Characterizing the Heat Transfer Performance of Contaminated Flame-Resistant Fabrics

Abstract

For the safety of workers in the oil and gas field, flame-resistant clothing is recommended to reduce the risks of skin burns and fatalities resulting from heat and fire hazards. However, flame-resistant fabrics (FRFs) contaminated with flammable substances can compromise their flammability and heat transfer properties. Therefore, this study aims to evaluate the heat transfer performance (HTP) of the contaminated FRFs to improve workers' safety from burn injuries by understanding how contamination affects fabric thermal protection. The HTP in terms of second-degree burn time was evaluated and characterized by exposing the fabrics to 84 kW/m² mixed convective and radiant heat flux. The peak temperature and average heat release rate of the FRFs were also evaluated. Two levels of contamination, consisting of drilling mud and crude oil, were added to three FRFs: Meta-aramid/cotton, meta-aramid/para-aramid, and para-aramid/polybenzimidazole. The HTP of drilling mud-contaminated fabrics increased, while the HTP of crude oil-contaminated fabrics varied by fabric type and contamination level. This may be attributed to drilling mud's higher specific heat capacity and lower flammability than crude oil. Among the fabrics tested, meta-aramid/cotton fabric showed the best HTP with higher second-degree burn times of 9.63 s with drilling mud and 9.07 s with crude oil. The relationship among contamination level, fabric properties, and HTP was developed using a multiple linear regression statistical model. The fabric's properties, such as fabric weight and air permeability, significantly contributed to the HTP of the contaminated fabrics.