistance materials; multi colors

  Surface Finishes

   Require post-processing

   Fine details

   Tooling Costs



  Part Strength

   Structure with anisotropy


  Part Precision

   Less precision or equal

  High precision

   Design Freedom

 Super high complex    geometries

    Complex geometries

    Production Speed

1 day

    3-7 days

As we can see, 3D printing offers speed and creative flexibility. It is right for rapid concept development. While vacuum casting excels in producing quality prototypes and low-volume parts with fine surface details, and can use production-grade materials. Though 3D printing continues to evolve and may incorporate the strengths of vacuum casting, these two technologies currently complement each other, and the choice should align with your project's specific needs. Our engineering experts are happy to give suggestions if you're unsure which to choose.

How Both Vacuum Casting and 3D Printing Shine at RPWORLD?

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RPWORLD is a leading high-mix, low-volume manufacturing service providers for CNC Machining, Injection Molding, Urethane Casting, Free DFM analysis. Our digital approach to manufacturing enables accelerated time to market, reduces development and production costs, and minimizes risk throughout th...