Expanded Polystyrene Process
Uses a mold of sand packed around a polystyrene foam pattern which vaporizes when molten
metal is poured into mold
Other names: lost-foam process, lost pattern process, evaporative-foam process, and
full-mold process
Polystyrene foam pattern includes sprue, risers, gating system, and internal cores (if
needed)
Mold does not have to be opened into cope and drag sections