Method and system for drying casting molds

A method for drying casting molds comprising:

• providing a casting mold comprised of a meltable pattern coated with a ceramic slurry containing a liquid solvent and a binder;
• placing the casting mold in a chamber;
• encapsulating the casting mold in a desiccant material;
• sealing the chamber sufficient to pull a vacuum in the chamber;
• applying a variable vacuum to the chamber, the vacuum being controlled so that the vacuum gradually increases from atmospheric pressure to a maximum vacuum pressure such that the meltable pattern has a temperature that does not decrease more than 5 degrees F. from atmospheric pressure to maximum vacuum pressure.

A method for forming and drying an investment casting mold comprising:

• providing a wax pattern of a metal part to be cast;
• applying a ceramic slurry coating to the pattern containing a liquid solvent to define a wet casting mold;
• encapsulating the casting mold with a desiccant material;
• applying a vacuum to the casting mold for a total vacuum time measured from atmospheric pressure to a maximum vacuum pressure, wherein the vacuum is applied at a rate such that approximately 24% of the total vacuum time is used to increase the vacuum by approximately 75% and such that the wax pattern has a temperature that does not decrease more than 5 degrees F. from atmospheric pressure to maximum vacuum pressure.

A method for forming and drying an investment casting mold comprising:

• providing a meltable wax pattern of a metal part to be cast;
• applying a ceramic slurry coating to the pattern containing a liquid solvent to form a wet casting mold;
• fluidizing a bed of unheated desiccant at ambient room temperature;
• immersing the casting mold in the bed of desiccant;
• drying the casting mold by applying a controlled variable vacuum to the casting mold over a period of time, the vacuum being controlled to gradually increase from atmospheric pressure to a maximum vacuum pressure such that the wax pattern maintains a temperature that does not decrease more than 5 degrees F. from the temperature of the pattern at atmospheric pressure.