Highly porous carbon moulding core prodn. - by moulding mixt. of porous carbon powder and binder in core mould and heating to cure binder

摘要

In the prodn. of a moulding core from C with a pore vol. of min. 80%, C particles with a pore vol. of min. 80% are mixed with a curable binder, the mixt. is moulded in a core mould and the binder is cured by heating the mould. Pref. the C particles used are ground foamed C, hollow C beads or activated charcoal. Pref. the binder is phenol-HCHO or furan resin and is used in an amt. of max. 1%. It is not necessary to machine the core by turning and even cores of complex shape can be made without loss of material. In use, the core material can be removed from the casting by burning the C, which takes only fractions of a minute if an O2 lance is used for combustion.