Vacuum Casting
What is Vacuum Casting?
Vacuum casting is a practical and cost effective way to transform your design from a concept into a physical prototype that exemplifies the quality, aesthetics, and even function of a final, mass-produced item.
To help you understand if vacuum casting would be an appropriate choice for your project, we’ve outlined some key advantages and disadvantages below.
To help you understand if vacuum casting would be an appropriate choice for your project, we’ve outlined some key advantages and disadvantages below.
Key Advantages
- Material Versatility : Vacuum casting allows for a wide selection of resins that can mimic various thermoplastics, providing flexibility in prototype function and aesthetics. Rubber materials can also be used, according to project specifications.
- Cost Efficiency : Particularly cost-effective for small series production, vacuum casting circumvents the high costs associated with hard tooling, making it ideal for low-volume manufacturing.
- Speed to Market : The rapid turnaround from master model to finished parts enables faster design iterations and significantly reduces the time to market for new products. It usually takes a few days to produce a silicon mold, whereas producing an aluminum or steel mold can take weeks.
- High-quality Finish : The process excels in producing parts with excellent surface finish and detail fidelity, critical for functional testing, consumer testing, and marketing samples.
- Design Flexibility : Vacuum casting is conducive to producing complex geometries, overmolding, and integrating multiple materials into a single part, offering substantial design flexibility.
Key Disadvantages
- Mold durability : The silicone molds used in vacuum casting degrade over time and with use. They usually have a limited lifespan, often capable of producing only 20 to 25 copies before the quality of the parts starts to decline. For this reason, vacuum casting is only a viable option for low volume production.
- Size limitations : As the size of the product increases, it becomes more challenging to create the vacuum necessary to evacuate all the air bubbles from the mold and the resin. At our capacity, we can vacuum cast products up to 1 cubic meter.
- Material limitations : While the resins used in vacuum casting can be selected for a range of properties, they generally do not match the strength and durability of parts made from metal or produced through injection molding with engineering-grade plastics. This can limit the use of vacuum-cast parts in some functional applications.
Our Process
Before beginning the vacuum casting process, our team of designers and CAD engineers will work with you to refine your product design in order to ensure that it is ready for the prototyping phase. The remainder of our process can be summarized in the following steps:
- 1. Creation of a Master Model : The initial step involves generating an accurate prototype of your design, which acts as the master pattern for the vacuum casting process. This prototype is usually fabricated using milling or 3D printing to ensure high fidelity to the original design specifications.
- 2. Mold Fabrication : Using the master model, a mold is constructed from silicone due its capability to faithfully replicate every aspect of the model, including intricate details and textures. This silicone mold functions as a versatile template for casting replicas of the design.
- 3. Casting Under Vacuum : The casting resin, typically a two-component polyurethane, is selected based on the desired mechanical, thermal, and aesthetic properties of the final part. Before pouring, the resin is degassed under vacuum to remove air bubbles. The silicone mold is then filled under vacuum, ensuring the resin precisely fills the mold cavity without entrapping air.
- 4. Curing and Post Processing : After the resin is cast, the mold is allowed to cure. Once cured, the part is demolded, and any necessary post-processing (such as painting, machining, or installation of inserts) is performed to meet the final specifications.
Are you interested in exploring the possibilities of vacuum casting for your project? Reach out to us here!