Thermal protection retention of fire protective clothing after repeated flash fire exposure

Abstract

Fire protective clothing worn by the emergency responders may be exposed to intensive heat condition time and time again during a firefighting work. In this research, the level of thermal protection retained by the fire protective clothing after repeated exposures to flash fire was investigated from bench-scale test to full-scale test. A thermal protective performance tester and an instrumented manikin with a transverse motion system device which was capable of simulating the action of running across the flame were used for the exposure test. Physical properties (mass, thickness, thermal shrinkage, tear strength) and thermal protective property of the test specimens were examined after each exposure. The results showed that repeated heat exposures resulted in continuous decrease of mechanical performance of the fabrics. The thermal protective performance of fabrics with good thermal dimensional stability such as polybenzimidazole/Kevlar and flame resistant cotton decreased after exposure. For the fabrics with severe thermal shrinkage such as Nomex IIIA and polysulfonamide, the thermal protective performance was improved due to the increase of fabric thickness induced by thermal shrinkage. However, this positive effect of thermal shrinkage diminished in the manikin test as it decreased the air gap size between the garment and flame manikin. The thermal protective property of Nomex IIIA garment exhibited continuous decrease after repeated exposures. This study was expected to provide new sights for the performance evaluation and application of fire protective clothing.

Characterization and Modeling of Thermal Protective and Thermo-Physiological Comfort Performance of Polymeric Textile Materials—A Review

“…In the future, thermal protective performance could be evaluated in consideration with the attenuation factors and empirical models could be developed for properly predicting the thermal protective performance of fabrics. Moreover, Wang and Li (2015) [73] found that repeated flame exposure to fabric samples continuously reduce the thermal protective performance of the fabrics depending upon the polymeric fibers used in the fabrics. This thermal protective performance also was significantly affected by the shrinkage of the fabrics under flame exposure [74].…”

“…Wang and Li (2016) [73] Repeated flame exposure could reduce the thermal protective performance depending on the types of fibers used in the fabrics.…”

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

“…Research based on full-scale manikin tests revealed that garment shrinkage during exposure could greatly reduce the air gap and potentially cause a significant decrease in the performance of thermal-protective clothing [33,43]. Surface area changes could represent the thermal shrinkage of the fire-retardant fabrics [44]. A higher surface area retention indicated better thermal stability of the fabrics.…”

The Effect of Air Gap and Moisture for the Skin Burn Injury of the Firefighter’s Personal Protective Clothing (PPC)

“…The air possess good thermal insulator as it's material thermal conductivity is less than the fabrics [16]. The air gap can significantly improve as the air gap reached 6.4mm thickness between fabric and the sensor [17]. The air gap thickness that located between the fabric and skin layer the thickness varies at each of body location [15].…”