V-Process Molding and Casting

The vacuum-sealed molding process (aka V-Process) allows molders to make complex molds using dry, unbonded and freely flowing sand.  Molds are sealed by using plastic films along the top and bottom sand surfaces of the cope and the drag molds and then vacuum applied to the sand media of the cope and the drag.  The plastic film along the top of the drag mold and the bottom of the cope mold is softened by heating and then formed on an appropriate pattern to produce the hollow cavity for the final casting  in the finished mold.  Note in the picture below from Auburn University's casting laboratory that the sand is being held in the elevated cope mold only by the atmospheric pressure against the sand.