Method for the manufacture of molds using casting sand or another mixture of raw material particles

Abstract

In order to make casting sand or another moldable mixture, a pressure surge wave is used which has upper and lower limit values which values have been established by an optimal selection of a pattern of pressures. The other moldable mixture comprises particles of raw material, binder, water, and, if need be, additives. The rise in pressure takes place with an increasing pressure gradient, dp/dt, of at least 50 atmospheres (absolute)/second. A minimum pressure of at least 2 atmospheres (absolute) is maintained for at least 0.01 second. The pressure drop takes place at a decreasing pressure gradient,--dp/dt, of up to about 2.0 atmospheres (absolute)/second. The disclosed values represent an optimalization, in view of a simple design and economy of operation, with a surprisingly good compacting.

Dependencies are inferred from the claim text.