Design Of Protective Clothing Research Articles

Relationship between firefighter protective clothing design ease and heat stress

PurposeClothing fit, including garment ease and drape, impacts the volume of air between clothing layers and the body, directly affecting the amount of heat that can be transferred through a multi-layer clothing system. As most acute firefighting fatalities are caused by overexertion and heat strain, the purpose of this research was to determine the impact of ease allowances on air gaps in structural firefighting turnout suits and their subsequent effect on total heat loss (THL) when worn on a three-dimensional form.Design/methodology/approachFour turnout suits with chest ease allowances of 6″, 8″, 10″ and 12″ were evaluated using an ANDI dynamic sweating thermal manikin. The average predicted manikin THL of each ensemble was calculated from the thermal and evaporative resistance measurements. A three-dimensional (3D) body scanner was utilized to calculate the distance and volume of clothing air gaps between the base layer and each turnout suit.FindingsResults demonstrate that reductions in upper body ease measurements trend towards statistically significant increases in THL, to a point, with fit limitations being reached before benefits can be significantly realized. An increase in standard chest ease measurements significantly decreased heat loss, even when forced convection from movement was considered.Originality/valueThis is the first article of its kind to explore the relationship between garment ease and predicted manikin THL, especially for fire service protective clothing. Findings indicate a valid recommendation for turnout gear designers and manufacturers to optimize clothing fit to improve breathability and potentially reduce incidents of heat strain in the fire service.

Dynamic Heat Transfer Simulation in Textile for Practical Application: A Comparative Analysis of Microscopic and Macroscopic Approaches

Heat transfer simulation in textile materials has many practical applications, such as in the design of protective clothing for firefighters, the development of thermal insulation materials, and the optimization of temperature control in textiles for comfort and performance. This paper presents a study on heat transfer simulation in woven fabrics using the Comsol Multiphysics® application. The simulations were carried out for both microscopic (3D) and macroscopic (1D) scales and the heat flux variation was compared with experimental results. The steady-state average heat flow through the textile was determined, and this value was used to calculate the thermal resistance of the woven fabrics. The thermal resistance values obtained were within a deviation range of 4.2% to 6.3% from the values determined according to ISO 11092/1016, thus validating the proposed model. For the transient regime, the microscopic approach proved to be more accurate, the estimated time for the heat flow to reach a certain value depending essentially on the scale approached in the modeling. This finding has particular significance in the field of protective clothing, especially for firefighters exposed to radiant heat sources, where estimating the time for burns to occur is crucial.

Applied research on the design of protective clothing based on the Kano-QFD-PUGH method.

In order to improve the user experience of protective clothing for healthcare workers and reduce the design blindness and subjectivity of developers, we propose a research methodology that combines the Kano model, QFD quality function deployment, and PUGH decision-making scheme to develop conceptual solutions for medical protective clothing design. Firstly, we use the Kano model to identify the user requirements of healthcare workers and construct a hierarchy of functional requirements for protective clothing. Secondly, we use the QFD method to weigh the protective clothing design elements, convert user requirements into design elements, establish a relationship matrix between user requirements and design elements, and generate four conceptual design solutions based on the results. Finally, we use the PUGH decision-making method to filter and select the best concept solution for protective clothing design, and validate the design evaluation. Our results show that the protective clothing solutions designed using the combined Kano-QFD-PUGH system approach have a higher level of satisfaction compared to traditional protective clothing design. This method accurately explores the mapping relationship between user requirements and design functional elements and can be used as a general reliability design method. It helps to improve the development efficiency of designers and the decision-making role for design concept solution preference. Overall, our research methodology provides a comprehensive approach to developing medical protective clothing, which can be useful for designers and decision-makers in the healthcare industry.

Based on ACF-CFRP composite energy absorbing material protection clothing designing for the elderly with degenerative imbalance

With the progression of age, the risk of falls in the elderly population escalates. Hip fractures are perceived as one of the most severe consequences of such falls and are often described as “the last fracture in one’s life,” with mortality rates reaching 20%−30% and accompanied by a significant rate of disability. To address this pressing issue, our study conducted an in-depth analysis of the mechanical properties of Artificial Cartilage Foam (ACF) and Carbon Fiber Reinforced Polymer (CFRP). Based on this research, we devised a laminated structure where ACF acts as the outer layer, with CFRP positioned centrally, capitalizing on the material’s intrinsic shock-absorbing attributes. Building on this structure, based on this structure, a specialized protective clothing design tailored for the elderly to counteract age-related balance impairments is proposed. Furthermore, we undertook experiments to gage user anxiety levels and assess the wearability comfort of the attire. Our findings indicate that this protective garment can effectively absorb the impact energy generated during falls, significantly reducing the risk of injury in the elderly. Additionally, its ergonomic design helps alleviate the psychological distress elderly individuals may experience due to the fear of falling. This research presents an innovative and effective strategy for enhancing fall protection in the elderly demographic.

Recent research developments of textile flexible structures with high puncture resistance: A review

In recent years, with the popularity of firearms and ammunition, body armor materials have undergone a great development. Body armor is commonly used to provide protection against ballistic threats, and its use has increased as people become increasingly aware of protecting their own lives. Compared with the traditional body armor materials, fabrics made of high-performance fibers are not only lightweight and convenient, but also process good protective performance. The purpose of this study is to obtain textiles with higher puncture resistance, by reviewing the progress of rapidly changing and advancing field of high-performance textiles with puncture resistance, which is introduced into four methods: shear thickening fluids (STFs), coating and impregnation, composition and structural optimization, respectively. The content of the manuscript provides a comprehensive perspective for new researchers in relevant fields for subsequent design of protective clothing.

The issue of the development of material package for protective cloth designing

Introduction: The article presents the characteristics of existing materials of top, heat-insulating and lining materials which are used for the design of protective clothing. A number of comparative analyses of the studied materials for further use them as a package in overalls was carried out. Materials and Methods: When writing, various methods were used, such as the comparison method, the historical method, the market analysis method, and others. Results and Discussion: We have researched the various fabrics and non-fabrics produced and used in industry that fall under the category of protective fabrics. Conclusions: As a result of a comparative, bibliometric analysis, it was revealed that a wide variety of different special-purpose materials is currently on the market.

Measuring convection heat transfer coefficients and thermal resistance for protective fabrics using a heated cylinder in a wind tunnel

One tradeoff in design of protective clothing for firefighters and other workers is between thermal protection and thermal stress management. Standard methods for assessing thermal stress management of protective clothing include guarded hot plate and mannequin tests. In this study, a fabric-covered heated cylinder was used in a wind tunnel to measure convection heat transfer coefficients and thermal resistance at various air speeds. Measurements demonstrated the impact of air permeability and wind speed on these parameters. When the cylinder was covered with low permeability fabrics, convection heat transfer coefficients were similar to values predicted using a correlation for bare cylinders. Thermal resistance measurements generally ranked fabrics in the same order as guarded hot plate tests. This cylinder test is more representative of the body’s geometry than hot plate tests, but less expensive to conduct than mannequin tests, and could serve as a bridge between these two tests for design purposes.

Study on Heat Transfer Characteristics and Intelligent Optimization of Protective Clothing Materials in front of the Blast Furnace.

Special protective clothing should have a certain thermal insulation and protective effect in the production in front of the blast furnace. In order to study the design of special protective clothing for blast furnace foreman, its temperature distribution and internal thickness structure are deeply analyzed. First, based on the existing experimental data, combined with heat transfer and the Fourier law theory, a one-dimensional unsteady heat conduction equation is established. Using the explicit finite difference solution algorithm, the distribution law of the temperature of each fabric layer with time is obtained and the error analysis is performed. The error result is 0.42877%, which shows that the numerical solution is stable and convergent. Then, through the intelligent optimization model of a simulated annealing ant colony (SA-ACO), compared with the single ant colony algorithm (ACO) and a simulated annealing algorithm (SA), it avoids falling into the local optimal solution, reversely solves the optimal thickness of two layers of protective clothing in front of the blast furnace, improves the convergence speed of optimization, and verifies the reliability of the model with a sensitivity test. Finally, this paper actually solves the problem of the protective clothing design and mathematical intelligent model in front of the blast furnace and combines it with numerical simulation software to realize the numerical simulation of temperature distribution and thickness optimization of special protective clothing in front of the blast furnace, so as to provide theoretical guidance for enterprise blast furnace production and development of special protective clothing.

A new thermal protective clothing design with silica aerogel filled acrylic nanofibers

PurposeFirefighters are exposed to high outdoor temperature and heat stress caused by metabolic activities during firefighting and should wear protective clothing to ensure their safety and health. Traditional firefighter protective suits are bulky and heavy garments with reduced thermal comfort properties since the fabric thickness and moisture barrier layers prevent heat transfer of the garment and cause additional heat stress. The aim of this study is to reduce heat stress by creating a new fabric design with silica aerogel membrane as a moisture barrier for three-layer fabric system.Design/methodology/approachPolyacrylonitrile (PAN) nanofibers were produced with three different silica aerogel contents and used for three-layered clothing system as a moisture barrier for giving desired protectiveness and thermal comfort to firefighters. Different fabric combinations were designed using two types of outer shell fabrics, two types of moisture barrier fabrics, two types of thermal barrier fabrics and PAN/silica aerogel membranes.FindingsThe results show that a lighter fabric system with improved wearer’s mobility and thermal comfort properties (thermal resistance and moisture permeability) is achieved with the use of PAN/silica aerogel membrane as an intermediate layer compared to commercial thermal protective fabric systems.Originality/valueDifferently from traditional thermal protective clothing, which may not provide adequate protection in long-term heat conditions or when exposed to flash fire, a new thermal protective clothing has been developed to be used in extremely hot environments, providing desired technical and performance properties, ease to wear comfort.

Development of a quantitative system for subjective evaluation of tracked vehicle crew jackets

The purpose of this study is to develop a quantitative evaluation system that reflects the required performance factors that are important for a tracked vehicle crew jacket. We identified and analyzed the necessary performance factors obtained from a focus group interview and a questionnaire survey. Further, we proposed a new method of calculating weights and developed a quantitative evaluation system. This system featured an equation that calculated the evaluation score out of 100, using the factors’ percentages in the total factor as factor weights. The system’s application was verified by the assessment of subfactors by active-duty soldiers, and by confirmation that the results of the developed factor scores reflected the proposed development direction. The study is significant for its provision of a comprehensive and quantitative evaluation system which has not existed before for protective clothing design, as well as for the verification of the system’s application through the process of protective clothing development. The quantitative evaluation system and its development process described in this study may be referenced and widely deployed due to its use of a Likert scale, which is commonly used as a subjective sensory evaluation tool.

Surveying Healthcare Workers to Improve the Design, Wearer Experience and Sustainability of PPE Isolation Gowns

This protective clothing design project responds to the urgent need for research into the redesign of personal protective equipment (PPE) isolation gowns, to be more fit for purpose and reusable to enhance the experiences of healthcare workers treating patients with COVID-19 and variants. Funded by the Arts and Humanities Research Council (AHRC) the research addresses the engineering question: “What new materials, design and manufacturing approaches should we start to consider in preparation for pandemics e.g. reusable PPE to replace single use?” The article focuses on the online questionnaire/ survey, its main findings and the ‘participatory clothing design’ methodology which prioritises the lived experiences and expressed needs of healthcare workers wearing disposable and reusable PPE in acute care scenarios. Research methods include literature and gown reviews, selected interviews and survey directed at nurses, to acquire first-hand qualitative data about the impact of current gown design and procurement policies on wearers. Selected results and commentary from the ongoing survey are presented and thematically analysed to inform the development of reusable gowns. Semi-structured interviews with clinical leads and caregivers, as well as responses from users, will be important to integrate expertise in fashion, textile and uniform design, clinical practice, and manufacturing. Further design will be based on a complex design brief that balances the needs of wearers and critical care providers while considering regulations, protection, comfort, sustainability, and cost. This research focuses on enhancing an overlooked area of critical care clothing and the people who wear it while reducing its detrimental impact on the planet.

REGIONAL AND DIRECTIONAL DIFFERENCES OF THE INTERVERTEBRAL DISC ANNULUS FIBROSUS MECHANICAL PROPERTIES

The loading experienced by military helicopter and fighter aircrew can lead to spinal injury by degrading the soft tissues. Fighter pilots endure low frequency high magnitude loading, while helicopter pilots endure high frequency vibrational loading over longer periods of time. The purpose of this study is to analyze intervertebral disc material properties, including elastic modulus, failure strain, and failure stress. This will provide data to model the annulus fibrosus to predict the risk of injuries. Quantifying the risk to specific spinal locations could provide insight to improve the design of protective clothing and equipment. Single layers of the porcine annulus fibrosus were subjected to tensile failure tests to determine the mechanical properties. Results showed a significantly (p< 0.05) higher elastic modulus in the circumferential direction compared to the axial direction. There was also a significantly greater elastic modulus for samples from the lateral region of the disc compared to the posterior region. There was no significant difference for the anterior region or specimen depth with regards to elastic modulus. Failure stress showed significant differences between superficial and deep specimens as circumferential and axial testing directions. Failure strain only had differences between circumferential and axial directions. This data can be used to help predict where in the disc an injury may occur. Because of the decreased posterior elastic modulus, tensile failure is more likely to occur in that region.

Face shield intensifies inhaled exposure to self-generated bio-effluents

The presence of a face shield may block the forward and upward dilution of bio-effluents, generated from one's own exhalations and skin, through the breathing zone, which might thus intensify the user's inhaled exposure, especially for long-term use. The objective of this study is to quantify this exposure risk. The flow characteristics of the porous region at the top of a typical face shield were tested experimentally. The viscous resistance coefficient and inertial resistance coefficient of the porous region were 4.9 × 107 and −402, respectively. The influence of breathing mode (via mouth and nose), pulmonary ventilation rate (6–8 L/min), and bio-effluents generation location (i.e., exhalation, groin, and armpit) on the exposure risk of bio-effluents were then studied by computational fluid dynamics (CFD) technology in combination with the species transport model. The inhaled fraction (iF) index was used to assess the exposure risk. A face shield can considerably increase the exposure risk, the inhaled fraction index being increased from 0.28% to 2.97% for skin pollutants, and from 2.25% to 6.96% for exhaled pollutants. It means that the fraction of oxygen (O2) in the inhaled air of face shield wearers is 20.58%, being 2% less than that without face shield. For face shield wearers, a higher pulmonary ventilation rate and breathing through nose would further increase the exposure risk. This information would be important boundary conditions for accurate simulation and design of face shield as well as the design of protective clothing.

Definition of the Main Features of Material Assemblies for Thermal Protective Clothing During External High-temperature Effect Modelling

A computational-experimental method of material selection for thermal protective clothing design is proposed in this article. The intended operating temperature of the garment lies within the range of 40−170 °С. The prerequisite for the research was the lack of information regarding changes in the physical-mechanical and ergonomic characteristics of material assemblies during their use under high-temperature conditions. During the initial stage of research, there was a problem associated with the selection of the most important and the exclusion of the least significant indicators, in order to further reduce the number of experimental tests in laboratory and industrial conditions. The authors used the method of expert evaluations to solve the problems related to the selection of the most significant indicators for material assemblies. Material assemblies were formed by varying the combinations of heat-resistant, heat-insulation and lining layers of materials. Initial information for the proposed method was obtained from the experimental tests of sixteen material assemblies. According to the results of the ranking, the main parameters of material assemblies were identified as follows: the temperature range for which the use of clothing is intended, thickness, mass per unit density, rupture resistance, relative tearing elongation, change in linear dimensions during mechanical loads, air permeability and change in assembly thickness during cyclic loads. It was established that the assembly that includes heat-resistant material of the Nomex comfort N.307 220 top, Nomex Serie 100 heat-insulation lining and Nomex TER 135 lining provides the necessary level of protection, reliability and ergonomics, and meets cost requirements.

The Study of Sustainable Strategy in Design of Protective Clothing and Accessories After Coronavirus (COVID-19) Outbreak

During the COVID-19 pandemic, the coronavirus frontline healthcare workers and the public have generated a great demand for personal protective equipment (PPE). According to the assessment of risk level, PPE such as medical masks, protective suits and face shields should be given priority to the healthcare workers and other medical first responders for use. The risk of the public to exposure is much lower than that of healthcare workers, and there is no need to wear such high-risk protective clothing and accessories. In the face of the general shortage of personal protective equipment due to increased demand, panic buying, hoarding and abuse, the public should look for alternative protection solutions when they are at home or going out. In the view of the problems above, this paper refers to the analysis of the current status of sustainable strategies in the design of protective clothing and accessories. It proposes a design method for the upcycle of abandoned clothing and daily objects. From the perspective of functional protection, demountable and modular design, it also provides methods and means for the sustainable optimal design of PPE, such as multi-functional protective hood, demountable design details, multi-pocket hidden design, internally seamed elastic strap structure, strengthened tightening design of the clothing opening. It is designed to help prevent the spread of transmissible viruses and bacteria, thereby protecting self and preventing others from infecting while alleviating the growing demand for PPE during the COVID-19 pandemic.

Heat transfer modeling within the microclimate between 3D human body and clothing: effects of ventilation openings and fire intensity

PurposeThe purpose of this study is to determine the effect of ventilation openings and fire intensity on heat transfer and fluid flow within the microclimate between 3D human body and clothing.Design/methodology/approachOn account of interaction effects of fire and ventilation openings on heat transfer process, a 3D transient computational fluid dynamics model considering the real shape of human body and clothing was developed. The model was validated by comparing heat flux history and distribution with experimental results. Heat transfer modes and fluid flow were investigated under three levels of fire intensity for the microclimate with ventilation openings and closures.FindingsTemperature distribution on skin surface with open microclimate was heavily depended on the heat transfer through ventilation openings. Higher temperature for the clothing with confined microclimate was affected by the position and direction of flames injection. The presence of openings contributed to the greater velocity at forearms, shanks and around neck, which enhanced the convective heat transfer within microclimate. Thermal radiation was the dominant heat transfer mode within the microclimate for garment with closures. On the contrary, convective heat transfer within microclimate for clothing with openings cannot be neglected.Practical implicationsThe findings provided fundamental supports for the ease and pattern design of the improved thermal protective systems, so as to realize the optimal thermal insulation of the microclimate on the garment level in the future.Originality/valueThe outcomes broaden the insights of results obtained from the mesoscale models. Different high skin temperature distribution and heat transfer modes caused by thermal environment and clothing structure provide basis for advanced thermal protective clothing design.

Process Qualification of the Individualization of Protective Clothing Design Based on 3D Scanning Technique

The process of individualizing personal protective equipment (PPE) is aimed at achievingoptimal fit to the user’s body, thus maximizing comfort, especially when PPE is applied in critical conditions. The aim of the research was to confirm the possibility of implementing PPE in rea industrial conditions and to estimate the comfort of use in real conditions of use. In order to perform the last stage of the personalization procedure for firefighter suits, process qualification was carried out in an industrial environment, and the firefighter’s PPE fabricated was validated under real conditions of firefighters’ activities. The effect of implementation of the individualization procedure confirmed optimal fitting of the PPE to the individual user’s body and allowed for improvement of the comfort of use.

Operational Qualification of the Individualisation of Protective Clothing Design Based on the 3D Scanning Technique

The object of the publication is to present the validation process stage (operational qualification) of developed assumptions for customised clothing manufactured in industrial conditions. 12 special clothes were made and adjusted to the individual dimensions of firefighters’ silhouettes obtained in the 3D scanning process as well as 12 special clothes adjusted to selected size subgroups after the 3D scanning process from the same identified group of 12 firefighters. Two batches of clothes having undergone the installation qualification were submitted for testing in real conditions (operational qualification). Then, on the basis of data collected from the ongoing functional tests, a batch of six sets of individualised special clothing for the Fire Service was produced in industrial conditions (changing the manufacturer and model of the clothing). A positive result of validation (operational qualification) of this batch of clothing in functional tests conducted in real conditions will allow its introduction to industry through training in production plants and procedures of individualisation of advanced protective clothing design for people working in environments with a high degree of risk to health and life. The individualisation of protective clothing design, through a better fit of the size of the clothing to the body of the user, will significantly affect the comfort of use, ergonomics of the clothing, and the safety of the user.

Aspects of applying theory of human ecology to design safe heat-protective clothing for the disabled people

The article discusses current theoretical and practical issues of scientific research based on the interaction of environmental and technogenic factors in the development of safe heat-protective clothing models for people with restricted motor abilities. In particular, the main results of studying the interaction of elements and objects belonging to the dynamic system «human – habitat – heat-protective clothes» are presented. The purpose of the work was to justify the choice of structural clothing materials with the help of using obtained analytical information on thermal field formation of under clothing space area. The relevance of the described studies is due to the permanently increased demand for special heat-protective products for the disabled and insufficient knowledge of multi factorial environmental processes in spatio-temporal coordinates. The scientific novelty of the presented work consists in solving the problem based on the analysis of the interaction of human lower limbs and heat protective clothing by means of using the author’s mathematical model. To carry out the research, modern mathematical methods were used, including system analysis, synthesis of alternatives, modeling, generalization and results verification. The obtained materials develop the theory of applied areas of human ecology. The implementation of the above stated recommendations in the practice of heat protective clothing design contributes to a process of people’s socialization with restricted motorabilities.

Optimal design of protective clothing based on difference equation

The temperature distribution and thickness design of high temperature protective clothing are studied in this paper. Based on the data provided by China mathematical modeling competition in 2018. We establish the temperature distribution model and skin layer heat conduction and burn model. The interface continuous conditional difference method, differential iterative method, least squares method and the chasing method are used to solve the given temperature distribution on the protective clothing in the environment, and analyze protective clothing meeting the actual needs.