The production of thin-walled castings with wall thickness in the range of 1.5 to 3 mm and below requires the development of insulation

moulding sands and/or core materials. The test has been taken to develop these kind of materials. The study included a description of their

thermophysical properties. Authors described problems related to the heat flow in the casting-mould system, i.e. mathematically described

the main dependence of heat give-up during crystallization of the casting. The influence of the content of polyglicol on the thermophysical

properties of the mould with gypsum and cement binder was examined. Using the ATD method determined were the increments ΔT1 and

ΔT2 describing the temperature changes in the mould during crystallization of hypoeutectic alloy of AlSi6 and the temperature difference

between casting material and mould during the crystallization. In the considered range of technological parameters a description of the

heat flow kinetics was given.