The Function of Colloidal Silica

Colloidal silica serves two functions in the process. Since it is a low viscosity water-based liquid it is used as the vehicle to slurry the ceramic powders which make up the ceramic shell. The viscosities of slurries used in the process are usually similar to a thin crepe or pancake batter. They must be thin enough to flow into the surface details of the wax patterns such as the narrow grooves in a golf club head, but thick enough to leave a continuous 

Injection Molding of wax allows multiple patterns to be produced quickly and uniformly. 

FIGURE 12.37 Modem shell investment casting pattern production. 

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