How to create a helmet mold?

Lay the pre impregnated material layer by layer on the model.
Apply release agent to the model, and then place the pre impregnated model into the mold cavity.
Insert silicone airbags into the model and inflate them to compress the model inside the mold.
Apply pressure at a high temperature of 150 degrees and hold for more than 20 minutes before opening the mold.