Vacuum casting is a low-volume manufacturing process used to produce high-quality, functional plastic parts with excellent accuracy and surface finish. It is ideal for prototypes and end-use applications. It is a plastic manufacturing process that uses a vacuum to draw liquid resin into a mold. The mold is then placed in an oven, where the resin cures to form the final plastic part.

Vacuum casting is mainly used for producing plastics, the materials including ABS, PC, PP, NYLON, and TPU/PU/Rubber.

Please click HERE to view the technical data-sheet of these materials.

Geometric complexity，accuracy，roughness， cost of vacuum casting

Complexity

Vacuum casting has advantages in creating parts with high geometric complexity. It is not sensitive to the complexity of the structure, allow designers to have unlimited spatial imagination.

Complexity, From high to low

3D Printing > Vacuum casting > CNC Machining > =Injection Molding

Accuracy

ABS, PC, PP, NYLON with a tolerance of +/-0.1mm
TPU/PU/RUBBER with a tolerance of +/-0.3mm

Roughness or Smoothness

From high to low
Injection Molding >= Vacuum casting > CNC Machining > 3D Printing

Cost

Let’s take the part below/image an example,

Material: ABS
Quantity: 20 pieces

Cost from cheap to expensive
3D Printing (USD8/piece)<Vacuum Casting(USD26/piece) < CNC Machining(USD40/piece)

When we talk about vacuum casting, we usually compare it with injection molding. So, let’s distinguish the difference between them first.

Cost Comparison: Let’s take the mobile phone case as an example, the mold of the vacuum casting is only tens of dollars, while injection molding costs thousands of dollars. However, the production cost of vacuum casting is typically several tens of dollars per unit, whereas injection molding can reduce the cost to as little as 1 or 2 dollars.

In summary, vacuum casting requires a lower initial investment but has a higher per-part cost, whereas injection molding requires a higher initial investment but offers a much lower per-part cost.

Compared with 3D Printing（3DP), what’s the advantage of vacuum casting? Using the same material, vacuum casting provides a smoother surface finish, greater durability, higher dimensional accuracy, and virtually unlimited color options. 

How does it compare to CNC machining? Neither process is universally better. However, when prototype complexity, production efficiency, and tooling costs are key considerations, vacuum casting is often the better choice. While the CNC machining has more material options, the material performance is better.

Being able to make soft materials quickly is one of the biggest advantages of vacuum casting. It supports materials from Shore 30A to Shore 95A, from Shore 10D to Shore 90D, in any customized Pantone No.

In conclusion, vacuum casting is not intended to replace other manufacturing methods. Instead, it serves as a complementary process, providing greater flexibility and more manufacturing options for different production needs.

3D Printing(3DP), CNC Machining(CNC), Vacuum Casting( VC), Injection Molding(IM)

High Geometric structure: 3DP & VC are better
Dimensional accuracy: CNC & VC are better
Mechanical properties in all 3 dimensions: CNC & VC are better.
Lead time: CNC with 6-8 days, VC with 6-8 days, IM with 35 days, 3DP as fast as one day, 
Cost: Complex geometry or lightweight parts, 3DP and VC have more advantages.
Quantity: 3DP, CNC, and VC are suitable for low-volume parts, IM is more suitable for large volume parts.

Read more about 3D Printing Vs Vacuum Casting Vs Injection Molding.

If you have any questions about vacuum casting for your project, please feel free to contact us. Our experts will offer professional suggestions for your consideration.