1.    Make a solid master model that should be able to withstand a temperature of 40° C.
2.  Suspend this master model inside of a casting box, which we half-fill with liquid silicone rubber. 
3.  Place the box inside of a curing oven until the silicone is fully cured.
4.  Fill the casting box with additional silicone liquid which is also heated and cured. 
5.   Open up the silicone rubber mold along the parting line and remove the master, a hollow cavity left.
6.   Place a series of fine holes surrounding the master pattern.
7.   Fill the cavity with any number of molding polymers to suit your design requirements.  ​
8.   Place them into a vacuum chamber which draws air out of the cavity and pulls the liquid plastic into all of the recesses of the mold.
9.  Put the mold into a curing oven one more time, creating a solid and stable replica of your original master pattern.