Quantitatively evaluating the effects of flash fire exposure on the mechanical performance of thermal protective clothing

Abstract

Purpose The purpose of this paper is to determine the effect of flash fire exposure on the mechanical properties of single-layer thermal protective clothing. Design/methodology/approach The full-scale flame manikin tests were performed to simulate flash fire exposure. Two typical fire-resistant fabrics were investigated. The manikin was divided into seven body parts and the specimens meeting the requirements of tensile and tear strength standards were sampled. Fabric thickness, mass per unit area, tensile strength and tear strength were measured and analyzed. Findings The results revealed the significant influence of heat flux on both of tensile and tear strength. However, the regression analysis indicated the low R2 of the liner models. When the tensile and tear strength retention were reorganized based on the body parts, both of the multiple linear regression models for tensile and tear strength showed higher R2 than the one-variable linear regressions. Furthermore, the R2 of the multiple linear regression model for tear strength retention was remarkably higher than that of the tensile strength. Practical implications The findings suggested that greater attention should be paid to the local part of human body and more factors such as the air gap should be considered in the future thermal aging of firefighters’ clothing studies. Originality/value The outcomes provided useful information to evaluate the mechanical properties of thermal protective clothing and predict its service life.

Characterizing the Tensile Strength of the Fabrics Used in Firefighters’ Bunker Gear under Radiant Heat Exposure

“…The effects of flash fire on the mechanical properties of single layer thermal protective fabrics have been examined [19]. Similar kinds of results were found; the heat flux significantly affected the mechanical properties of the thermal protective fabrics [19].…”

“…However, the thermal protective performance did not change considerably as a consequence of changes in the mechanical properties [8]. The effects of flash fire on the mechanical properties of single layer thermal protective fabrics have been examined [19]. Similar kinds of results were found; the heat flux significantly affected the mechanical properties of the thermal protective fabrics [19].…”

“…The effects of repeated exposure to heat of personal protective gear have often been studied [7,8,[19][20][21][22]. Variables included intensity of heat flux, time, and frequency of exposure, among others.…”

“…This ultimately could contribute to the causes of injury to firefighters. The change of strength of the fabrics used in bunker gear due to radiant heat exposure has been extensively examined [7,8,[19][20][21][23][24][25][26][27][28][29][30]. However, a determination of strength loss of the outer layer after being exposed to heat when the fabric is in moist condition has not been carried out.…”

Investigating the Thermal-Protective Performance of Fire-Retardant Fabrics Considering Garment Aperture Structures Exposed to Flames

“…The thermal aging of Kevlar/PBI blends was attributed to the change of a crystallite size crystalline lattice of Kevlar and random chain scissions of PBI [55]. A full-scale flame manikin study revealed the complicated effects of garment structure on thermal degradation of thermal-protective clothing [56]. Numeric simulation also indicated that the heat transfer in the air space was more complicated on the garment level than the fabric, because of the varying relative positions between different body segments and the heat source, as well as the ventilation openings [57].…”