Bentonite is clay rock, which is created by decomposition of vulcanic glass. It is formed from mixture of clay minerals of smectite group,
mainly montmorillonite, beidellite and nontronite. Its typical characteristics is, that when in contact with water, it intensively swells. First
who used this term was W.C. Knight in 1887. The rock had been named after town Fort Benton in American state Montana. For its
interesting technological properties and whiteness has wide technological use. Bentonite is selectively mined and according to its final use
separately modified, which results in high quality product with specific parameters.
In the beginning of 21st century belong bentonite moulding mixtures in foundry to always perspective. Mainly increased ratio of ductile
cast iron castings production cannot be ensured without the need of quality bentonite. Great area of scope remains to further research of
moulding materials, which return also to bentonite producers.
This paper deals with production of safety inlay for steam locomotive valve by the Patternless Process method. For the moulds creation was used moulding mixtures of II. generation, whereas binder was used a water glass. CNC miller was used for creation of mould cavity. Core was created also by milling into block made of moulding compound. In this article will be presented also making of 3D model, setting of milling tool paths and parameters for milling.