Apparent thermal conductivity of PAN-based carbon fibre tow based on infrared thermography measurements

•We proposed the applications of infrared thermography to calculate the apparent thermal conductivity of CF tow using Fourier’s law of conduction.•With direct electrical heating of CF tow, the infrared thermal imaging was employed to measure the heat radiation from the surface of CF tow.•The estimated average thermal conductivity of PAN-based 12 K CF tow was about 21.28 W/m·K. Currently, the apparent thermal conductivity of carbon fibre (CF) is measured using contact- and noncontact-type thermal conductivity methods. The contact-type method exhibits measurement non-uniformity in the CF thickness direction that does not allow uniform sampling; the error occurrence rate is known to be high. Meanwhile, in the noncontact-type method, the fibre porosity and tow gap results in a lower accuracy and similarly high error occurrence rate. Therefore, this study aims to provide a quantitative method of measuring the thermal conductivity of polyacrylonitrile (PAN)-based 12 K CF tows with a filament diameter of 7 µm using Fourier’s law of conduction and a thermal imaging camera. This method is expected to overcome the limitations of the conventional contact- and noncontact-type techniques. Using the proposed method, the average thermal conductivity of the PAN-based 12 K CF tow was measured to be approximately 21.28 W/m·K.