GB1475069A - Manufacturing a foundry mould or core - Google Patents

Abstract

1475069 Moulding foundry moulds and cores WEST OF ENGLAND SECURITIES Ltd 3 Sept 1974 [5 July 1973] 32017/73 Heading B3G A method of producing a foundry mould or core comprises electrostatically depositing a particulate material comprising ceramic powder on to a pattern or core box, aggregating the layer thus formed, and removing the mould or core from the pattern or core box. The particulate material may include epoxy resin as a bonding agent, in which case the deposited layer is aggregated by infra-red heating, or a bonding agent which is hardened by exposure to carbon dioxide gas may be used. Fig. 2 shows an apparatus for the continuous production of moulds such as that shown in Fig. 1. Patterns 1 are fed to a rotatable disc 2 at a loading station 3, indexed to a first deposition station 4 where a first layer 13, of ceramic powder and epoxy resin, is electrostatically sprayed on to the pattern, indexed to a curing station 5 having infra-red heaters 14 where the epoxy resin is hardened, through further spraying and curing stations 6, 7, 8, 9 where the layers 15, 16 are formed, and on to a filling and packing station 10 where a box 17 is positioned around the pattern and filled with a backing 18 of coarse refractory. The layers 15, 16 comprise a coarser ceramic material than the first layer 13. At an unloading station 11, the pattern and mould are removed. If the pattern is fixed to the disc, loading station 3 is omitted and an additional station provided for coating the pattern with mould release after removal of the mould at 11. In Fig. 3 (not shown), a core is produced by depositing particulate material from an electrostatic spray gun into a split core box. In this case, the most convenient method of aggregating the deposited layer is by use of a CO 2 - hardenable bonding agent, CO 2 being passed into the core through a pipe. The continuous apparatus described above may be used in conjunction with core boxes.