Inverse estimation of the temperature-dependent thermophysical properties of a flame-retardant fabric and thermal performance analysis

The present study estimates temperature-dependent thermophysical properties of Teijin Conex fabric using an inverse heat transfer–based parameter estimation approach. The SNOPT algorithm is employed to predict specific heat and thermal conductivity using the benchtop experimental data. These estimated properties are subsequently used to analyze the thermal behavior of a protective clothing system comprising the fabric, an air gap, and human skin using a transient coupled conduction–radiation model. Temporal and spatial temperature distributions within the fabric and skin are evaluated. Pronounced temperature gradients in the fabric during exposure highlight its thermal insulation, while the air gap provides additional protection. During cooldown, the air-gap temperature continues to rise, potentially increasing post-exposure burn risk. Thermal damage analysis indicates no burn injury for the single-layer fabric considered. These findings provide quantitative insight into the protective performance of flame-retardant fabrics under transient thermal exposure.