Abstract
Commercial MIM processes use thermal debinding and solvent debinding; the former requires a long debinding time, while the latter involves the use of toxic solvents. We have been investigating the application of supercritical CO2 extraction method to debinding process, which promises to overcome these drawbacks. For actual application of this process, we need to overcome two problems. The first one is that the process requires the high-cost pressure vessels, and the second one is low solubility of binders in supercritical CO2. In the process developed by Takishima and others, the latter problem is resolved by using of activated carbon as an adsorbent; this method is efficient and fast but introduces the additional problem that used activated carbon becomes waste. Here we propose the use of a liquid solvent as an adsorbent. This method allows easier treating of the adsorbent and higher binder extraction. The dissolved binder can be re-extracted from the adsorbent by distillation. Moreover, the extraction pressure can be decreased with using this method, and the cost for the pressure vessel can be reduced.
