Development Of Protective Clothing Research Articles

A Comparative Analysis of Thermoelectric Modules for the Purpose of Ensuring Thermal Comfort in Protective Clothing

In recent times, more and more workers are exposed to thermal stress due to climate changes and increased ambient temperature. Demanding physical activities and the use of protective clothing are additional sources of thermal load for workers. Therefore, recent research has focused on the development of protective clothing with a cooling function. Phase change materials, air or liquid, were mainly used for this purpose; only a few publications were concerned the use of thermoelectric modules. This publication analyzes the influence of such factors as supplied current, ambient temperature, and the type of heat sink on the amount of heat flux transferred by a thermoelectric cooler (TEC) and the electric power consumed by it. In the course of laboratory tests, a flexible thermoelectric module and three heat sink variants were tested. For this purpose, a polymer TEGway heat sink, a metal one, and a self-made one based on a superabsorbent were used. The research showed that at a temperature of 30 °C and above, the amount of the heat flux transferred by a TEC with a total area of 58 cm2, and an active area of 10 cm2 should be expected to be from 1 W to 1.5 W. An increase in ambient temperature from 20 to 35 °C caused a significant reduction in the heat flux by about 1 W. The results obtained indicated that the type of heat sink affects the heat flux drawn by the TEC to a statistically significant extent. The heat sink using the evaporation effect turned out to be the most efficient.

Investigation of the stab resistance mechanism and performance of uncoated and SiO2 coated high-performance aramid fabrics

Surface coatings on the fabrics can enhance protective properties of flexible body armors. It is known that the application of coating increases inter yarn friction, however, detailed mechanism of knife-yarn interaction in coated and uncoated fabrics is not fully understood yet. This study investigates in detail the knife-yarn interaction at individual yarn level and role of improved inter yarn friction in enhanced stab resistance of woven aramid fabrics deposited with SiO2 coating. The coated fabric exhibited an increase of 115% in the knife penetration resistance compared with uncoated fabric due to increase in inter yarn friction. The coefficient of friction increased 29% after coating. The video graphicanalysis performed during quasi static stab resistance revealed important insights into the knife to yarn interactions. The filaments within the yarn in the uncoated fabric interact individually with the knife, undergo sequential cutting of filaments and offer less resistance to knife penetration. On the other hand, filaments within the yarn in the coated fabric were found to interact collectively, as cohesive assembly of fibers, undergo simultaneous cutting offering greater resistance to the penetrating knife. The results of yarn pull out, yarn sliding, single yarn cut resistance and single yarn strength tests confirmed that improvement in the stab resistance was attributed mainly to the increased inter yarn friction after coating the fabric while intrinsic properties of the yarn were not altered. The findings of this study will be helpful in the development of protective clothing with improved stab resistance.

A review of the osteoderms of lizards (Reptilia: Squamata).

ABSTRACTOsteoderms are mineralised structures consisting mainly of calcium phosphate and collagen. They form directly within the skin, with or without physical contact with the skeleton. Osteoderms, in some form, may be primitive for tetrapods as a whole, and are found in representatives of most major living lineages including turtles, crocodilians, lizards, armadillos, and some frogs, as well as extinct taxa ranging from early tetrapods to dinosaurs. However, their distribution in time and space raises questions about their evolution and homology in individual groups. Among lizards and their relatives, osteoderms may be completely absent; present only on the head or dorsum; or present all over the body in one of several arrangements, including non‐overlapping mineralised clusters, a continuous covering of overlapping plates, or as spicular mineralisations that thicken with age. This diversity makes lizards an excellent focal group in which to study osteoderm structure, function, development and evolution. In the past, the focus of researchers was primarily on the histological structure and/or the gross anatomy of individual osteoderms in a limited sample of taxa. Those studies demonstrated that lizard osteoderms are sometimes two‐layered structures, with a vitreous, avascular layer just below the epidermis and a deeper internal layer with abundant collagen within the deep dermis. However, there is considerable variation on this model, in terms of the arrangement of collagen fibres, presence of extra tissues, and/or a cancellous bone core bordered by cortices. Moreover, there is a lack of consensus on the contribution, if any, of osteoblasts in osteoderm development, despite research describing patterns of resorption and replacement that would suggest both osteoclast and osteoblast involvement. Key to this is information on development, but our understanding of the genetic and skeletogenic processes involved in osteoderm development and patterning remains minimal. The most common proposition for the presence of osteoderms is that they provide a protective armour. However, the large morphological and distributional diversity in lizard osteoderms raises the possibility that they may have other roles such as biomechanical reinforcement in response to ecological or functional constraints. If lizard osteoderms are primarily for defence, whether against predators or conspecifics, then this ‘bony armour’ might be predicted to have different structural and/or mechanical properties compared to other hard tissues (generally intended for support and locomotion). The cellular and biomineralisation mechanisms by which osteoderms are formed could also be different from those of other hard tissues, as reflected in their material composition and nanostructure. Material properties, especially the combination of malleability and resistance to impact, are of interest to the biomimetics and bioinspired material communities in the development of protective clothing and body armour. Currently, the literature on osteoderms is patchy and is distributed across a wide range of journals. Herein we present a synthesis of current knowledge on lizard osteoderm evolution and distribution, micro‐ and macrostructure, development, and function, with a view to stimulating further work.

Finite element modeling and simulation of hip joints in elderly women: for development of protective clothing against fracture

PurposeFracture experiments on real human bodies to examine the protected positions and protective devices for the development of protective clothing to manage fractures is exceedingly difficult. Thus, the experimental design will have limitations, more of which are imposed if subjects are elderly people. To circumvent these limitations, this study proposes a finite element model of the hip joint in elderly women with virtual impact simulations that can replace actual fall and impact tests, and examine the positions and characteristics of fractures resulting from taking a fall.Design/methodology/approachThe hip joints were modeled after the average horizontal surface size and cross-sectional shapes of the lower extremities (waist to knee) in 439 elderly Korean women in that age group. The model was composed of bones, cartilages, and soft tissue.FindingsThe fracture was examined by comparing the maximum stress on the hip joint by applying a point force to its adjacent surface. The vulnerable part in the hip joint neck with a high risk of fracture risk on an impact could be determined and used to set the protective device attachment position.Originality/valueIt is significant that this study has developed a partial model of the human body that can be used for a relatively simple simulation by minimizing the highly complex human body as much as possible. Furthermore, the model is easily applicable to the designing of protected positions and protective devices for the development of special clothing, for hip joint fracture prevention.

Utilization of Rice Straw as a Source of Biomolecules for Sustainable Multifunctional Finishing Vis a Vis Dyeing of Wool

ABSTRACT Rice straw is a rich source of biomolecules which can be utilized in functionalization of textile fibers. In the present work, rice straw extract was utilized in functional coloration of wool fabric. The dyed wool samples were characterized by EDX, SEM, TGA and FTIR spectroscopy. The dyed wool fabrics were assessed for color parameters, fastness, antibacterial activity, UV protection, and flame retardant properties. The results showed that dyeing with rice straw extract in the presence of inorganic metal salts produces different elegant hues with acceptable fastness properties. Wool samples dyed with mordant ions also demonstrated potent antibacterial activity against S. aureus, high UV protection, and flame retardant effects. Our results clearly pointed out that rice straw extract could be used as an inexpensive yet effective textile dye and would be a feasible alternative for some synthetic agents in the development of protective clothing for various end uses.

Characterization based on the thermal capabilities of metallized fabrics equipped with hybrid conductive yarns for protective clothing

Electronic textiles are recognized for their conductive characteristics in various fields of research including medicine, communications, power and for the development of protective clothing. Out of the several types of conductive textile available, multi-component yarns and fabrics, produced from continuous copper filament as spiral covering on hybrid cover yarns, have never been investigated for their thermal capabilities. In this study, characterization based on the thermal properties for conventional copper core yarn’s fabric and newly developed copper cover yarn’s fabrics was carried out. The results demonstrate better conductivity of copper cover yarn’s fabrics as compared to the copper core conventional fabrics, which is attributed to its better conduction due to greater percentage of copper and direct contact between the heat flux transducers. With the higher porosity values for the newly developed fabric, the liquid water, water vapour and air transport capabilities, which are key aspects of thermal comfort, significantly improved.

Development of Protective Clothing against Nanoparticle Based on Electrospun Nanofibers

In this paper, the development of efficient protective clothing against nanoparticulate aerosols is presented. Nanofibrous mats of polyamide 6 (PA6) were deposited onto a nonwoven viscose substrate by electrospinning technique. The influence of electrospinning parameters, including solution concentration, viscosity, and conductivity, was studied for the production of nonwovens with controlled fiber diameter showing a size distribution ranging from 66 to 195 nm. By varying several process parameters, textiles with different thickness of the nanofiber layer and thus air permeability were obtained. A hot‐press lamination process using a thermoplastic resin as glue was applied to improve the adhesion of the nanofiber layer onto the textile support. After 1500 cycles of repeated compression and torsion, the nanofiber layer was still firmly attached to the support, while mechanical damage is visible in some areas. The penetration of NaCl particles with diameter ranging from 15 to 300 nm through the electrospun textiles was found to be strongly dependent on nanofiber layer thickness. A really thin nanofiber coating provides up to 80% retention of 20 nm size particles and over 50% retention of 200 nm size nanoparticles. Increasing the thickness of the nanofiber mat, the filtration efficiency was increased to over 99% along the whole nanoparticle range. The results obtained highlight the potential of nanofibers in the development of efficient personal protective equipments against nanoparticles.

Museum Musings

Continuing our series which gives brief glimpses of some of the items in the IBRA Historical Collection. In this issue Executive Director, Sarah Jones looks at aspects of the development of protective clothing.

Ideengeber Holz – ein Überblick | Wood: a provider of ideas – an overview

Owing to its durability, load capacity, wide-ranging dimensions and manifold variations wood is an exemplary prototypical material and an excellent provider of ideas. This article gives an overview on both existing and possible implementations. Examples, such as reinforced concrete or bicycle valves, show an unconscious imitation of «wood inventions» like cell wall structure or bordered pits. Moreover, proper adaptations of wood principles have also been used in the development of protective clothing, wood ceramics and in a self-regulating shape adaptation of components. In addition to these successful adaptations, we present new research projects on the structure principles of wood.

U.S. coast guard research and development program for hazardous chemical discharge response

The U.S. Coast Guard's Office of Research and Development is presently conducting a program to develop equipment and methods for responding to discharges of hazardous chemicals into the waters of the United States. The program to ameliorate hazardous chemical discharges has been divided into six project areas. This paper will provide an overview of these six project areas as follows: 1. Prevention and Reduction: The development of techniques to prevent or reduce the discharge of a hazardous chemical. 2. Personnel Protection: The development of protective clothing, life support systems and personnel monitors for personnel responding to chemical discharges. 3. Detection, Identification, and Quantification: The development of techniques to allow response personnel to detect, identify and determine the concentration of hazardous chemical discharges. 4. Hazard Assessment Modeling: The development and refinement of mathematical models to predict the behavior of discharged hazardous chemicals. 5. Containment, Treatment, and Recovery: The development of hardware and methods to respond to a discharge and mitigate its environmental damage. 6. Disposal: The development of methods to dispose of chemicals which have been recovered. When completed, each of these project areas should provide the Coast Guard with additional capability to respond to hazardous chemical discharges.

Development of protective clothing, protective shoes, and means for the protection of individuals working in the glass industry

Development of protective clothing, protective shoes, and means for the protection of individuals working in the glass industry