A new approach for evaluating the thermal performance of flame-resistant fabrics

Abstract

Flame-resistant clothing or fabrics against thermal exposure is a crucial requirement in order to ensure people survivability and to protect the structure. A model-based method was developed to evaluate the thermal performance of flame-resistant fabrics used in protective clothing. The skin simulant sensor is used to determine the heat flux at the skin simulant surface from the elevation of temperature of the skin simulant surface. The heat flux is then applied to a newly developed skin thermal wave model (STWM) instead of Pennes' model, which inherits some questionable physical and physiological aspects, and the Henriques burn integral is incorporated into the new model to predict the level of skin injury. Results of tolerance time from the Stoll criterion method are also compared with those from the Henriques method with two skin models (Pennes' model and STWM) by a thermal protective performance calorimeter. Deviations between the STWM and the traditional Pennes' equation imply that the STWM, which accounts for finite thermal wave propagation, may provide realistic predictions on burn evaluation. The comparison measurements show that the test results by the STWM correlated well with those obtained from the Henriques method with Pennes' model. Therefore, this test method provides a new technique to accurately and precisely characterize the thermal performance of flame-resistant fabrics.