Protective Clothing Materials Research Articles

Разработка методики испытаний пакетов материалов одежды специальной защитной пожарных с учетом послойного контроля температуры при нагревании

Цель. Определение защитных свойств пакета материалов при нагреве.
 Методы. Исследование изменения температуры в пакете материалов путем послойного контроля значений при нагреве.
 Результаты. Разработана и представлена установка для проведения экспериментальных исследований изменения температуры в слоях пакета материалов и методика к ней. Проведены экспериментальные исследования, получены числовые характеристики исследуемых пакетов защитной одежды пожарных. Результаты исследований сопоставлены с теоретическим расчетом в среде ANSYS. Погрешность расчетных данных не превышает 7 %.
 Область применения исследований. Результаты исследований могут быть использованы в разработке, исследовании и оптимизации строения и конструкции пакета материалов для защитной одежды пожарных.

Compromise of Personal Protective Clothing from Liquid Exposure.

Following critiques of multiple personal contamination events from entries into the Oak Ridge National Laboratory's Spallation Neutron Source Transfer Bay, it was considered that the most likely causes for contamination were personal protective clothing doffing errors or moisture (sweat) allowing contamination to wick through the protective clothing. Radiological protection staff looked more closely, however, at the specific area of the clothing where contamination was highest; under enhanced lighting and photochromic manipulation, there appeared to have been some type of moisture in the area. Recognizing the possibility that moisture may have allowed for migration of contamination through the clothing, further experiments were undertaken to determine under which conditions this transport might have occurred. The objective for this work was to identify the susceptibility of different types of personal protective clothing to various liquids encountered in the workplace. Several tests were performed to determine if perspiration had enabled migration of contamination and to identify what other liquids might have affected contamination transport. Two layers of personal protective clothing were subjected to static conditions and dynamic conditions to include active rubbing of the materials while wet. Food dye added to each of the liquids tested enabled visual indications of liquid breakthrough. Additional tests were conducted to see if solid contamination could be transported through the materials along with the liquids. All but one type of non-rubberized personal protective clothing in use at Oak Ridge National Laboratory were permanently compromised to some extent by the solvents used for decontamination. It was determined that most common cleaning agents immediately and permanently destroyed the hydrophobic nature of several of the tested protective clothing materials, potentially allowing for radioactive contamination to penetrate through the material to the worker. Work around wet surfaces or performing wet decontamination will only be performed in protective clothing known to prevent transport of the wetting agent.

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

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.

A Multifaceted Evaluation on the Penetration Resistance of Protective Clothing Fabrics against Viral Liquid Drops without Pressure.

Healthcare workers should wear appropriate personal protective clothing (PPC) on assuming the risk of exposure to various pathogens. Therefore, it is important to understand PPC performance against pathogen penetration. Currently, standard methods to evaluate and classify the penetration resistance of PPC fabrics with pressure using synthetic blood or phi-X174 phage have been established by the International Organization for Standardization (ISO). However, the penetration of viral liquid drops (VLDrop) on the PPC without pressure is also a major exposure route and more realistic, necessitating further studies. Here, we evaluated the penetration resistance against VLDrop without pressure using phi-X174 phage on woven and nonwoven fabrics of commercially available PPC classified by the ISO, and analyzed in detail the penetration behaviors of VLDrop by quantifying the phage amounts in leak-through and migration into test fabrics. Our results showed that some nonwoven test fabrics had nearly the same penetration resistance against VLDrop, even if the ISO resistance class differed. Furthermore, the results revealed that the amount of leakage through the fabrics was correlated with the migration amount into the fabric, which was related to fluid-repellency of fabrics, suggesting the effectiveness for penetration resistance. Our study may facilitate more appropriate selection for PPC against pathogen penetration.

Formulation of parameters of three-layer thermal protective clothing based on Fourier’s law

With the rapid development of metallurgy, construction, machinery manufacturing and petrochemical industry, safety accidents often occur under high-temperature working environment. Therefore, this paper analyses the heat conduction process of thermal protective clothing, according to the analysis of unstable heat conduction process with Conservation of Energy and Fourier’s law, so as to get the distribution of temperatures with the thickness variation of the material layer. Furthermore, we shall fit the relation between temperature and the thickness of the material layer when the heat transfer reaches steady state, and then determine the optimal range of the thickness of the thermal protective clothing material layer with the upper bound being the highest temperature which human can tolerate. And it can be promoted to the fields of fire protection, metallurgy, machinery manufacturing and other high temperature work.

Application of A New Firefighter Protective Clothing Material in Fire Rescue

Firefighters are usually exposed to high temperatures, smoke and other hazards from the environment when carrying out fire fighting and rescue. Fire fighting clothes are special protective clothes used to protect firefighters from high temperature and fire damage. PPS fabrics can meet the basic requirements of fire service coatings. According to the standard requirements of a pair of firefighters’ chemical protective clothing, this topic further coats the surface of PPS fabric to achieve a certain chemical penetration resistance, and does basic research on the application of PPS fibers in the outer layer of chemical protective clothing. It can be used to make exterior material of Fire Fighting Protective clothing. Fabric density affects the warp and weft tear properties, but due to the limited fabric density in this design, the density does not affect much. In addition, it has been found that reducing the latitude and longitude density difference can increase the latitudinal tear strength value. The possibility of multi-stage airbag cushioning type pressure-proof protective clothing captured in actual fire-fighting and rescue work is analyzed, which provides a certain guarantee for the safety of fire-fighters during fire-fighting and rescue operations.

Research on Heat Transfer in High Temperature Garments

This paper describes the Law of heat transfer between the layers of material and a method for determining the thickness of layers of material parameters of a high temperature protective clothing. Three important choice of protective clothing material and the air gap layer as the research object, based on the Fourier law and the energy conservation law to establish second order partial differential equation, solving the Crank-Nicolson method by second order partial differential equation, derived temperature, time, the relationship between the thickness. Finally, in the case where the heat transfer ANSYS software simulation under the above conditions, a comparative analysis with calculated transfer law, the error is 1.2%, higher accuracy results.

Effects of heat exposure on the properties and structure of aerogels for protective clothing applications

Abstract In this paper, an attempt has been made to investigate the effects of heat and thermal radiation on the structure and properties of hydrophobic aerogels intended for use in textile materials for protective clothing. A novelty is a comprehensive approach to the subject by considering all aspects relevant to the using of aerogels in clothing protecting against heat and adaptation of test methods commonly used to assess the protective properties of clothing materials for the needs of aerogel testing. The weight changes of aerogels upon heat and radiation exposure was determined by the gravimetric method and thermogravimetric analysis (TGA). The nano- and micro-structure of untreated and heat-treated aerogels was characterized by using scanning electron microscopy (SEM) and atomic force microscopy (AFM). Additionally, Fourier transform infrared spectroscopy (FTIR) and contact angle technique was used to study the chemical structure and hydrophobicity of the aerogels, respectively. Textural characteristics (specific surface area, pore volume, pore size distribution) were determined based on adsorption/desorption isotherms of N2 at 77 K. It was found that the exposure of aerogels to heat led to a reduction in their weight, for example at 180 °C the weight loss was about 2% (irrespective of treatment time), whereas at 350 °C the loss was three times greater and amounted to approx. 7%. The weight loss at 350 °C indicates a slow removal of the surface –CH3 groups, which has been confirmed by the FTIR analysis. The oxidation of methyl groups provides also change the hydrophobic nature of the aerogels demonstrated on the basis of the results of water contact angles. From SEM and AFM images it can be observed that exposure to heat changed the structure and morphology of silica aerogel granules, while aerogel powder was resistant to temperature treatment. The scale of observed changes of the structure and weight of silica aerogels allows their potential use in the design of protective clothing.

Recent Eco-Friendly Developments in Personal Protective Clothing Materials for Reducing Plastic Pollution: A Review

Recent Eco-Friendly Developments in Personal Protective Clothing Materials for Reducing Plastic Pollution: A Review

Recent Eco-Friendly Developments in Personal Protective Clothing Materials for Reducing Plastic Pollution: A Review

Due to the industrialization increase in the 20th century, the level of hazards for public health and the demand for personnel protective clothing (PPC) have increased. The area of PPC has been steered to high tech equipment made from plastic-based materials, which are derived from non-renewable sources and have a long life cycle expanding from hundreds to thousands of years, after their end of useful life. This paper reviews the information related to conventional plastic-based fibers, their properties, advantages, disadvantages, and applications in the battlefield, industry, automobiles, etc. This paper provides a basis for the selection of natural fibers and the replacement of conventional plastic-based fibers to reduce the plastic content in protective clothing or other composites. A comparative analysis of technological, environmental, economic and legal aspects of plastic-based and environment-friendly natural fibers is presented. Natural fiber-based composite protective clothing is found to be environment-friendly and considered to have prospects for the future due to its comparative technological, environmental, economic and legal advantages.

Analysis of the influence of electrospinning process parameters on the morphology of poly(lactic acid) fibres

Purpose: The article focuses on the production of polymer nanofibres from poly(lactic acid) using the electro-spinning method, i.e. the technique of forming fibres in an electrostatic field. The main aim of the publication was to analyse the influence of the distance between electrodes on the morphology of one-dimensional polymeric materials obtained. Design/methodology/approach: In the practical part of the study solutions of polylactide in acetone and a mixture of chloroform/dimethylformamide (DMF) were produced. After 72 hours of mixing, no homogeneous solutions were obtained, therefore a solution consisting of a polylactide dissolved in chloroform was prepared, to which dimethylformamide was added in order to dilute the mixture. The morphology of the nanostructures obtained was analysed by means of a scanning electron microscope (SEM) equipped with an X-ray energy dispersion spectrometer (EDS), which allowed to analyse the chemical composition of the nanofibres produced. The electro-spinning method used to obtain fibres is characterized by high versatility - it gives the possibility to produce fibres from a wide range of polymers. Electro-spinning is also an economic method, and spinned fibres have a wide application potential. Findings: Nanofibres obtained by electro-spinning from the previously produced solution, regardless of the distance between the nozzle and the collector (10 or 20 cm) did not show any significant discrepancies in the values of measured diameters. Fibres obtained at increased distance between electrodes (20 cm) are characterized by a smaller average diameter value, but the difference is small, fluctuating between 48-49 nm. In the case of the sample formed during electro-spinning at the distance of the nozzle - collector equal to 10 cm and the sample produced at the distance doubled, no defects in the structure of the obtained nanofibres were observed. The analysis of topographic images of surfaces produced in the course of nanostructures' work did not show any significant influence of the distance between the nozzle and collector on the diameter of fibres. No defects in the structure of one-dimensional polymer materials obtained allowed to state that the distance between the nozzle and the collector in the range of 10-20 cm is the optimal parameter of the electro-spinning process allowing to obtain smooth, untangled fibres. Practical implications: The fibrous polymer mats obtained during the electro-spinning process of polylactide can be used as protective clothing materials, as drug delivery systems, as tissue scaffolding and as filtration membranes. Originality/value: At present, there are few articles in the literature on the electrospinning process, due to the fact that it is a constantly developing matte for the production of nanofibres. Moreover, most of the research focuses on fibres obtained from nonbiodegradable polymers, which do not have the advantages of fibres obtained from polylactide.

The influence of the marine environment on the properties of clothestextile materials for clothing

The article presents data on the influence of the marine environment on textile materials. Aggressive components of the marine environment that contact the surface of clothing (sea salt and oil) are justified. Sea salt is an integral part of seawater. It accumulates in the clothing structure. Oil is included in the components of seawater in emergency situations at offshore oil and petroleum products and sea transport facilities. This leads to a change in the properties of textile materials, which depend on the concentration of aggressive components in the structure of textile materials. The active concentration of aggressive components in textiles is determined by its ability to absorb liquid. Specific features of changing the volume of various textile fibers during interaction with liquids are established. Structure of sea salt and the chemical composition of oil. This determines the change in the properties of the textile in contact with them. The structure of sea salt and the chemical composition of oil is justified. This determines the change in the properties of textiles. As a result of the systematization of modern data on clothing materials that are used in marine technology, the information base of the leading modern fibrous materials for protective clothing was formed. The reference materials for research are allocated. It was found that the presence of sea salt in a moist contact medium with a surface of a special fabric on a cotton basis for all samples of materials led to a decrease in their capillarity. It has been established that packages of materials based on mixed-fiber fabrics have permeability parameters with respect to crude oil below the cotton garment surfaces. The application in combination with such materials of holofiber insulation reduces the level of saturation of clothing with the liquids examined. The article presents experimental data on the permeability of sea water and oil in special materials for clothing. The work was supported by the Ministry of Education and Science of Russia in the Don State Technical University within the framework of the State task 2017-2019 under the project No. 11.9194.2017/БЧ.

Properties and Applications of Basalt Fiber and Its Composites

Basalt fiber is a green, healthy and environmentally friendly high-tech fiber product without environmental pollution. It is widely used in military and civilian fields. It is not only of great theoretical significance but also of great strategic significance to strengthen the analysis and study of the properties of basalt fiber and its composite materials. The results show that: compared with glass fiber, carbon fiber and aramid fiber, basalt fiber has good mechanical properties, acid-alkali resistance, excellent electrical properties, high wave permeability, non-conductive, and excellent sound insulation and insulation performance. Based on the above advantages, the combination of basalt fiber and substrate can enhance the material properties. Based on the above features, the basalt fiber and its composites can be made into high temperature and low temperature protective clothing and sound insulation materials used in sound absorption and heat insulation industry. Its production can also be widely used in the fields of brake, electric, electromagnetic and so on for its unique features.

New Approaches to Evaluate the Performance of Firefighter Protective Clothing Materials

New Approaches to Evaluate the Performance of Firefighter Protective Clothing Materials

New Approaches to Evaluate the Performance of Firefighter Protective Clothing Materials

This paper presents new proposals in the evaluation and determination of the optimum materials suitable for use in the design and development of firefighter protective clothing by simultaneously addressing the conflicting factors of thermal protection [heat transfer index (HTI), radiant heat transfer index (RHTI) and thermal threshold index (TTI)] and anti-heat stress [water vapor resistance (WVR) and total heat loss (THL)]. To achieve this, this paper proposes new indices for the materials, two types of “total performance” indices, which are defined as the sum and the product of the competing factors of thermal protection and anti-heat stress. The results showed that the candidate materials of firefighter protective clothing were easily rated when the new indices were applied. Of five candidate materials viz. A, B, B1, B2 and C, the B sample, with values for HTI24 = 13.2 ± 0.2 s, RHTI24 = 18.0 ± 0.8 s, TTI = 1132 ± 33 J/m2, WVR = 17.5 ± 0.3 m2 Pa/W and THL = 266.2 ± 4.1 W/m2, was found to exhibit the best total performance. However, the methods proposed to the scientific community in this paper have so far been validated on a limited data set only, and will require further validation by a wider group of researchers and with more samples. Lastly, comments on ISO 11999-3:2015 were also made for the further improvement and development of technical standards.

Comparison of the Filter Efficiency of Medical Nonwoven Fabrics against Three Different Microbe Aerosols.

Exact evaluation of the performance of surgical masks and biohazard protective clothing materials against pathogens is important because it can provide helpful information that healthcare workers can use to select suitable materials to reduce infection risk. Currently, to evaluate the protective performance of nonwoven fabrics used in surgical masks against viral aerosols, a non-standardized test method using phi-X174 phage aerosols is widely performed because actual respiratory viruses pose an infection risk during testing and the phage is a safe virus to humans. This method of using a phage is simply modified from a standard method for evaluation of filter performance against bacterial aerosols using Staphylococcus aureus, which is larger than virus particles. However, it is necessary to perform such evaluations based on the size of the actual pathogen particles. Thus, we developed a new method that can be performed safely using inactivated viral particles and can quantitate the influenza virus in aerosols by antigen-capture ELISA (Shimasaki et al., 2016a) . In this study, we used three different microbial aerosols of phi-X174 phage, influenza virus, and S. aureus and tested the filter efficiency by capturing microbial aerosols for two medical nonwoven fabrics. We compared the filter efficiency against each airborne microbe to analyze the dependency of filter efficiency on the microbial particle size. Our results showed that against the three types of spherical microbe particles, the filter efficiencies against influenza virus particles were the lowest and those against phi-X174 phages were the highest for both types of nonwoven fabrics. The experimental results mostly corresponded with theoretical calculations. We conclude that the filter efficiency test using the phi-X174 phage aerosol may overestimate the protective performance of nonwoven fabrics with filter structure compared to that against real pathogens such as the influenza virus.

Resistance of Type 5 chemical protective clothing against nanometric airborne particles: Behavior of seams and zipper

ABSTRACTIn the field of dermal protection, the use of chemical protective clothing (CPC) (including coveralls) are considered as the last barrier against airborne engineered nanomaterials (ENM). In the majority of cases, Type 5 CPC, used against solid particles (ISO 13982-1), perform well against ENM. But in a recent study, a penetration level (PL) of up to 8.5% of polydisperse sodium chloride airborne nanoparticles has been measured. Moreover, in all the previous studies, tests were performed on a sample of protective clothing material without seams or zippers. Thus, the potential for permeation through a zipper or seams has not yet been determined, even though these areas would be privileged entry points for airborne ENM.This work was designed to evaluate the PL of airborne ENM through coveralls and specifically the PL through the seams on different parts of the CPC and the zipper.Eight current models of CPC (Type 5) were selected. The samples were taken from places with and without seams and with a zipper. In some cases, a cover strip can be added to the zipper to enhance its sealing. Polydisperse nanoparticles were generated by nebulization of a sodium chloride solution. A penetration cell was developed to expose the sample to airborne nanometric particles. The NaCl particle concentration in number was measured with an ultrafine particle counter and the PL was defined as the downstream concentration divided by the upstream concentration.The results obtained show that the PL increased significantly in the presence of seams and could reach up to 90% depending on the seam's design. Moreover, this study classifies the different types of seams by their resistance against airborne ENM. As for the penetration of airborne NaCl particles through the zipper, the PL was greatly attenuated by the presence of a cover strip, but only for certain models of coveralls. Finally, the values of the pressure drop were directly linked to the type of seam. All of these conclusions provide recommendations to both manufacturers and users.

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

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.

Evaluation of a passive method for determining particle penetration through protective clothing materials

ABSTRACTThe risk of workers' exposure to aerosolized particles has increased with the upsurge in the production of engineered nanomaterials. Currently, a whole-body standard test method for measuring particle penetration through protective clothing ensembles is not available. Those available for respirators neglect the most common challenges to ensembles, because they use active vacuum-based filtration, designed to simulate breathing, rather than the positive forces of wind experienced by workers. Thus, a passive method that measures wind-driven particle penetration through ensemble fabric has been developed and evaluated. The apparatus includes a multidomain magnetic passive aerosol sampler housed in a shrouded penetration cell. Performance evaluation was conducted in a recirculation aerosol wind tunnel using paramagnetic Fe3O4 (i.e., iron (II, III) oxide) particles for the challenge aerosol. The particles were collected on a PVC substrate and quantified using a computer-controlled scanning electron microscope. Particle penetration levels were determined by taking the ratio of the particle number collected on the substrate with a fabric (sample) to that without a fabric (control). Results for each fabric obtained by this passive method were compared to previous results from an automated vacuum-based active fractional efficiency tester (TSI 3160), which used sodium chloride particles as the challenge aerosol. Four nonwoven fabrics with a range of thicknesses, porosities, and air permeabilities were evaluated. Smoke tests and flow modeling showed the passive sampler shroud provided smooth (non-turbulent) air flow along the exterior of the sampler, such that disturbance of flow stream lines and distortion of the particle size distribution were reduced. Differences between the active and passive approaches were as high as 5.5-fold for the fabric with the lowest air permeability (0.00067 m/sec-Pa), suggesting the active method overestimated penetration in dense fabrics because the active method draws air at a constant flow rate regardless of the resistance of the test fabric. The passive method indicated greater sensitivity since penetration decreased in response to the increase in permeability.

Effect of Clothing Layers on Mass Transfer of Methyl Salicylate Vapor Through CBRN Materials in a Cylinder Test

Abstract The testing of protective clothing materials against chemical and biological (CB) hazards is usually done at either a swatch of fabric or at the systems level. In this paper, a cylinder test method was developed in combination with a MethylSalicylate (MeS) Simulant test (variant to the MIST test) to study the effect of air-permeable and membrane clothing systems and specifically the effects of layering on protection. Three fabrics, material A air permeable absorptive, material B air impermeable, non-absorptive (membrane) and material C air permeable non-absorptive were tested on the cylinder alone and in combinations at 1 m/s and 10 m/s wind speeds. At high wind speeds, the MeS vapor penetrated all three materials and protection factors (PF) were lower than 10. At the lower wind speed much higher protection was found, PF(material A) = 36, PF(material B) = 29, PF(material C) = 2, and material B showed a significant decrease in protection with a leakage added (PF = 2), which did not occur with material A (PF = 29). When materials A and C were combined the combination of any layer to material A increased protection, especially with material A close to the cylinder: PF = 983 with material A twice, and PF = 765 with material C outside and material A inside. With material C on both layers, essentially no protection was obtained (PF = 2) and with material A outside and material C inside PF was 55, slightly higher than material A alone. In conclusion, the cylinder method provided very useful information in the development of protective clothing systems, especially at the lower wind speed of 1 m/s, and may provide a reliable quick and efficient way to obtain information on protection of air permeable absorptive fabrics. The method provides much more realistic data than current standard swatch tests on such materials and is cheaper and faster than a whole system MIST test.