Performance Of Protective Clothing Research Articles

Protective and Comfort Performance of Fire Protective Clothing

The study examined the fire protection performance of several woven products. Given that the comfort and fire protection properties of fire protective clothing (FPC) are opposite, it is important to consider the specific needs of firefighters when selecting the most suitable structure from various plain-woven derivatives, such as plain, basket, and ripstop. The yarn used was Nomex IIIA, which is a type of meta-aramid fibre. To achieve different thread densities, the pick density was adjusted while keeping the end density constant. The physical characteristics, thermal protective performance, thermal resistance, thermal conductivity, water vapour transmission rate and air permeability of all samples were assessed according to the appropriate standards. The goal was to identify the weave structure with the highest performance and the most optimal thread density. The basket weave structure was proposed as a fire protective clothing (FPC) having comfort qualities at a moderate level. Furthermore, increased density provided enhanced fire resistance, however, comfort must be sacrificed. Thus, to achieve a balance between fire protection and comfort, it was recommended to choose a thread density that is of an average level and the suggestion made by this research is to use the fabric as a basket weave design with an ends per inch of approximately 42, it is recommended to retain the pick density within the range of 46 with 44 tex Nomex IIIA yarn. The results of this study may be replicated in other designs using Nomex IIIA and comparable types of cloth and weave specifications.

Experimental study on the cooling performance of medical protective clothing coupled with phase-change cold storage materials

To solve the problems of poor cooling and moisture permeability of the normal medical protective clothing. A scheme of coupling the phase change cold storage material 1-dodecanol to normal medical protective clothing was proposed. Then the effect of phase change cold storage material on the cooling performance of the normal medical protective clothing internal microenvironment was studied under different conditions. The results showed that compared with normal medical protective clothing, when frontline medical workers wore the phase change medical protective clothing for light labor at 24℃ of the chamber temperature within 1 h, the temperature fluctuation can be effectively reduced by 30 %. One piece of phase change materials package was set up in the head, arm and leg, respectively. And four Phase change materials packages were set up in the chest and back, respectively. The test results showed that the internal temperature of the Phase change medical protective clothing could be sustained reduction of 8 %. The internal relative humidity increased by about 21 % compared with the normal medical protective clothing. The thermal comfort of the MPC was improved by 62.55 %, 26.43 % and 6.37 % for the head, back and chest, respectively. The remaining parts should be considered for future work.

A modified model to assess the thermal protective performance of fire-retardant clothing exposed to both flame and radiant source

The present work evaluates the thermal protective performance (TPP) of a multi-layered fire-resistant fabric system subjected to a high intensity risky thermal environment integrating both flame and radiant heat exposure by developing a modified model for the fabric as well as the skin. The present numerical analysis takes into consideration a multiple-layer flameproof gear (outer shell, moisture barrier, and thermal liner), an airgap separating fabric and skin, and a three-layer of skin (epidermis, dermis, and fat layer). The present model is formulated by considering a two-flux model for the radiative heat interaction in the porous fabric medium and a nonlinear bioheat transfer model for the multi-layered skin. The radiative part of the total incident energy from the flame and the radiant heater is considered to be absorbed, emitted, reflected, and transmitted through the porous fibrous layer. Here, a two-flux model is implemented to simulate the self-emission of hot gas trapped inside the porous fabrics. The thermal response in multi-layered skin is analysed using a non-linear bioheat transfer model considering a temperature dependent thermal conductivity of the living tissue. Purely radiant exposure markedly impairs turnout gear protection, while performance deteriorates more gradually with increased convective thermal energy. Greater fabric transmissivity negatively affects skin temperature distribution and TPP ratings more than equivalent reflection reduction. These study results aid in enhancing flame-resistant fabric thermal protection.

Effects of air gap and compression on the dual performance of multilayer thermal protective clothing under low radiant heat

An air gap in thermal protective clothing (TPC) plays an important role in determining heat transfer, but it may also increase the amount of stored thermal energy that would discharge to the skin after exposure, especially when the TPC suffers compression. To investigate the effect of air gap and compression on the dual thermal protective performance (TPP), thermal hazardous performance (THP) and overall thermal protective performance (OTPP) of TPC, nine air gap configurations with different sizes and positions and five compression levels were designed in this study. Regression models were established to explore the relationships among air gap size, compression and THP for different air gap positions. The results demonstrate that increasing the air gap size without exceeding 12 mm not only significantly enhances the TPP by impeding heat transfer from the heat source to the fabric system during exposure but also decreases the THP by reducing heat discharge from the fabric system to the sensor even when compression is applied. Although an inner air gap contributes more to increasing the TPP during exposure than an outer air gap, it may also bring about severe stored energy discharge when compression is applied. It suggests that a larger air gap size should be divided into individually separate air gaps within different fabric layers to reduce the heat transfer during exposure as well as lower the stored thermal energy discharge after exposure.

Thermal performance of protective clothing (firefighter) under extreme ambient conditions

Protective clothing is made up of multiple layers of textile, which include thermal barrier, moisture barrier, chemical protection and heat radiation protection layers etc. This clothing is commonly used by workers working in the chemical industry, blast furnaces, glass industry, industrial boilers and many more. The ambient conditions for these workplaces are humid and hot in which the clothing is designed for the external protection of heat and fluids but the neglected issue is the internal heat and moisture accumulation. This makes the clothing extremely uncomfortable and significantly reduces the workability of the wearer. The multi-layered structure of this clothing causes the body moisture and heat to trap in between layers, which in extreme ambient conditions like working near the furnace or flash fire causes body burns, these “steam burns” are common and considered to be caused by the condensed moisture trapped in the layers of protective garment. This research aims to firstly investigate the moisture flow through hybrid textile layers and its effect on heat transfer and then secondly to see the impact of extreme radiation flux on the moisture flow inside the textile layers and improvement by using Aerogels.

Enhancing heat protection performance of firefighters’ protective clothing: A comparative analysis of fabric and knit structure in the lining of multi-layered construction

A firefighting protective clothing item is an important piece of equipment that can protect firefighters from the risk of burns during firefighting and rescue activities. In this study, a method to improve the heat protection performance of firefighter protective clothing lining was proposed, while consulting with textile experts. The protective performance effects of flame and radiant heat were investigated according to the quilting spacing (25.4, 50.8, and 76.2 mm) of the lining and weaving method (fabric or knitted) used for the multi-layered structure of the protective clothing. The experiments conducted to evaluate the impact of different weaving methods on the protective performance of firefighter clothing against flame, radiant heat, and combined flame/radiant heat revealed that the knitted lining exhibited excellent protection performance. Specifically, the knitted lining demonstrated a delayed effect in temperature increase, with maximum delays ranging from approximately 2.2–4.0 s for flame protection experiments, and 5.7–7.4 s for radiant heat protection experiments. For knitted lining, one thread is woven in an interlocking manner; thus, the heat resistance is higher and thermal conductivity is lower owing to the formation of a space compared that for a fabric lining. The results suggest that the weaving method affects the heat transfer according to the formation of space and change in the thickness of the clothing. The findings of this study could be useful for many purposes, such as cost effective and quick analysis of the expected performance of a design or weaving method.

Personal protective equipment for welders - conformity assessment, classification and performance of protective clothing

U radu je dan prikaz podjele zaštitne opreme za zavarivače, materijala od kojih se izrađuje te usklađenih hrvatskih norma u području primjene europske Uredbe (EU) 2016/425 o osobnoj zaštitnoj opremi. Prema odredbama predmetne Uredbe opisan je postupak ocjene sukladnosti i certificiranja osobne zaštitne opreme za zavarivače s obzirom na II. kategoriju rizika od kojih treba pružiti zaštitu. S posebnim osvrtom na zaštitnu odjeću za zavarivače dan je detaljni pregled zahtjeva koji se postavljaju na gotove odjevne proizvode i sastavne materijale od kojih se izrađuju – kožu i tekstilne materijale. Definirane su ispitne metode za provjeru specifičnih značajki i ocjenu sukladnosti zaštitne odjeće za zavarivače te odgovarajuća razredba razine zaštite, utvrđenih normom HRN EN ISO 11611:2015, a usklađenih s bitnim zdravstvenim i sigurnosnim zahtjevima Uredbe (EU) 2016/425.

The behaviour of quasi-static puncture resistance property for textile body armor soft panels

Purpose This paper aims to estimate the performance of protective clothing used to resist puncture (anti-stab property). Design/methodology/approach Seven single-layer (one layer) samples were investigated in this research. The first three samples were already used for the purpose of (anti-stab property), manufactured from Du-Pont product (commercial samples). The rest of the samples were locally designed and manufactured for the same purpose. These seven samples have then been examined after been added in conjunction with WL Kevlar XP (S 104) witness multilayers (eight layers) panel to create which are called multilayer samples. Findings The results of the statistical analysis for one-way ANOVA illustrated significant effect for single layer samples for all properties. While for multi-layer samples, the results showed a significant difference for all variables except displacement. The Tukey post hoc test observed a significant effect for some samples; also, other samples show a non-significant effect between samples. Originality/value It was observed that the locally manufactured samples serve the purpose as (anti-stab samples) compared with the commercial samples. The radar chart shows that for single-layer sample, the fifth sample fulfill the highest radar chart area, whereas for multi-layer samples, the sixth sample achieved the highest radar chart area.

Studies on the effect of process parameters on the thermal protective performance of multilayer thermal protective clothing

Structural parameters of multilayer thermal protective clothing have a significant influence on thermal protective performance. Variation of pick density in the shell layer, number of layers in the thermal liner, and heat flux is used to study the protection time of thermal protective clothing under high-intensity radiant heat flux. A multi-parametric experimental equation is derived using the Box-Behnken model for accurate predictions and analysis. The test is performed according to ASTM F 1939. The analysis of 3D contours provides us with detailed information on the performance of thermal protective clothing at 1, 2, and 3 layers for various combinations of pick density and heat Flux. The model has a F-value of 309 and a p-value of .0001, indicating that it is statistically significant. The coefficient of correlation between predicted and observed values of protection time is 0.99, which indicates a strong correlation.

Assessment of Thermal Performance of Phase-Change Material-Based Multilayer Protective Clothing Exposed to Contact and Radiant Heat

The research presented in this article concerns the thermal properties of multilayer protective clothing, specifically, the impact of phase-change material (PCM) incorporation on the occurring heat transfer. Multilayer textile assemblies with PCM inserts (macrocapsules containing n-octadecane) and reference assemblies with PP inserts (macrogranules from polypropylene) with very similar geometry and the same textile layers were tested. The spatial geometry of tested assemblies was examined using high-resolution X-ray microtomography (micro-CT). The heating process of the assemblies was examined under the conditions of exposure to contact heat (using thermography) and radiant heat (using a copper plate calorimeter, according to EN ISO 6942). PCM-containing assemblies achieved a temperature rise of 12 °C in a longer period than the reference assemblies; for the contact heat method, the time was longer by 11 and 14 min, and for the radiant heat method by 1.7 and 2.1 min.

Influences of moisture management performance and continuous sweat rate on heat transfer through firefighting clothing under radiant exposure

Human continuous sweating can adjust the thermal protective performance (TPP) of clothing for firefighters by controlling moisture distribution and transfer, which can provide extra thermal protection or injury. To accurately evaluate the heat transfer performance, a calibrated sweat simulant sensor was applied to investigate the influence of moisture management performance (MMP) of materials on the TPP under continuous sweating at a low-level thermal radiative intensity of 8.5 kW/m2. The results revealed that the dual role of continuous sweating on the TPP depended on sweat rate, fabric layers, material properties of the inner layer, and exposure time. The MMP could reduce the heat transfer performance at a high sweat rate for prolonged work, leading to a maximum decrease of absorbed thermal energy up to 16.93% and 49.03% for single and multi-layer fabrics, respectively. The second-degree skin burn occurred in half of the exposure process, and the skin burn time was reduced by up to 5.57% for multi-layer fabrics with good MMP due to the limited increase in thermal conductivity during initial exposure. This study provides a more comprehensive understanding of accurately assessing thermal damage and offers some guidance for selecting the inner layer materials of firefighting protective clothing for various firefighting conditions.

Local effects of printed logos and reflective striping fixed to firefighter clothing material packages under low radiation exposure.

Notifications that related 1st degree burns to reflective striping and impermeable clothing elements did reach the investigators, while the mechanisms behind this phenomenon are still unclear. Material tests for thermal and evaporative resistance, and for heat transmission under dry and wet conditions at low radiation levels were done to evaluate the performance of protective clothing with and without printed logos or reflective striping. The results under the specified conditions showed reduction of heat loss capacity under impermeable elements from dry to wet conditions. Reflective surfaces, even when more impermeable, showed still lower heat transmission through the textile package than materials without striping under tested moisture and radiation combinations. It can be expected that the reported 1st degree burns were related to clothing design and tightness/fit rather than to reflective striping. However, due to the fine balance between clothing thermal and evaporative resistance, outer material emissivity, moisture quantity and location in clothing and applied radiation level, a different setup could lead to different results.

Preparation and Properties Evaluation of Photocatalytic Self-Cleaning Aramid Fabric Based on SiO2-TiO2-Fe Composite Aerogels

Because of the fire scene belonging to the coexistence of mud, ash, oil, and other stains, fire clothing is easy to stain, and frequent washing also reduces the protective performance of clothing and even shortens service life. To improve the self-cleaning properties of aramid fabric, N,N-dimethyl hexamide (DMAC), butyl titanate, tetraethoxysilane, butyl ferrate, polydimethylsiloxane, and N-hexane were prepared and mixed on the surface of the fabric. And the surface morphology, self-cleaning, and flame retardancy of fabric before and after treatment were systematically investigated. The results showed that compared with the untreated fabric, the surface of the treated fabric had a rough microstructure; PDMS/SIO2-TIO2-Fe composite was uniformly coated on the surface of the aramid fabric by the one-step spraying method. The flame retardancy decreased slightly but remained within the standard requirement of the B1 grade. The self-cleaning and anti-fouling properties of the finished aramid fabric were improved obviously. The results provided a theoretical basis for the preparation of high-performance fire-fighting fabrics with the advantages of water-saving, energy-saving, reducing the amount of chemical detergent and being friendly to the environment. The utility model reduced the economic loss and the waste of resources because of the decrease in the function of the fire-fighting clothing caused by the washing and the elimination to a certain extent.

Performance analysis of shell fabric of fire protective clothing for different process parameters

Horizontal and vertical orientations of fabric were used to enhance the performance of fire protective clothing. Using response surface methodology, a multi-parametric experimental equation is obtained for calculating HT and VT for horizontal and vertical orientations, respectively, and creating the relationship between process parameters such as moisture content (M: 0% to 100%), heat flux (Q: 21 to 63 kW/m2), and microclimate thickness (d: 0 to 25 mm). The good correlation coefficient (R 2 = 0.973 and 0.967 for horizontal and vertical orientation, respectively) between the two sets of estimates is observed. The improvement in protection time due to heat flux (Q), microclimate thickness (d), and moisture content (M) for both horizontal and vertical orientation is 55%–56% at M = 100% and d = 25 mm, 22%–23% at Q = 63 kW/m2 and M = 100%, and 36%–39% at Q = 63 kW/m2 and d = 25 mm, respectively.

Investigation of the dual performance of thermal protective clothing with deformation under low radiant heat exposure

Occupational workers in thermal exposure have frequent physical activities that may lead to fabric deformation of thermal protective clothing. To deeply understand the impact of fabric deformation on its dual thermal protective and thermal hazardous performance, a modified experimental instrument was used to simulate different extents of fabric tensile deformation and compression deformation. The results demonstrated that increasing tensile ratios during exposure decreased heat storage within a fabric system, but increased the skin absorbed energy. Tensile ratios had a more negative impact on the thermal protective performance of a single-layer fabric than of a double-layer fabric system. Increasing tensile ratios during cooling decreased heat discharge to the skin, but the applied compression significantly improved the heat discharge. In addition, regression models were established to examine the effect of fabric deformation and demonstrated that the thermal hazardous performance of fabrics was more affected by compression than by tensile deformation.

Durability of metallic coating for improvement of thermal protective performance of firefighter protective clothing

The objective of this study is to investigate the durability of metallic coating for firefighter protective clothing when subjected to different washing cycles. Firefighter clothing ensemble consists of three layers, i.e. outer shell, moisture barrier, and thermal liner. The exposed surface of the outer shell was coated with silver particles through the physical vapor deposition process also called Magnetron sputtering. Afterwards, these specimens were exposed to radiant heat transmission machine at 30 kW/m2 and 40 kW/m2, respectively. It was found that specimens coated with silver particles showed improved thermal protective performance as compared to uncoated specimens. Later on, silver-coated specimens undergo five cycles of washing and their thermal protective performance in terms of transmitted heat flux density Qc (kW/m2) and radiant heat transmission index (RHTI 24 and RHTI 12) was measured. It was found that after five washing cycles, there was a negligible decline in thermal protective performance when exposed to 40 kW/m2. Afterwards, bending moment and water vapor resistance properties were measured before and after five washing cycles. It was inferred that there was no considerable difference in bending moment and water vapor resistance after different washing cycles, which confirmed stability of silver coating layers. However, when silver-coated outer shells were evaluated for abrasion resistance, there was a substantial decline in thermal protective performance on exposure to 40 kW/m2 after one hundred to five hundred cycles of abrasion.

Designing a Mathematical Model to Determine the Heat Protective Performance of Special Clothing for High-Temperature Operation

This paper designs a mathematical model to determine the heat protective performance of special clothing for high-temperature operation. This is an important protective measure for high-temperature operation. Based on the known material parameters of special clothing, experimental data are obtained by simulating the actual situation and fitted with MATLAB software. A mathematical model to determine the heat protective performance of special clothing for high-temperature operation is established, which solves the issue of determining the optimal thickness of special clothing for high-temperature operation in certain conditions.

Impact of ultraviolet radiation on thermal protective performance and comfort properties of firefighter protective clothing

In this study, the impact of ultraviolet radiation is studied on thermal protective performance and clothing comfort properties of firefighter protective clothing. Firefighter clothing assembly consists of the outer shell, moisture barrier and thermal barrier. In this research, two different outer shells were utilized. Outer shell O1 consists of inherently fire- retardant fibres mainly consisting of Conex (Nomex) and firefighter assembly having Conex as the outer shell was called specimen A. On the other hand, clothing arrangement which employed Proban coated outer layer (O2) was termed as specimen B. Both specimens were evaluated for tensile testing, air permeability, radiant heat transmission machine, bending moment and water vapour resistance before and after exposure to ultraviolet radiation. The tensile strength value of outer shell O2 was higher than that of O1 before and after exposure to UV radiation. Tensile strength values of both outer shells O1 and O2 decline after exposure to ultraviolet radiation. Air permeability values of both outer shell O1 and O2 increase after being exposed to ultraviolet radiation. It was noted that specimen A has better thermal protective performance as compared to specimen B, before and after exposure to UV radiation. Also, radiant heat transmission index RHTI 24 values were greater for specimen A as compared to specimen B, before and after exposure to UV radiation. Moreover, bending moment values for both outer shell O1 and O2 decline after being subjected to UV radiation. Furthermore, Water vapour resistance values of outer shell O1 and outer shell O2 enhance after exposure to ultraviolet radiation.

The impact of water on firefighter protective clothing thermal performance and steam burn occurrence in firefighters

Exposure to oscillating heat fluxes while having variable water contents in the thermal protective clothing (T.P.C) is possible in a real firefighting scenario. The occurrence of steam burns becomes inevitable in certain conditions which are still unidentified in the literature. In light of such, in this study, the effect of water distribution on thermal protective clothing (T.P.C) performance is studied for various environmental conditions (i.e., fixed and transient values of heat flux). A numerical approach is used to simulate heat and mass transport in the T.P.C.. Parametric studies are performed, where the exposure heat flux (0–80 kW/m2) and initial quantities of water in the T.P.C. are varied and correlated with second–degree burn times. The presence of water in the outer shell increases second-degree burn times, while water in the inner layer has the opposite effect for high heat fluxes. For the tested heat fluxes, burns obtained are majorly of a scald nature. The results generated allow for identifying environmental and protective clothing conditions where steam burns may become a potential hazard. This study can directly impact the proceedings for firefighters to take in certain environmental conditions and aid in the design of more effective firefighting protective suits.

Numerical investigation of the effects of heterogeneous air gaps during high heat exposure for application in firefighter clothing

For accurate prediction of thermal protective performance of firefighter clothing, a realistic assumption about the heterogeneous distribution of air gaps underneath the clothing is necessary. In this study, a numerical model of heat transfer through realistic heterogeneous air gaps under flash fire exposure was developed. First, the models of heat transfer and fluid motion were validated with data from scientific literature. The verified model was further developed and then used in a subsequent parametric study to quantify effects of heterogeneous air gap distributions. The results revealed that the difference in terms of heat transfer and skin burn injuries between heterogeneous air gaps with contact folds and equivalent homogeneous air gaps was greater than that between heterogeneous air gaps with non-contact folds and equivalent homogeneous air gaps. Fold aspect ratios showed a more prominent impact on heat transfer and skin burn times in the case of contact folds compared to non-contact folds. Exposure times to skin burn were continuously prolonged with increasing air gap thickness from 6.4 to 19.1 mm for homogeneous air gaps and heterogeneous air gaps with non-contact folds, while for heterogeneous air gaps with contact folds, there was an optimum air gap thickness around 12.7–15.9 mm.