Compactability and permeability control for fabricating ecp mold

Abstract From the Canadian patent

17-, Abstract, A method of controlling during the act of mold, fabrication in real time the compactability and, permeability of a sand mold containing an evaporative foam pattern, comprising: (a) while agitating a supply of loose, unbonded sand introduced about such pattern suspended in a flask, supplying a pressurized gas to one station of the sand while permitting the gas to exit from another station of such sand supply; and (b) proportionally measuring the pressure differential between such stations thereby rendering a proportional indicator of sand compaction. Agitation is preferably carried out in stages, the first stage of which comprises agitation by vibration at a rate to migrate …