Fig. 4 – Dip or Invest
STEP 4:
Using our multi-axis robot, the tree is dipped into one of a series of ceramic slurries. Each slurry is made from a water based colloidal silica, with various types and consistencies of ceramic powders added to form the high grade ceramic. The dipping of the wax tree into the slurry is also called investing the tree, and is where the term “investment casting” originated. This is intended to differentiate this precision casting process from “solid mold” precision ceramic mold casting, which also uses ceramic slurry, but rather than building a thin shell, the wax pattern is encased in a solid mass of ceramic. Dental appliance manufacturers and jewellery manufacturers use solid mold casting, where industrial precision casting uses shell molding almost exclusively due to its ability to be more geared to production at lower costs.