Kinetics of hardening and drying of ceramic moulds with the new generation binder – colloidal silica

The influence of selected factors on drying ceramic moulds applied in the investment casting technology was determined by the gravimetric method. Moulds produced of ceramic sands based on the new generation binders – colloidal silica, were investigated. It was found that each successive layer, of a similar thickness, is drying longer than the previous one. The drying time of layers forming closed spaces is several times longer as compared with drying open surfaces (external). Grain size of matrix used for moulds sprinkling has none significant influence on drying rates.