Vacuum Casting: The process
The process of vacuum casting consists of multiple stages. The overall process is labor-intensive but
still relatively fast-paced and easy to manage. The process is described stage-wise as follows:
Creating a master model
First of all, a master model has to be created or obtained on the shelf. The master pattern can be an
industrial part or one created through rapid manufacturing techniques like 3d printing or CNC machine
tools. Elements created through 3d printing are created using stereolithography/SLS techniques. It must
be ensured that the master model used has the correct dimensions so that the final casting parts have
the desired dimensions.
Producing the mold
To make a silicone mold, liquid silicone is used. After placing the master model inside the casting box,
liquid silicone is poured all over it and allowed to cure in an oven. After cutting open the cured
liquid silicone mold, the master mold is removed, leaving an empty cavity. The empty hole is the same
shape and size as the original master pattern. Silicone molds can be reused 15-20 times.
Making the casting copies
To ensure that the mixture has the same properties as the industrial part, suitable resins (or
polyurethane similar to rubber) are mixed. The manufacturers have a list of material data sheets that
contain all of the information about the composition and properties of the casting materials. They use
that data to create a resin that closely resembles the properties of the master part. The mixture is
poured into the empty cavity to form the desired finished mold or product. The resin is then cured in a
vacuum to ensure that no air bubbles form.
Why vacuum casting method is preferred
Quick results
The vacuum casting process is rapid, and you can get a fixed volume of fully working models in almost
fewer days. So this process is ideal when deadlines have to be met or urgent orders need to be delivered
in fewer days. Clients can email their CAD model to the manufacturer and get the final product ready in
days
Reduced cost of production
Since silicone is a comparatively cheaper material and a single mold can be used for multiple prototypes,
the process is very economical compared to other traditional methods.
Better product quality
If you want to provide top-tier manufacturing services, your product quality must be exceptional. Not
only is the process fast in vacuum casting, but the final product is high quality and has better
structural properties, rigidity, and hardness. The final product has air pockets removed, which improves
its mechanical properties.
Better product finish
Since silicone is the mold material, the final product has an excellent finish and accurately resembles
the master pattern. Even the finest of details are captured in the finished product.
