• Title/Summary/Keyword: Thermal Protective Performance

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Comparison of Thermal Protective Performance Test of Firefighter's Protective Clothing against Convection and radiation heat sources (대류와 복사 열원에 대한 특수방화복의 열보호 성능시험 비교)

  • Kim, Hae-Hyoung;Yoo, Seung-Joon;Park, Pyoung-Kyu;Kim, Young-Soo;Hong, Seung-Tae
    • Fire Science and Engineering
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    • v.31 no.2
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    • pp.17-23
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    • 2017
  • The test methods using convection (flame) and radiation heat sources were compared to evaluate the thermal protective performance of the firefighter's protective clothing. In particular, the influence of the outer shell, mid-layer, and lining constituting the firefighter's protective clothing on the thermal protective performance was compared for convection and radiation heat sources. Tests for the thermal protective performance were carried out according to KS K ISO 9151 (convection), KS K ISO 6942 (radiation), and KS K ISO 17492 (convection and radiation). When tested under the same incident heat flux conditions ($80kW/m^2$), the heat transfer index ($t_{12}$ and $t_{24}$) for the radiation heat source was higher than that for the convection heat source. This means that radiation has a lesser effect than convection. For the convection heat source, the lining had the greatest effect on the thermal protective performance, followed by the mid-layer and the outer shell. On the other hand, for the radiation heat source, the effect on the thermal protective performance was great in the order of lining, outer shell, and mid-layer. Convection and radiation have fundamentally different mechanisms of heat transfer, and different heat sources can lead to different thermal protective performance results depending on the material composition. Therefore, to evaluate the thermal protective performance of the firefighter's protective clothing, it is important to test not only the convection heat source, but also the radiation heat source.

Effect of Fire Fighters' Turnout Gear Materials Air Gap on Thermal Protective Performance (소방보호복 소재의 공기간극이 열보호 성능에 미치는 영향)

  • Lee, Jun-Kyoung;Kwon, Jung-Suk
    • Fire Science and Engineering
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    • v.28 no.4
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    • pp.97-103
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    • 2014
  • To ensure adequate protection from the risk of burns, fire fighter's turnout has a composite of more than three components and air gaps between layers of materials. During the flame exposure, radiation and convection heat transfer occurs in the air gap, thus the air gap acts as a thermal resistance with non-linear characteristics. Therefore, in this study, the experiments were performed to identify the effect of various air gap width (0~7 mm) on the thermal protective performance of fire fighter's clothing. The temperatures on each layer and RPP (Radiant Protective Performance, the most effective index representing the thermal protective performance) were measured with various incident radiant heat fluxes. The temperature at the rear surface of the garment decreased and RPP increased with increasing air gap width because the thermal resistance increased. Especially, it could be found that RPP value and air gap width has almost linear relation for the constant incident heat flux conditions. Thus relatively simple RPP predictive equation was suggested for various incident heat flux and air gap conditions.

Development of Firefighters' Personal Protective Clothing with Nomex Honeycomb Fabric and its Protective and Comfort Evaluation (노멕스 허니콤 구조 직물을 적용한 소방관용 특수방화복 개발 및 이의 보호 쾌적 성능평가)

  • Jung, Jae-Yeon;Ku, Ponjun;Kim, Do Hyung;Kwon, Min-Jae;Kang, Sungwook;Choi, Jeong-Yoon;Lee, Joo-Young
    • Fashion & Textile Research Journal
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    • v.21 no.5
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    • pp.606-617
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    • 2019
  • The present study newly developed a firefighters' protective jacket and pants using a Nomex honeycomb structured layer (HPC) in cases of being exposed to flashover or flameover. This study evaluated the protective and comfort functions of an HPC compared to the current KFI firefighters' protective clothing (FPC). The results are as follows. First, thermal protective performance (TPP) of fabric layers was 2.75 times greater for HPC than FPC at $125kW/m^2$. Second, the predicted second and third degree burn areas were smaller for HPC than FPC when using a flame manikin. Third, thermal insulation using a thermal manikin was 0.2 clo greater for HPC than FPC. Fourth, there were no marked differences in maximal performance, mobility, and microclimate temperature/humidity between FPC and HPC through human wear trials. The thermal insulation of HPC was higher than that of FPC; however, any negative effect of HPC thermal insulation on the comfort functions for firefighters was not found. In conclusion, the newly-developed HPC provided more protection in reducing burn injuries from $125kW/m^2$, while no negative impact on maximal performance, mobility and thermal comfort functions of firefighters, which is appropriate for quick-evasive tactics at the flashover, flameover or back draft fires.

Thermal Insulation of Protective Clothing Materials in Extreme Cold Conditions

  • Mohamed Zemzem;Stephane Halle;Ludwig Vinches
    • Safety and Health at Work
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    • v.14 no.1
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    • pp.107-117
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    • 2023
  • Background: Thermophysiological comfort in a cold environment is mainly ensured by clothing. However, the thermal performance and protective abilities of textile fabrics may be sensitive to extreme environmental conditions. This article evaluated the thermal insulation properties of three technical textile assemblies and determined the influence of environmental parameters (temperature, humidity, and wind speed) on their insulation capacity. Methods: Thermal insulation capacity and air permeability of the assemblies were determined experimentally. A sweating-guarded hotplate apparatus, commonly called the "skin model," based on International Organization for Standardization (ISO) 11092 standard and simulating the heat transfer from the body surface to the environment through clothing material, was adopted for the thermal resistance measurements. Results: It was found that the assemblies lost about 85% of their thermal insulation with increasing wind speed from 0 to 16 km/h. Under certain conditions, values approaching 1 clo have been measured. On the other hand, the results showed that temperature variation in the range (-40℃, 30℃), as well as humidity ratio changes (5 g/kg, 20 g/kg), had a limited influence on the thermal insulation of the studied assemblies. Conclusion: The present study showed that the most important variable impacting the thermal performance and protective abilities of textile fabrics is the wind speed, a parameter not taken into account by ISO 11092.

Research on Winter Working Environment and Working Clothes at a Construction Site (겨울철 건설현장의 작업 및 의복 환경 실태 조사)

  • Jeong, Jeong-Rim;Kim, Hee-Eun;Rissanen, Sirkka
    • Fashion & Textile Research Journal
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    • v.11 no.1
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    • pp.174-179
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    • 2009
  • The purpose of this study is to research the actual condition of working environment, working clothes and personal protective equipments on workers at a construction site in winter. The one to one interview by questionnaire was performed with 33 males and 2 females workers of a construction site in Daegu at $1.3^{\circ}C$ air temperature, 28% R.H., 4.7m/sec air velocity. The questionnaire consisted of 21 questions including 4 personal characteristics questions, 12 working environment/performance questions and 5 working clothes/personal protective equipments questions. It was modified from the original questionnaire developed by Finnish Institute Occupational Health. We found that physical stress of workers increased and the ability of performance decreased. The workers felt the coldest at hands/fingers, feet/toes and the face part of cheek, nose and ears. They rarely wore thermal clothing for winter and answered that the thermal gloves for winter did not provided enough warmth. Even if the workers recognized the necessity of personal protective equipments for their safety, they did not wear them for efficiency of working performance. These results will be useful elementary materials for development of working clothes and personal protective equipments from the viewpoint of improving both working performance and comfort.

Assessment of Thermal Protection Performance of Firefighting Garments for Hydrogen Jet Fire (수소제트화재에 대한 특수 방화복의 열 방호 성능시험 평가)

  • UNGGI YOON;BYOUNGJIK PARK;YANGKYUN KIM;SUNGWOOK KANG;OHKKUN LIM
    • Transactions of the Korean hydrogen and new energy society
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    • v.35 no.3
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    • pp.310-317
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    • 2024
  • In this study, Aimed to develop technology to ensure the safety of firefighters responding to hydrogen incidents and to review the performance of protective super absorbent polymer (SAP) that could help maintain the thermal protection performance of equipment with protective properties. Tests were conducted, including bench-scale and full-scale thermal exposure tests, to review the protective performance of SAP using firefighting garments commonly used by firefighters. The results showed that without SAP application, 2nd degree burn areas were measured at 9.4%, and 3rd degree burn areas at 7.7%. In contrast, when SAP was applied, the percentage of 2nd degree burn areas decreased to 7% on the lower body, and there was no temperature rise causing 3rd degree burns. Therefore, it is expected that by applying SAP to the outer surface of firefighter garments, even under temporarily high temperature conditions such as hydrogen jet flames, thermal damage to firefighters could be protected for a certain period.

Dispersant Effect on Thermal Performance of SG (증기발생기 열성능에 미치는 분산제 첨가효과)

  • Lee, Jae-Keun;Moon, Jeon-Soo;Yoon, Seok-Won;Maeng, Wan-Young
    • Transactions of the Korean hydrogen and new energy society
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    • v.22 no.4
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    • pp.546-551
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    • 2011
  • The corrosion on steam generator tubes of the secondary side of pressurized water reactor inhibits heat transfer. One of the most efficient techniques improving the heat transfer performance of a nuclear electric generation is a corrosion control. The environmental parameters mostly affecting corrosion are materials and chemical additives. It seems that no further corrosion occurs in steels with Polyacrylic acid polymer dispersant treatment. Polyacrylic acid forms a protective coating with uniform thickness on metal surface. Polyacrylic treatment appears to be the most convenient way to enhance the thermal performance by the thermal conductivity improvement in steam generators.

Study on the Weight Reduction of Firefighter's Protective Clothing by Using Air Layer and Aerogels (공기층과 에어로젤을 이용한 특수방화복 경량화 연구)

  • Kim, Hae-Hyoung;Park, Pyoung-Kyu;Kim, Young-Soo;Hong, Seung-Tae
    • Fire Science and Engineering
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    • v.32 no.1
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    • pp.81-88
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    • 2018
  • Air and ultra lightweight aerogels were used to lighten the weight of the firefighters' protective clothing. In order to lighten the firefighters' protective clothing composed of 3 layers (outer shell, mid-layer, lining), it was most effective to replace the lining which occupied the largest weight in the total weight with the new materials. Thermal protective performance tests were carried out on flame (ASTM D 4108), radiant heat (KS K ISO 6942) and mixing heat (KS K ISO 17492) of flame and radiation. When the lining felt was replaced with an air layer, the air layer must be at least 3 mm to meet the KFI and ISO standards for the thermal protective performance. However, even if the thickness of the air layer increased to 10 mm, the thermal protective performance was lower than that of the existing products. When the felt was replaced with aerogels, the TPP rating (ASTM D 4108) satisfied the KFI standard at the 2 mm thickness of the aerogels. When the thickness of the aerogels was 3 mm, the TPP rating was improved about 140% compared to the existing products. It was confirmed that not only weight reduction but also thermal protective performance was improved by use of aerogels. However, due to the fragile nature of aerogels, a method of fixing them to a constant thickness between layers constituting a firefighters' protective clothing should be considered in the future.

Thermal Comfort Aspects of Pesticide-protective Clothing Made with Nonwoven Fabrics

  • Choi Jong-Myoung;Tanabe Shin-Ichi
    • International Journal of Human Ecology
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    • v.3 no.1
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    • pp.55-72
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    • 2002
  • The purpose of this study was to evaluate the thermal resistance of pesticideprotective clothing and to investigate its subjective wear performance. Three different nonwoven fabrics, which provide barrier properties against water and pesticide, were used to manufacture the experimental clothing: spunbonded nonwoven (SB), spunbonded/meltblown/spunbonded nonwoven (SM), and spunlaced nonwoven (SL). The thermal insulation values of the experimental clothing were measured with a thermal manikin, and other wear trials were performed on human subjects in a climate chamber at $28^{\circ}C$, with 70% R.H. and air movement at less than 0.15m/s. Our results found that the thermal resistance was lower in the SB experimental clothing than in the others; that the mean skin temperature of subjects who wore the experimental clothing made with SL was significantly lower than that of subjects who wore the SB and SM clothing; and that the microclimate temperature and humidity with SB were significantly higher than that of the others. Overall, the experimental clothing made with SL was more comfortable than the others in terms of subjective wear sensations.

Study on the Thermal Protective Performance Measurements of Fire Fighter's Protective Clothing for Low Level Radiant Heat Exposures (저열유속 조건의 복사열 노출에 따른 소방보호복의 열보호성능 측정에 관한 연구)

  • Lee, Jun-Kyoung;Bang, Young-Jun;Bang, Chang-Hoon;Kwon, Jung-Suk
    • Fire Science and Engineering
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    • v.28 no.2
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    • pp.1-8
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    • 2014
  • Despite advancements in the development of synthetic fibers and materials that provide better insulation, fire burn injuries remain a significant issue. To ensure adequate protection, clothing and equipment must be selected on the basis of performance. There are different standards like ISO standards applicable to each of the various types of clothing used by fire fighters. But, in most cases, the tests are performed in the conditions of high heat flux exposure, the clothing material can be destroyed easily. Thus the effective way to investigate the protective performance for the low (radiant) heat flux conditions should be needed. Therefore improved RPP (Radiant Protective Performance) test method based on the onset of pain burn injury was suggested. Experiments were performed to verify the proposed method with current protective clothing for fire fighters and the transient heat transfer characteristics were identified, also. Moreover, several protective performance indices were acquired from experimental results to analyze their relations.