The effects of moisture on the thermal protective performance of firefighter protective clothing under medium intensity radiant exposure

2017 ◽  
Vol 88 (8) ◽  
pp. 847-862 ◽  
Author(s):  
Hui Zhang ◽  
Guowen Song ◽  
Haitao Ren ◽  
Juan Cao
Keyword(s):  
Flame Retardant ◽  
Protective Clothing ◽  
Pearson Correlation ◽  
Outer Shell ◽  
Absorbed Energy ◽  
Thermal Protective Performance ◽  
Degree Burn ◽  
Firefighter Protective Clothing ◽  
Protective Performance ◽  
Second Degree

Current firefighter protective clothing is composed of multilayer fabric systems. The outer shell fabrics inevitably become wet in the process of firefighters performing their duties, and sweat may also increase moisture in the inner layers of protective clothing. In this study, two kinds of outer shell fabrics (aramid IIIA fabric and aramid 1313 and flame-retardant viscose-blended fabric) and two kinds of thermal liner fabrics with different thicknesses were selected. Three wetness conditions were simulated for the outer shell fabric, thermal liner fabric and both fabrics together. A modified thermal protective performance (TPP) tester was applied to assess TPP provided by these wetted fabrics; in addition, second-degree skin burn time was predicted and absorbed energy indexes were calculated. The regression method was employed to create fitting curves for absorbed energy and second-degree burn time in different configurations and the Pearson correlation was established to analyze their relationship, in which the lowest R2 value could reach 0.9122 and p-values were all much less than 0.05. Performance results for both wet conditions indicated that outer shell moisture and a thicker thermal liner have a positive and increased negative effect, respectively, on fabric TPP. When the sample S-3-D (aramid 1313 and flame-retardant viscose-blended fabric, moisture barrier and the thin thermal liner) was both wetted in the outer shell and thermal liner, its second-degree burn time was improved by 12.8% over performance in dry conditions. These findings may have important applications for the design and manufacture of optimal protective performance clothing systems.

Effect of moisture content on thermal protective performance of fabric assemblies by a stored energy approach under flash exposure

2017 ◽  
Vol 88 (16) ◽  
pp. 1847-1861 ◽  
Author(s):  
Hui Zhang ◽  
Guowen Song ◽  
Yiming Gu ◽  
Haitao Ren ◽  
Juan Cao
Keyword(s):  
Protective Clothing ◽  
Thermal Protection ◽  
Outer Shell ◽  
Absorbed Energy ◽  
Thermal Hazards ◽  
Thermal Protective Performance ◽  
Degree Burn ◽  
Protective Performance ◽  
Flash Exposure ◽  
Second Degree

Firefighters wearing protective clothing perspire profusely in the process of performing their duties, and sweat increases moisture in the inner layers of multilayer protective clothing. Also, the outer shell fabrics inevitably become wet. In this study, two kinds of outer shell fabrics (aramid IIIA fabric and aramid 1313 and flame-retardant viscose-blended fabric) and three kinds of thermal liner fabrics with different thicknesses were selected. Two wetness conditions were investigated to simulate the sweating in thermal liner fabric with or without the wet outer shell fabric. A modified thermal protective performance (TPP) tester was employed to explore the effects of moisture and its distribution on stored thermal energy developed in six fabric systems and on TPP under flash exposure. Pearson correlations were established to analyze the relationships of the fabric systems’ thickness and second-degree burn time, and of absorbed energy and second-degree burn time in different configurations. The statistical analysis from these obtained data indicated that the thickness of fabric systems had no significant correlation for second-degree burn time ( p > 0.05), but the absorbed energy exhibited a strong relation (the lowest R2 value could reach 0.8070 and p-values were all much less than 0.05). Performance results for the wet thermal liner indicated that the negative impact on thermal protection reached the greatest degree in 15% wetness, but in some extreme situations (100% wetness), the performance was improved (the maximum increase can achieve 116.2% over performance in dry condition). However, the existing moisture in the outer shell showed a positive effect. These findings will enable the engineering of textile materials that achieve high performance protection from thermal hazards and give some guidance to firefighters during operations.

scholarly journals Analysis of thermal properties, water vapor resistance and radiant heat transmission through different combinations of firefighter protective clothing

2019 ◽  
Vol 69 (06) ◽  
pp. 458-465
Author(s):  
NAEEM JAWAD ◽  
ADNAN MAZARI ◽  
AKCAGUN ENGIN ◽  
HAVELKA ANTONIN ◽  
KUS ZDENEK
Keyword(s):  
Heat Flux ◽  
Water Vapor ◽  
Flux Density ◽  
Heat Flux Density ◽  
Protective Clothing ◽  
Radiant Heat ◽  
Thermal Protective Performance ◽  
Firefighter Protective Clothing ◽  
Protective Performance ◽  
Different Levels

This experimental work is an effort to seek the possibility of improvement in thermal protective performance of firefighter protective clothing at different levels of heat flux density. Improvement in thermal protective performance means enhancement in the time of exposure against the heat flux, which will provide extra time to firefighters to perform their duties without suffering from severe injuries. Four different multilayer combinations of firefighter protective clothing were investigated. Each combination consists of outer shell, moisture barrier and thermal liner. Aerogel sheet was also employed as a substitute to thermal barrier. Initially, properties like thermal resistance, thermal conductivity, and water vapor resistance of multilayer fabric assemblies were investigated. Later on these combinations were exposed to different levels of radiant heat flux density i.e. at 10, 20 and 30 kW/m2 as per ISO 6942 standard. It was noted that those combinations in which aerogel blanket was used as thermal barrier acquire greater thermal resistance, water vapor resistance and have less transmitted heat flux density values.

Research on Thermal Protective Performance of Thermal Insulation and Flame-Retardant Protective Clothing

2013 ◽  
Vol 796 ◽  
pp. 607-612
Author(s):  
Fei Fei Li ◽  
Chun Qin Zheng ◽  
Guan Mei Qin ◽  
Xiao Hong Zhou
Keyword(s):  
High Temperature ◽  
Flame Retardant ◽  
Thermal Insulation ◽  
Protective Clothing ◽  
Thermal Protection ◽  
Single Layer ◽  
Woven Fabric ◽  
Standard Requirement ◽  
Thermal Protective Performance ◽  
Protective Performance

Thermal insulation and flame-retardant (TIFR) protective clothing, which has good thermal protective performance (TPP), could protect people from high-temperature or flame in casting industry, the petrochemical industry, fire industry and et al. That is, TIFR protective clothing must have certain function of slowing or restraining heat transmission, and insulating radiant heat and convection heat from high temperature heat source. The construction of TIFR protective clothing is being developed from single layer to multi-layer fabrics made by flame-retardant (FR) fibre. In this paper, based on TPP-206 tester, the TPP coefficient of single and multi-layer fabrics with flame-retardant were measured, and the TPP of TIFR protective clothing was analyzed. TPP coefficient of single fabrics included the FR viscose non-woven fabric do not meet the standard. That of all of multi-layer fabrics meet the standard requirement, and the FR viscose/wool blended fabric is not suitable for fire fighter. It is significant and the most observable effect to put the PTFE membrane between the outer layer and the insulating layer. It could improve the overall thermal protection performance.

scholarly journals Review: Radiation Heat Transfer Through Fire Fighter Protective Clothing

2017 ◽  
Vol 25 (0) ◽  
pp. 65-74 ◽  
Author(s):  
Jawad Naeem ◽  
Adnan Ahmed Mazari ◽  
Antonin Havelka
Keyword(s):  
Heat Flux ◽  
Thermal Insulation ◽  
Protective Clothing ◽  
Radiant Heat ◽  
Fire Fighter ◽  
Radiation Heat ◽  
Thermal Protective Performance ◽  
Firefighter Protective Clothing ◽  
Protective Performance ◽  
Different Levels

A fire fighter garment is multilayer protective clothing with an outer shell, moisture barrier and thermal barrier, respectively. Fire fighters encounter different levels of radiant heat flux while performing their duties. This review study acknowledges the importance and performance of fire fighter protective clothing when subjected to a low level of radiation heat flux as well as the influence of air gaps and their respective position on the thermal insulation behaviour of multilayer protective clothing. Thermal insulation plays a vital role in the thermal comfort and protective performance of fire fighter protective clothing (FFPC). The main emphasis of this study was to analyse the performance of FFPC under different levels of radiant heat flux and how the exposure time of fire fighters can be enhanced before acquiring burn injuries. The preliminary portion of this study deals with the modes of heat transportation within textile fabrics, the mechanism of thermal equilibrium of the human body and the thermal protective performance of firefighter protective clothing. The middle  portion is concerned with thermal insulation and prediction of the physiological load of  FFPC. The last section deals with numerical models of heat transmission through firefighter protective clothing assemblies and possible utility of aerogels and Phase Change Materials  (PCMs) for enhancing the thermal protective performance of FFPC.

Evaluation of Transfer Wicking Behavior of Fibrous Material Ensembles Used by Wildland Firefighters

2017 ◽  
Vol 730 ◽  
pp. 595-600 ◽  
Author(s):  
Hua Ling He ◽  
Zhi Cai Yu
Keyword(s):  
Water Content ◽  
Fibrous Material ◽  
Protective Clothing ◽  
High Performance ◽  
Air Permeability ◽  
Thermal Protective Performance ◽  
Firefighter Protective Clothing ◽  
Technical Basis ◽  
Protective Performance ◽  
Further Development

Moisture is widely recognized as one of the most important factors that influencing thermal comfort and thermal protective performance of firefighters. In this study, it was aimed to investigate the effect of liquid moisture on the transfer wicking behavior from the wet underwear fabric to the dry outerwear layer within two-layer fabric assemblies, which is typically used by wildland firefighters. The obtained results indicated that the transfer wicking behavior between the entire two-layer clothing systems selected is not very obvious. Results indicated that the transfer wicking ratio was low 5 percent of water content initially held in wet fabric. The greater amount of liquid water initially held in two-layer fabric assemblies, the greater the amount of water transferred. The effect of moisture level on air permeability of bi-layer fabric constructions associated with thermo-physiological comfort properties was also investigated. Results show that the air permeability of multilayer fabrics decreased with an increase of moisture content. Compared to having no water, the air permeability reduced to 50 percent when the water content reached up to 70%. The perception gained from this work could serve as technical basis for further development of high-performance firefighter protective clothing.

Relationship between Total Heat Loss and Thermal Protective Performance of Firefighter Protective Clothing and Consequent Influence on Burn Injury Prediction via Flame-Engulfment Manikin Test

2017 ◽  
Vol 61 (1) ◽  
pp. 1468-1471
Author(s):  
Jung-Hyun Kim ◽  
Do-Hee Kim ◽  
Joo-Young Lee ◽  
Aitor Coca
Keyword(s):  
United States ◽  
Heat Loss ◽  
Protective Clothing ◽  
Burn Injury ◽  
The United States ◽  
Total Heat Loss ◽  
Thermal Protective Performance ◽  
Injury Prediction ◽  
Firefighter Protective Clothing ◽  
Protective Performance

Firefighter protective clothing (FPC) provides barrier protection from hazardous materials. Two of the important performance factors tested for FPC are total heat loss (THL) and thermal protective performance (TPP). The present study evaluated the relationship between THL and TPP, and tested its subsequent influence on burn injury prediction via the flame-engulfment manikin test, using three FPC samples from the United States, Europe, and South Korea. The study results showed an inverse relationship between THL and TPP (r=-.949, p<.001). Predicted total area of second and third degree burn injury was 7.2±1.6, 19.7±4.1, and 5.0±1.0% for the United States, European, and South Korean FPC, respectively, which was significantly explained by both THL and TPP (F=34.630, p=0.001, R2=.920). The flame manikin test results showed that affected burn injury areas are not uniform over the body, but more frequent on the head and limbs.

Durability of Firefighters' Protective Clothing to Heat and Light

1988 ◽  
Vol 58 (3) ◽  
pp. 141-147 ◽  
Author(s):  
M. Day ◽  
J. D. Cooney ◽  
T. Suprunchuk
Keyword(s):  
Protective Clothing ◽  
Light Exposure ◽  
Heat Exposure ◽  
Outer Shell ◽  
Thermal Shrinkage ◽  
Flame Resistance ◽  
Thermal Protective Performance ◽  
Physical Strength ◽  
Protective Performance ◽  
Tearing Strength

Fabrics used in firefighters' protective clothing were exposed to simulated sunlight from a xenon are Weather-Ometer and heat in a forced air circulating oven, and the resulting changes in properties were measured (color, tearing strength, flame resistance and thermal protective performance). The thermal shrinkage and weight loss associated with heat exposure were also noted. Outer shell fabrics of Nomex III, Zirpro flame resistant wool, and PBI/Kevlar were all susceptible to light and underwent marked reductions in tensile tearing strength as a result of light exposure. Heat exposure resulted in a significant reduction in the tearing strength of all outer shell fabrics while increasing the tearing strength of moisture barrier fabrics. A polyamid/flame resistant viscose blend was extremely sensitive to heat exposure, undergoing a substantial loss in tearing strength and appreciable thermal shrinkage. Zirpro flame resistant wool was particularly sensitive to temperatures greater than 230°C. Although both light and heat caused losses in physical strength, there was no noticeable reduction in the flame resistance or thermal protective performance of the individual fabrics and garment assemblies studied.

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