The solvent is removed, and the part is heated to burn out the polymer. Finally, the part is fired to produce the ceramic. The process is capable of making very complex parts such as turbine wheels. Some shapes made with this technique cannot be made any other way. A major drawback to the original gelcasting technology was its reliance on acrylamide as the gelling additive.
Acrylamide is highly sensitive to oxygen, which inhibits polymerization.
So the process must be done in an inert environment, which raises the cost. Acrylamide gel is also very difficult to remove if an inert environment is used, raising costs even more. Most important, however, acrylamide is a cumulative neurotoxin, and safety concerns had prevented the technology's widespread use. AlliedSignal's innovation in this ATP project was to develop a low-cost, nontoxic alternative that retains acrylamide's excellent process characteristics. In addition, the new gelcasting process has potential applications in energy, chemicals, aerospace, electronics, advanced materials and telecommunications.