Vacuum casting is an important technique in rapid prototyping because it can complement other processes like CNC machining and 3D printing or can be a stand-alone process for producing high-quality prototypes.

Moreover, there are many reasons why it is preferred in product development. Keep on reading to find out more about this technique and how you can benefit from its application.

Whatis Vacuum Casting?

Before we move on to the benefits of vacuum casting, you need to have a grasp of its fundamentals.

The vacuum casting process is not a single-step process. It is composed of several simple steps. First is the creation of the master model via high-resolution 3D printing processes like stereolithography (SLA) or selective laser sintering (SLS). These are 3D printing methods. You can also use CNC machining as this process can create high-quality surface finishes, which resemble the properties of the master model.

This master model is then cast in silicone. It means submerging the master model in a vat and covered with liquid silicone. When the silicone mold is cured, it will be cut along a specific line to remove the master model. The space vacated by the master model is the mold.

This silicone mold is injected with a polymer-based resin and cured. The casting process is done under a vacuum to ensure that the trapped air bubbles are removed from the cast. It results in highly accurate and dense parts. When the resin is solid, the part will be removed from the mold and reused to create more identical parts.

Today, vacuum casting is used in many rapid prototyping applications. It is used for pre-series prototyping, testing, validation, and even in low-volume production of early-market products.

Benefits of Using Vacuum Casting for Rapid Prototyping

Quality: The first reason why many consider vacuum casting as a prototyping technique is that it can produce high-quality prototypes that closely resemble injected molded parts. The silicone mold can copy even the minute details of the master model. As such it is ideal for producing small and highly detailed components. A simple reminder though, the quality of the master model affects the vacuum molded parts. It should have a good surface finish and high-resolution features.

Choice of Materials: You will have a wide range of material choices in vacuum casting. While the material of the master model is not relevant, the final casting offers a broad selection of polymer resins, like plastics, elastomers, transparent materials, and many more.

Suitable for Testing: As mentioned, vacuum casting can produce parts with a high degree of accuracy and from a wide range of materials. As such it can create prototypes that are almost similar to the final product. It also means that these prototypes are suitable for functional testing and validation. It benefits the product developers because they can carry out quality assurance even at this early stage of product development before going to final production.

Time: Another reason why vacuum casting is always the first choice in prototyping is that it can help them save time and speed along the product development process. Unlike conventional molding processes like injection molding, there is no steel tooling required that takes weeks to make. Instead, it only uses a silicone mold that can be done in one day.

Cost: Vacuum casting is an economical way to produce quality prototypes and even small volume pre-series parts. It is not as energy-sensitive as CNC machining or injection molding. The creation of silicone mold is low-cost too.

Is Vacuum Casting for You?

Vacuum casting has many benefits for rapid prototyping applications. But the most important of them all is when high-quality prototypes are needed - you can turn to rapid prototyping as the solution.