Studies of the thermal protective performance of fabrics under fire exposure: from small-scale to hexagon tests

2017 ◽  
Vol 88 (20) ◽  
pp. 2339-2352 ◽  
Author(s):  
Sumit Mandal ◽  
Simon Annaheim ◽  
Thomas Pitts ◽  
Martin Camenzind ◽  
René M Rossi

This study aims to investigate the thermal protective performance of fabrics used in firefighters' clothing under high-intensity fire exposure. The performance of thermal protective fabric systems with different physical properties was evaluated under laboratory simulated fire exposure. Additionally, the influence of the configuration of the fire exposure tests and modes of heat transfer through the fabrics was also thoroughly investigated. The protective performance was evaluated using the standard small-scale flame [International Organization for Standardization (ISO) 9151:1995] and radiant heat (ISO 6942:2002) exposure tests. Additionally, the protective performance was evaluated under flash-fire exposure using a newly developed hexagon test. The protective performance values obtained from the small-scale (flame and radiant heat) and hexagon (flash fire) tests were compared and discussed. It has been found that a multi-layered fabric with high weight, thickness, and thermal resistance can significantly and positively affect the protective performance. If the air permeability of this fabric is high, it can show a lower protective performance; however, the impact of air permeability on the protective performance is insignificant especially in the case of the hexagon test. Notably, the protective performance can differ under two types of small-scale tests − flame and radiant heat. Also, this protective performance value is generally higher in the case of hexagon test in comparison with the small-scale tests. These differences in protective performance are mainly due to the unique configurations of these tests and/or different modes of heat transfer through the tested fabrics. The findings from this study will guide textile or materials engineers in the design and selection of materials for high performance thermal protective clothing; in turn, it will improve the occupational health and safety for firefighters.

2017 ◽  
Vol 730 ◽  
pp. 595-600 ◽  
Author(s):  
Hua Ling He ◽  
Zhi Cai Yu

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.


Author(s):  
Frazier Hull ◽  
Jett Gambill ◽  
Andrew Hansche ◽  
Gian Agni ◽  
John Evangelista ◽  
...  

This paper presents a continuation of projects spanning the last two years. In year one, the physical characteristics and medical effects of burns and Improvised Explosive Device, IED, blasts were investigated [1]. In year two, the possible use of commercial intumescent materials with fabric was studied [2]. The identified needs for research into the effect of undergarments on burn protection are focused in this study. Additionally, Thermal Protective Performance, TPP-(ISO 17492) and Air Permeability, AP-(ASTM D737) tests were performed to gather the data needed for the analysis of flame and thermal resistance as well as comfort and breathability. Out of the seven samples evaluated, the Sample D, composed of 94% m-aramid, 5% p-aramid and 1% static dissipative fiber, shirt had the best overall performance in terms of air permeability, average TPP rating, and time to second degree burn. Another finding was that polyester undershirts may be dangerous in the event of a flash fire situation because the fabric could melt and stick to the Soldier’s skin causing more severe burn injury. Additionally, an initial framework for a basic mathematical model representing the system was created. This model can be further refined to yield more accurate results and eventually be used to help predict the material properties required in fabrics to design a more protective undergarment.


Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 525
Author(s):  
Ana Kiš ◽  
Snježana Brnada ◽  
Stana Kovačević

In this work, aramid fibers were used to develop new, high-performance fabrics for high-temperature protective clothing. The research was based on the impact of the weave structure on fabric resistance to radiant heat. The goals of the research were primarily related to the development of new fabric structures created by the weave structure, which gives better protection of the body against high temperatures in relation to the standard weave structures that are used today. According to the results obtained it can be concluded that the fabric weave significantly affects the fabric structure, which consequently determines the effectiveness of protection against high temperatures. The justification for the use of multi-weft and strucks weave structure, which provides greater thermal protection and satisfactory breathability than commonly used weave structures, was ascertained.


2018 ◽  
Vol 89 (16) ◽  
pp. 3244-3259 ◽  
Author(s):  
Sumit Mandal ◽  
Simon Annaheim ◽  
Andre Capt ◽  
Jemma Greve ◽  
Martin Camenzind ◽  
...  

Fabric systems used in firefighters' thermal protective clothing should offer optimal thermal protective and thermo-physiological comfort performances. However, fabric systems that have very high thermal protective performance have very low thermo-physiological comfort performance. As these performances are inversely related, a categorization tool based on these two performances can help to find the best balance between them. Thus, this study is aimed at developing a tool for categorizing fabric systems used in protective clothing. For this, a set of commercially available fabric systems were evaluated and categorized. The thermal protective and thermo-physiological comfort performances were measured by standard tests and indexed into a normalized scale between 0 (low performance) and 1 (high performance). The indices dataset was first divided into three clusters by using the k-means algorithm. Here, each cluster had a centroid representing a typical Thermal Protective Performance Index (TPPI) value and a typical Thermo-physiological Comfort Performance Index (TCPI) value. By using the ISO 11612:2015 and EN 469:2014 guidelines related to the TPPI requirements, the clustered fabric systems were divided into two groups: Group 1 (high thermal protective performance-based fabric systems) and Group 2 (low thermal protective performance-based fabric systems). The fabric systems in each of these TPPI groups were further categorized based on the typical TCPI values obtained from the k-means clustering algorithm. In this study, these categorized fabric systems showed either high or low thermal protective performance with low, medium, or high thermo-physiological comfort performance. Finally, a tool for using these categorized fabric systems was prepared and presented graphically. The allocations of the fabric systems within the categorization tool have been verified based on their properties (e.g., thermal resistance, weight, evaporative resistance) and construction parameters (e.g., woven, nonwoven, layers), which significantly affect the performance. In this way, we identified key characteristics among the categorized fabric systems which can be used to upgrade or develop high-performance fabric systems. Overall, the categorization tool developed in this study could help clothing manufacturers or textile engineers select and/or develop appropriate fabric systems with maximum thermal protective performance and thermo-physiological comfort performance. Thermal protective clothing manufactured using this type of newly developed fabric system could provide better occupational health and safety for firefighters.


2017 ◽  
Vol 21 (4) ◽  
pp. 1665-1671 ◽  
Author(s):  
Meng Chen ◽  
Fanglong Zhu ◽  
Qianqian Feng ◽  
Kejing Li ◽  
Rangtong Liu

The effects of absorbed moisture on thermal protective performance of fire-fighters? clothing materials under radiant heat flux conditions were analyzed in this paper. A thermal protective performance tester and temperature sensor were used to measure the temperature variations for the facecloth side of four kinds of commonly used flame retardant fabrics in several radiant heat exposures, which varied in moisture content. Experimental results showed that, all of the temperature profiles of these four kinds of moistened fabrics under different radiant heat flux conditions presented the same variation trend. The addition of moisture had a positive influence on the thermal protective performance during the constant temperature period when heat radiation time was more than 60 seconds. As the heat radiation time increased beyond 500 seconds, the thermal protective performance of moistened fabrics became worse than that of dried fabrics in general.


2013 ◽  
Vol 821-822 ◽  
pp. 233-236
Author(s):  
Xiao Hui Li ◽  
Min Wang ◽  
Jun Li

Objective and quantitative evaluation of garment thermal protective performance should be based on the simulation of human in actual thermal environments as realistic as possible. In this paper, by using a new type of flame manikin which can rotate and make different postures, the dynamic scene where a firefighter wearing fire protective ensembles rescue in the flash fire was simulated. The skin burn prediction result showed that the total burn percent suffered by the manikin was 7.76%, of which the 2nd degree burn and the 3rd degree burn was 5.12% and 2.64% respectively. This indicated that the firefighter ensembles exhibited relatively good thermal protective performance. It can provide enough protection for the firefighter in 8s dynamic exposure while more protection should be added to the head.


2004 ◽  
Vol 74 (12) ◽  
pp. 1033-1040 ◽  
Author(s):  
Guowen Song ◽  
Roger L. Barker ◽  
Hechmi Hamouda ◽  
Andrey V. Kuznetsov ◽  
Patirop Chitrphiromsri ◽  
...  

2002 ◽  
Vol 29 (1) ◽  
pp. 377-384 ◽  
Author(s):  
J. Richard ◽  
J.P. Garo ◽  
J.M. Souil ◽  
J.P. Vantelon ◽  
D. Lemonnier

Author(s):  
Amina Radhouane ◽  
Nejla Mahjoub ◽  
Hatem Mhiri ◽  
George Lepalec ◽  
Philippe Bournot

“Twin jets in Crossflow” is a common configuration that finds application in several large and/or small scale industrial fields. The interest in such a configuration is further enhanced by its dependence in several parameters, that may be geometric, dynamic, thermal, or relative to the handled fluid composition. We propose to focus in the present work on the effect of the number of the emitted jets on the generated heat transfer, in presence of an unchanged uniform crossflow. To reach this goal, single, double and triple jet configurations were simulated, based upon the resolution of the Navier Stokes equations by means of the RSM (Reynolds Stress Model) second order turbulent closure model, together with a non uniform grid system particularly tightened near the emitting nozzles. After validation, we tried to find out the impact of the number of the handled jets on their cooling “power” by tracking the temperature distribution of the resulting flowfield. Since in practically all applications we are in need of higher efficiencies and then of higher operating temperatures, we are constantly concerned about not going beyond the shielding material melting temperature. If the use of cooling jets proves to be efficient, this may bring a significant progress in the technological field.


Water ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 2730
Author(s):  
Vladimir Serdyukov ◽  
Nikolay Miskiv ◽  
Anton Surtaev

This paper demonstrates the advantages and prospects of transparent design of the heating surface for the simultaneous study of the hydrodynamic and thermal characteristics of spray cooling. It was shown that the high-speed recording from the reverse side of such heater allows to identify individual droplets before their impact on the forming liquid film, which makes it possible to measure their sizes with high spatial resolution. In addition, such format enables one to estimate the number of droplets falling onto the impact surface and to study the features of the interface evolution during the droplets’ impacts. In particular, the experiments showed various possible scenarios for this interaction, such as the formation of small-scale capillary waves during impacts of small droplets, as well as the appearance of “craters” and splashing crowns in the case of large ones. Moreover, the unsteady temperature field during spray cooling in regimes without boiling was investigated using high-speed infrared thermography. Based on the obtained data, the intensity of heat transfer during spray cooling for various liquid flow rates and heat fluxes was analyzed. It was shown that, for the studied regimes, the heat transfer coefficient weakly depends on the heat flux density and is primarily determined by the flow rate. In addition, the comparison of the processes of spray cooling and nucleate boiling was made, and an analogy was shown in the mechanisms that determine their intensity of heat transfer.


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