Due to the high cost of energy, thermal properties of textiles are considered optimum to prevent energy loss. Nonwoven tissues include fibrous materials can be used for thermal insulation application. Thermal properties of porous materials are provided by internal pores. Nonwovens due to its good insulation can be simulated. Many factors may affect thermal properties. The purpose of this work is to investigate the effect of structural parameters on heat transfer properties. In this study, the effect of mean fibre orientation and porosity of nonwoven fabric on thermal conductivity were studied. For this purpose, the needle punched samples with punch densities of 90, 110, 120, 135 and 150 Punch per cm² and depth of needle penetration to 10, 13, 15, 17 and 19 mm were constructed. The mean fibre orientation angle of the fabrics was calculated by fast Fourier transform method. The thermal conductivity of the samples was calculated using a guarded hot plate device. Multiple regressions based on least square method were used to investigate the results. The results of this work show that porosity has more significant effect of thermal conductivity of nonwoven in comparison the Mean fibre orientation.
