HomeBusinessUnderstanding Vacuum Casting: Its Process, Applications, and Benefits

Understanding Vacuum Casting: Its Process, Applications, and Benefits

There are many manufacturing techniques available in producing parts and products. But the vacuum casting technique is always a contender. With the improvement in technology, it has become a more reliable process that can make functional products.

The most common vacuum casting process is the use of silicone molds. That’s the reason why some people in the industry call this method ‘silicone vacuum casting.’ The products made from this process are of high quality and require a lesser time to make compared with other techniques.

If you are interested in vacuum casting, this article will answer what processes are involved, some of its applications, and benefits.

Components of Vacuum Casting

The vacuum casting process is a replication technique used to manufacture high-quality prototypes, parts, and products in low and high volumes. It used pourable materials including molten metals, plastic, or rubber to make the final product and a reusable silicone mold to make exact replicas of the master pattern.

There are two main components in vacuum casting: the master pattern and the mold.

The Master Pattern

The vacuum process begins with the master pattern. This master pattern is a prototype of the product and it’s made from a durable material made from 3D Printing or CNC machining. These two prototyping techniques are the most common because they can create prototypes quickly. And both of them do not need additional tooling and can easily accommodate changes.

Once the patterns are ready, they are perfected using different finishing methods. It undergoes sanding, painting, and polishing until the desired surface finish is achieved. For products with multiple parts, the pieces are assembled to make sure that they fit. If they do not, minor adjustments will be made to ensure that they appear perfectly done.

The Mold

The second component of the vacuum casting process is making the mold. When the patterns are ready, they are put in a casting box. This box is filled with liquid silicone and cured for several hours inside an oven. In this process, the silicone material will solidify. After it cools down, the casting box will be taken apart leaving only the silicone mold and the pattern.

This mold will be carefully cut in the established seam line and the pattern is removed. What is left behind is a hollow cavity that is the exact copy of the pattern.

The Vacuum Casting Process

The second part of the vacuum casting process is resealing the mold with a feed tube attached to its cavity. When it’s done, a liquid urethane resin is injected into the mold through the feed tube. The mold is then placed into the vacuum chamber to continue the process.

In vacuum casting, the vacuum is a critical part of the process. It removes the air out of the cavity and thereby, removing any air bubbles while the resin fills out the entire space. The mold is placed again in the oven to cure the resin. After it cooled down, the product extracted from the mold will be a perfect copy of the original pattern.

Applications of Vacuum Casting

Vacuum casting is ideal for rapid manufacturing or demands for short production runs. There might be three steps involved before you can have the final product but the process is swift and can deliver within the deadline.

It can be a preferred process for prototyping. This manufacturing technique is also favorable for early market testing and customer evaluations because the finished product has great aesthetics. It can be used for marketing launch and product presentations too.

The vacuum casting process can result in high-quality products compared with other techniques. What makes the products from vacuum casting exceptional is their fine degree of finishing. It can have a tough exterior and a shiny appearance. Therefore, perfect for products that demand a high-quality finish, vacuum casting should be the way to go.

Benefits from Using Vacuum Casting

Why is vacuum casting good for your next project? Here are the advantages when you choose this manufacturing process.


Unlike other manufacturing processes that need more time in producing high-volume quantities that could take weeks, vacuum casting only requires days to complete. Creating the silicone molds does not take long in this process. It’s a critical factor especially when the project is on a tight deadline.


One of the best characteristics of the final product from vacuum casting is its quality. The process can replicate even the fine surface details of the original. This is why much emphasis is put on creating the master patterns. The quality of the finished part will depend on it.


One of the concerns for companies before deciding on a manufacturing technique is the cost. Many are afraid to choose vacuum casting due to its needed master pattern and mold. However, with new technologies like 3D printing, the costs have reduced drastically.

When the master patterns have been arranged, the vacuum casting process is the most cost-effective method to create high-quality copies. Unlike in pressure die casting or injection molding, there is no investment in hard tooling here. The savings in vacuum casting can be used for other purposes like product development or making design iterations.

There is also less use of electricity in this process compared with injection molding. When you add them together, there are plenty of ways you can save from vacuum casting. From tooling to materials, to labor and energy costs.


The last and not the least benefit that companies can get from vacuum casting is versatility. This process can replicate the appearance, texture, and functionalities of most thermoforming resins like ABS, nylon, or polyethylene.

In vacuum casting, you don’t have to sacrifice the functionality of the product for convenience and speed. It can even accommodate different types of urethanes to create various hardness and textures in one piece.

Final Thought

Vacuum casting can be a perfect solution for producing end-use parts and rapid prototypes. The possibilities with this production process are endless and with its high-quality finishes, it has attracted a lot of followers. You will not find this kind of finishing from other techniques.


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