1. Special pouring method
It is important to note that no bubbles are formed when the silicone rubber is poured into molds and models. A small amount of rubber is poured into the mold box and the inclination angle is tilted to ensure that the rubber flows to the entire surface. Wet the surface of the model with a thin layer of rubber and remove air bubbles with a paintbrush.
2. Apply compressed air to the silicone mold
After the first round of rubber is poured into the mold box, the material is blown onto the model using an air compressor to wet the surface, and the first layer of the film should be free of bubbles.
3. Remove the air from the silicone mold with a vacuum
The formation of air bubbles is due to the trapping of air during the mixing process. Stir the mixture slowly and steadily, but there will still be air left in the mixture. They will be removed with the help of a vacuum chamber.
4. Use pressure to force air into the solution
Air is pressed into a pressure vessel by molding a rubber mixture, and the air pressure is pressed against the material, which extrudes the bubbles. Obtain a pressure vessel that fits into the mold box and check that the setting time of the rubber mold has been set. The mixture is poured into a mold box inside the model, and the sealed pressure vessel is set to 60-100psi, this technique works well in rubber mold making if the mold making material settles while the vessel is under pressure.
5. Make the perfect master or design
There are two ways to get the perfect model or design for Vacuum casting: one method to consider is CNC technology. This provides the highest precision parts with tight tolerances of /- 0.05mm. However, unlike SLAs, the processing time is longer. Another approach is SLA. Especially for complex designs, it is faster and can also be easily combined with all internal 3D and CAD import functions.