Vacuum Casting Process
|Step 1:Master building||Masters are 3D solids of your CAD designs. They are usually made by CNC machining or with 3D Printing. Making Master in 40° temperature. After finish and inspect the masters, we will move to silicone mold making.|
|Step 2: Mold making||Casting molds are made from liquid silicone. Half-Fill the casting box with liquid silicone, Heat the casting box until silicone is fully cured and then allowed to cure in an oven for 16 hours. Fill with extra silicone liquid which is also heated & cured. Once dried, the mold is cut open and the master removed.|
|Step 3: Make the parts||Poured the casting resins into the empty cavity to create a highly accurate copy of the original. It’s even possible to overmold with two or more materials. Silicone molds are typically good for 20 or so copies of the master pattern.|
Vacuum Casting Technical Specifications
|Typical lead time||Up to 20 parts in 15 days or less, depends on the part specification and volumes.|
|Accurate||± 0.3% (with lower limit on ± 0.3 mm on dimensions smaller than 100 mm)|
|Minimum wall thickness||To ensure that the mold is filled properly, a wall thickness of at least 0.75 mm is necessary. For best results, we recommend a wall thickness of at least 1.5 mm|
|Maximum part dimensions||The size of the mold is limited by the dimensions of the vacuum chamber (1900 x 900 x 750 mm) and by the volume of the product (maximum volume: 10 liters)|
|Typical quantities||Up to 25 copies per mold (depending on the mold’s complexity and the casting materials)|
|Color & Finishing||Pigment is added to the liquid polyurethane prior to casting, custom painting and texture.|
Vacuum Casting FAQ
Why would I choose vacuum casting over injection molding?
Vacuum casting is a more affordable alternative to IM, especially in low volumes. It also offers unique advantages like an excellent surface finish.
Can I make production-quality parts using vacuum casting?
Vacuum casting is best for making visually impressive prototypes, but it can also be used for non-mechanical end-use parts like cases and covers.
What happens to the silicone mold(s)? Can I keep them?
The silicone molds used in vacuum casting have a short lifespan, typically around 20 moldings, so we dispose of them after use.
If you wish to keep the 3D printed or CNC machined master model, talk to us directly.