Abstract: A method for making foundry moulds and cores where after preparation of the moulds and cores having a sand composition of a low strength up to 0.03 MPa, a cooling medium is introduced into the mould cavity, preferably liquid nitrogen, in an amount to provide hardening of only the surface layer of a required sufficient to reproduce the shape of the mould cavity.

Abstract: Apparatus for making shells from thermosetting liquid compounds in which at a first station, a travelling and heated permanent metal mould becomes filled with a thermosetting liquid compound. The mould is then moved to a second station where it is held until a shell wall of desired thickness is obtained. Thereafter, the mould is transferred to a further station where excess thermosetting compound is recovered and dispensed to an accumulative mixer to be used again. Subsequently, the metal mould is passed to a final station where it is opened and the ready shell removed. The apparatus comprises said and liquid constituent containers, a sand feeder and two mixers, namely, a basic mixer and an accumulative mixer. The apparatus is provided with a unit for proportioning the liquid constituents and a delivery unit to force the compound into the mould.