Moulding material related studies within research activities concerning foundry technology have always been limited, despite the significant effect of moulding mixtures on the quality of cast parts. One reason behind this trend is the difficulty in interpreting results of such complex systems like moulds and cores. This paper provides a new possibility to study the heat absorption performance of materials used as moulding media in metal casting processes. By further developing the Fourier thermal analysis method of cores and moulds introduced by earlier authors, the investigation of unbonded sand has become available. Heat absorption properties of the components can be hereby separated and studied respectively. Thermal analyses were performed on sphere shaped, resin bonded cores with various binder levels and on unbonded sand samples. The temperature data collected in two points of the samples were then used for the calculation of novel thermophysical properties. The results revealed not only quantitative but qualitative differences in the characteristics of binder decomposition processes, providing deeper understanding on the thermal behavior of moulding materials. The outcome of the research provides more accurate data, which is the key for improved simulation of casting processes.