scholarly journals The Influence of Spherical Nano-SiO2 Content on the Thermal Protection Performance of Thermal Insulation Ablation Resistant Coated Fabrics

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Guoyi Liu ◽  
Yuanjun Liu ◽  
Xiaoming Zhao
Keyword(s):  
Thermal Insulation ◽  
Thermal Protection ◽  
Radiant Heat ◽  
Total Heat Flow ◽  
Residual Mass ◽  
Average Value ◽  
Coated Fabrics ◽  
Average Size ◽  
In Fire ◽  
Protective Performance

In the high temperatures experienced in fire, radiant heat accounts for 80% of the total heat flow; therefore, improving the radiation protection is the best way to enhance the thermal protective performance of thermal insulation ablation resistant coated fabrics. To achieve this goal, the coating process and the ingredients used were optimized, spherical nano-SiO2 and other particles were added, and thermal insulation ablation resistant coated fabrics with high radiant heat reflectivity were prepared. The influence of the spherical nano-SiO2 content on the thermal protection performance of the prepared coated fabrics was investigated. Research showed that (1) the radiant heat reflectivity of the prepared coated fabrics improves significantly with increasing content of spherical nano-SiO2; when the mass fraction of spherical nano-SiO2 is 15%, the reflectivity of coated fabrics is at its largest, and its average value was 74.30%. At present, the average size of grains in samples increased 1.9 times; (2) after adding the spherical nano-SiO2, the thermal stability of the thermal insulation ablation resistant coated fabrics is significantly improved; the residual mass is as high as 88.49% at 1200°C, which is 18.77% higher than the residual mass of the coated fabrics with no spherical nano-SiO2 added at the same temperature.

Effects of the Potassium Titanate Functional Filler Types on the Thermal Protection Performance of Heat Resistant Ablative Coated Fabrics

NANO ◽  
2018 ◽  
Vol 13 (02) ◽  
pp. 1850014 ◽  
Author(s):  
Guoyi Liu ◽  
Yuanjun Liu ◽  
Xiaoming Zhao
Keyword(s):  
Thermal Stability ◽  
Thermal Protection ◽  
High Strength ◽  
Radiant Heat ◽  
Insulation Property ◽  
Minimum Diameter ◽  
Potassium Titanate ◽  
Heat Resistant ◽  
Coated Fabric ◽  
Coated Fabrics

Considering sub-micron potassium titanate whiskers (BX-101), nanoscale potassium titanate whiskers (AX-301), sub-micron potassium titanate whiskers (AX-316) and high strength potassium titanate crystal (AX-319) as functional fillers, heat resistant ablative coated fabrics which have high radiant heat reflectivity were prepared. The effect of the type of functional filler on the thermal protection performance of heat resistant ablative coated fabrics was mainly discussed. Research showed that the microstructure of potassium titanate functional filler had a significant impact on the radiant heat reflectivity and thermal insulation performance of the prepared coated fabric. The coated fabric which took nanoscale potassium titanate whiskers (AX-301) with a minimum diameter and greater length-diameter ratio as functional filler has the highest thermal reflectivity and the best insulation property. Heat ray reflectivity of potassium titanate coated fabrics had positive correlation with their crystallinities. The higher the coated fabric crystallinity was, the greater the heat ray reflectivity. Thermogravimetric analysis results showed that after adding four kinds of potassium titanate fillers, the thermal stability of the prepared coated fabrics was enhanced, and the nanoscale potassium titanate whiskers (AX-301) coated fabrics had the best thermal stability.

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.

Assessment of thermal protective performance of firefighter’s clothing by a sweating manikin in low-level radiation

2019 ◽  
Vol 31 (1) ◽  
pp. 145-154 ◽  
Author(s):  
Zhongxiang Lei ◽  
Xiaoming Qian ◽  
Xianglong Zhang
Keyword(s):  
Thermal Insulation ◽  
Thermal Protection ◽  
New Method ◽  
Thermal Manikin ◽  
Thermal Protective Performance ◽  
Content Type ◽  
Low Level ◽  
Protective Performance ◽  
Changing Rate ◽  
Sweating Thermal Manikin

Purpose The purpose of this paper is to assess the thermal protective performance of firefighter’s clothing by a sweating manikin in low-level radiation. Design/methodology/approach A new method and a novel objective index based on measurements of the sweating thermal manikin are proposed to measure the thermal protection performance of firefighter’s clothing under low-level radiation exposure of 3.0 kW/m2. Finally, the effect of thermal insulation on thermal protective performance of firefighter’s clothing was analyzed. Findings The results reveal that the new index which used the changing rate of core temperature of the clothed manikin is a vital indicator of the thermal protection performance. Furthermore, the results demonstrated that there is a linear correlation between thermal protection performance of firefighter’s clothing and the thermal insulation. Originality/value A new method and a novel objective index are proposed to quantify the thermal protective performance of firefighter’s clothing in low-level radiation.

scholarly journals Influence of Fabric Weave on Thermal Radiation Resistance and Water Vapor Permeability

Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 525
Author(s):  
Ana Kiš ◽  
Snježana Brnada ◽  
Stana Kovačević
Keyword(s):  
High Temperatures ◽  
High Performance ◽  
Thermal Protection ◽  
Water Vapor Permeability ◽  
Radiant Heat ◽  
The Body ◽  
Vapor Permeability ◽  
Weave Structure ◽  
Fabric Structures ◽  
The Impact

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.

Analyzing steam transfer though various flame-retardant fabric assemblies in radiant heat exposure

2016 ◽  
Vol 47 (5) ◽  
pp. 853-869 ◽  
Author(s):  
Yun Su ◽  
Jun Li
Keyword(s):  
Thermal Radiation ◽  
Thermal Energy ◽  
Thermal Protection ◽  
Heat Exposure ◽  
Radiant Heat ◽  
Positive Influence ◽  
Air Permeability ◽  
Fabric System ◽  
Layered Fabric ◽  
Nonfatal Injuries

Protection from steam burns is beneficial to reduce the nonfatal injuries of firefighters in firefighting and rescue operations. A new multifunctional testing apparatus was employed to study heat and steam transfer in protective clothing under low-pressure steam and low-level thermal radiation. Single-, double-, and triple-layered fabric assemblies were selected in this experiment. It is indicated that the existence of hot steam weakens the positive influence of the fabric’s thickness, but increases the importance of the air permeability on the thermal protection. The fabric assemblies entrapping moisture barrier can better resist the penetration of steam through the fabric system, and significantly improve the thermal protection in low steam and thermal radiation exposure due to the low air permeability. Additionally, the total transmitted energy ( Qe) and dry thermal energy ( Qd) under low steam and thermal radiation are dramatically larger than that under thermal radiation ( p < 0.05), while hot steam insignificantly reduces the thermal energy during the cooling ( p = 0.143 > 0.05). The understanding of steam heat transfer helps to provide proper guidance to improve the thermal protection of the firefighter’s clothing and reduce steam burns.

ZIRCONIA FIBERS AS A COMPONENT OF HIGH TEMPERATURE THERMAL INSULATION (review)

2021 ◽  
pp. 79-86
Author(s):  
V.G. Babashov ◽  
◽  
N.M. Varrik ◽  
Keyword(s):  
High Temperature ◽  
Thermal Insulation ◽  
Zirconium Oxide ◽  
Thermal Protection ◽  
Sol Gel ◽  
Precursor Solution ◽  
Technical Literature ◽  
Thermal Protection Systems ◽  
Insulation Materials ◽  
Protection Systems

Based on the analysis of recent publications of scientific and technical literature, data on the production of zirconium oxide fibers used for the manufacture of high-temperature thermal insulation materials are presented. Information is provided on various methods of obtaining zirconium oxide fibers (methods of impregnation of the template and molding of the mixture, sol-gel method of spinning a fiber-forming precursor solution), as well as on the technique of fiber molding (manual pulling, dry and wet spinning, blowing and electrospinning). The use of such fibers for the production of thermal insulation materials (felts, cords and blocks) instead of currently existing materials made of aluminum oxide-based fibers can significantly increase the operating temperatures of the thermal protection systems.

scholarly journals Effect of perspired moisture and material properties on evaporative cooling and thermal protection of the clothed human body exposed to radiant heat

2018 ◽  
Vol 89 (18) ◽  
pp. 3663-3676 ◽  
Author(s):  
Manhao Guan ◽  
Agnes Psikuta ◽  
Martin Camenzind ◽  
Jun Li ◽  
Sumit Mandal ◽  
...  
Keyword(s):  
Human Body ◽  
Material Properties ◽  
Heat Dissipation ◽  
Thermal Protection ◽  
Evaporative Cooling ◽  
Thermal Characteristics ◽  
Radiant Heat ◽  
Physiological Effect ◽  
Heat Gain ◽  
Active Liquid

Perspired moisture plays a crucial role in the thermal physiology and protection of the human body wearing thermal protective clothing. Until now, the role of continuous sweating on heat transfer, when simultaneously considering internal and external heat sources, has not been well-investigated. To bridge this gap, a sweating torso manikin with 12 thermal protective fabric systems and a radiant heat panel were applied to mimic firefighting. The results demonstrated how the effect of radiant heat on heat dissipation interacted with amount of perspired moisture and material properties. A dual effect of perspired moisture was demonstrated. For hydrophilic materials, sweating induced evaporative cooling but also increased radiant heat gain. For hydrophilic station uniforms, the increment of radiant heat gain due to perspired moisture was about 11% of the increase of heat dissipation. On the other hand, perspired moisture can increase evaporative cooling and decrease radiant heat gain for hydrophobic materials. In addition to fabric thermal resistance ( Rct) and evaporative resistance ( Ret), material hydrophilicity and hydrophobicity, emissivity and thickness are important when assessing metabolic heat dissipation and radiant heat gain with profuse sweating under radiant heat. The results provide experimental evidence that Rct and Ret, the general indicators of the clothing thermo-physiological effect, have limitations in characterizing thermal comfort and heat strain during active liquid sweating in radiant heat. This paper offers a more complete insight into clothing thermal characteristics and human thermal behaviors under radiant heat, contributing to the accurate evaluation of thermal stress for occupational and general individuals.

scholarly journals Thermal and Wet Comfort of Fabrics Based on Fractal Dimension of Silicone Coating

2018 ◽  
Vol 13 (1) ◽  
pp. 155892501801300
Author(s):  
Yunlong Shi ◽  
Liang Wang ◽  
Wenhuan Zhang ◽  
Xiaoming Qian
Keyword(s):  
Fractal Dimension ◽  
Thermal Insulation ◽  
Coating Layer ◽  
Fractal Theory ◽  
Barrier Effect ◽  
Evaporative Resistance ◽  
Silicone Coating ◽  
Self Similar ◽  
Warmth Retention ◽  
Coated Fabrics

In this paper, thermal and wet comforts of silicone coated windbreaker shell jacket fabrics were studied. Both thermal insulation and evaporative resistance of fabric increased with an increase in coating area due to the barrier effect of the silicone coating layer. Moreover, the coated fabrics with self-similar structures showed different thermal insulation and evaporative resistance under the same total coating area. Fractal theory was used to explain this phenomenon. Optimal thermal-wet comfort properties were obtained when the fractal dimension (D=1.599) was close to the Golden Mean (1.618). When the fractal dimension of coating was lower than 1.599, fabric warmth retention was not high enough. In contrast, fabric evaporative resistance was beyond the value at which people would feel comfortable when the fractal dimension was greater than 1.599.

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