Thermophysiological Properties Research Articles

Influence of the Structure of 3D Woven Fabrics on Radiation Heat Resistance and Thermophysiology Properties

The goal of this study was to investigate the influence of structural and constructional parameters of 3D fabric on two of the most significant properties of fabrics for thermal protection—resistance to radiation heat and thermophysiological properties. Today’s textile materials provide high thermal protection, but they display poor thermophysiological properties in extreme conditions. Six samples of 3D fabrics were developed using a laboratory weaving machine. The examined samples were made of identical warp, with a total of three different weft densities, and were woven in two different weaves. The conditions of the weaving process and construction were the same. EN ISO 6942:2022 and EN ISO 11092:2014 methods were used to determine the resistance of the samples to thermal radiation and thermophysiological properties. The results showed that the samples that contained folds in their structure with a larger volume of “trapped” air had better thermophysiological properties and better resistance to thermal radiation. The volume of air contained in the 3D structure was used as a thermal insulator and it did not have a negative effect on the thermophysiological properties. The described structure enabled the 3D fabric to have an optimal ratio of thermal protection and comfort, which is of crucial importance for fabrics used to make thermal protective clothing.

Statistical study and investigation of the cut-resistant and thermo-physiological performance of protective gloves: a new prospective

Objectives. This research investigated the performance properties of protective gloves alongside improvement in thermo-physiological comfort properties. Methods. Knitted gloves prepared from filament stainless steel, filament Kevlar, staple spun Kevlar and filament glass were used in the core, while 100% viscose rayon and 50/50% polyester/viscose rayon were used in the sheath. Gloves were tested for cut resistance, tear resistance, puncture resistance and abrasion resistance as the prime focus, and thermo-physiological comfort properties were also tested. In this research, a multi-response optimization technique, i.e., principal component analysis, was applied to identify the best yarn combination for gloves based on the aforementioned properties. Thermal images were also taken in constant ambient conditions for temperature distribution maps across the hand’s surface. Results. All of the results were evaluated statistically with analysis of variance, and concluded that the effects of the core yarn on thermo-physiological properties were less significant. Conclusion. The results revealed that samples having dual-core yarn exhibited better in terms of overall properties. The sample having dual-core filament Kevlar and staple spun Kevlar ranked the best. In addition, developed samples exhibited better comfort properties than the control sample.

Effect of membrane morphology on the thermo-physiological comfort of outdoor clothing

This article examines the effect of membrane type and its morphology on the chosen thermo-physiological properties of the middle layer of outdoor clothing. In total four different membranes were selected for the production and analysis of three-layer laminates, which could replace the second and third layers of layered clothing for sports/outdoor purposes. As an outer and lining material a polyester knitted fabric with fleece was chosen, whereas the lamination technology was used to join the individual layers. Chosen properties affecting the thermo-physiological comfort of the laminates were evaluated, to be able to select a membrane that, in combination with the outer and inner layer, enabled the use of laminate as an upper clothing layer – a jacket, thereby replacing the necessity of using a second clothing layer. The following properties were chosen as crucial: thermal resistance, air permeability, vapor permeability (water vapor penetration), and hydrostatic pressure resistance. The utility value methodology was used to evaluate individual fleece-based laminates. For the completeness of this study, two types of commercially available three-layer laminates containing soft-shell fabric as the top layer were incorporated for comparison.

Role of fibre, yarn and fabric variables in engineering clothing with required thermo-physiological properties

Role of fibre, yarn and fabric variables in engineering clothing with required thermo-physiological properties

Structural and Physiological Properties of Footwear Textiles

Abstract Textile uppers in the form of fitted knitted fabrics are now gaining in importance in the production of commercial footwear. The subject of this study was twelve different textile uppers and two reference leather materials. Structural properties and parameters of physiological comfort were characterized for selected variants. In order to analyze the thermo-physiological properties of the upper parts of the footwear, air permeability, thermal insulation properties, water vapor permeability and sorption properties were measured. Among the variants of textile uppers analyzed, the most desirable functional properties were shown by knitted fabrics made on cylindrical crochet machines of large diameters. The varnished cowhide leather variant was characterized by the worst hygienic properties.

A Review Paper on Designing of Knee Support System for Elderly People

Knee pain can now occur in people as young as their 30s, not just in their 60s and 70s. As the elderly population grows, hospitals will have a hard time accepting more patients due to the high demand for services. The focus will shift from post-accident care to preventative care, especially for people with knee pain. The first step in designing and developing a successful knee exoskeleton is to conduct high-quality research on the following topics: knee structure, the diseased state of osteoarthritis, knee kinematics, gait analysis, the existing market for knee exoskeletons, actuation methods, novel software, sensors, and more. The study found that applying heat to the knee increases tissue temperature, softens surrounding tissues, reduces tissue viscosity, increases connective tissue extensibility, reduces pain, and increases joint mobility. Flexible sensors are used in wearable devices such as electric skin, flexible strain gauge sensors, motion detectors, and self-repairing sensors. A self-adjusting knee joint is being developed to allow passive self-alignment with the ICR of the natural knee. Neoprene rubber is a synthetic closed-cell rubber used in medical devices, but it lacks breathability and restricts the movement of water vapor, moisture, and heat. Knitted stretch fabrics provide warmth and compression to injured areas, and foam provides shock protection and pressure points to promote healing. Test methods are used to evaluate the dimensional, mechanical, and thermo-physiological properties for material selection. A wearable suit design was studied using a Design of Experiments approach, with eight key parameters identified and an optimization method developed. Robotics and automation technology were used to address discomfort issues in the body-worn knee exoskeleton design.

A study on the effect of material type, structure tightness and finishing process on the physical and thermo-physiological properties of sandwich terry socks for winter wear

Compared to other textiles, socks are made at the lowest cost and have the highest consumption rate, making them one of the least-lasting fabric goods in the clothing industry. Socks are available in a wide range of fibers blends, that is, cotton, wool, nylon, acrylic, polyester, olefin, spandex, etc. As an element of footwear, socks act in tandem with the foot and shoe, influencing the temperature and moisture levels of the feet. The comfort of clothing next to the skin in terms of temperature and moisture is gaining more and more attention. Pilling is a serious issue with wool items, and less pilling is required since it negatively impacts the esthetic, comfort, and longevity of the fabric. This research has investigated socks pilling tendency and thermo-physiological comfort properties, that is, air permeability and thermal resistance made by wool/polypropylene blend yarn. Three different combinations of wool/polypropylene yarns on the main and platting side of the socks were used at two different tightness levels. Polyurethane finish has been applied to check the socks’ behavior after the finish application. Statistical analysis showed that finished samples knitted with wool/polypropylene as a main yarn offer the best results against the pilling test while sample code ANL, an unfinished sample, offers the best results regarding air permeability, thermal resistance, and overall moisture management capacity.

Development and characterization of socks with improved anti-odour, thermo-regulating and handle properties

Due to awareness of the potential threats of spreading diseases, the demand for antimicrobial fabrics in the world market has grown significantly and, is, expected to increase the share of medical textiles in the future world market. The purpose of this study is to develop antibacterial socks with the application of silver particles and to study thermo- physiological properties as well as the evaluation of tactile sensory perceptions of treated socks against untreated socks. Socks, which are a necessary item of clothing, need to be comfortable and affordable. The materials used for this study are cotton and polyester fibre with three different cross-sectional shapes i.e., common Polyester (round shape), Coolmax (Channeled polyester) and Thermolite (Hollow polyester). Blend ratios with percentages of 80/20 Cotton/Polyester, 80/20 Cotton/Coolmax and 80/20 Cotton/Thermolite were used as main yarns in plain crew socks while elastane yarn is used in the same percentage in all developed socks. A comparison between the samples treated with silver particles and the corresponding control samples concerning the selected properties was done. The presence of particles on the treated fibre was confirmed through an SEM study. Testing of untreated and treated fabrics for antibacterial study and odour test was carried out and found significant. The thermo-physiological properties such as air permeability, relative water vapour permeability % and thermal resistance were also studied and found better results as compared to untreated samples. Later tactile sensorial comfort i.e., fabric hand value was compared which is improved for treated samples which makes the wearer comfortable hand feeling. These data present a great interest to socks manufacturers who can make better choices to manufacture, cost-effective anti-odour socks.

Multifunctionality of Thermal Protective Layer Interchanging Double Cloth Conditioned by Influential Parameters.

The proportion of woven fabrics in the broad field of protective textiles is extremely high. By various procedures (surface treatments, fabric lamination, composite production), fabric properties that meet the requirements defined by standards are achieved. However, simultaneously, these procedures cause negative effects in the form of fabric thickness, stiffness, impermeability, non-breathability, and thus, discomfort. Therefore, there are valid and justified reasons to approach the design process of making such woven fabrics using more complex construction solutions-layer interchanging double cloth. In addition, by applying fibres with integrated desired properties and other structural fabric parameters, it is possible to influence the achievement of the properties of multi-purpose multilayer fabrics for protection, which is the aim of this research. The application and combination of aramid and modacrylic/cotton fibres and use of different yarn fineness resulted in different intensities of protection. The correlative values of mentioned parameters and thermal and thermo-physiological properties indicate their strong connection, and thus the effectiveness of the developed woven fabric samples.

A critical review on prediction of functional & performance attributes of textiles by artificial neural network

Prediction of functional and performance properties of textiles before the actual commencement of fabric production and testing can serve as an effective tool in characterization and designing of fabrics for any desired application. The thermo-physiological properties of textile materials can be predicted by a variety of models, such as statistical, mechanistic and artificial neural network models. Statistical models can give good prediction performance, provided a large data set is presented to make the model and relationship exists between input parameters and response variables. The effect of input parameters on thermo-physiological properties of fabrics cannot be studied in isolation, owing to interdependence and nonlinear relationship of parameters with each other. Statistical models fail to present satisfactory analysis of relationship in such cases. Mechanistic models are useful tools in understanding the fundamentals and physics involved in heat, moisture and liquid transfer through textiles. However, the assumptions considered in the simplification of mechanistic models may not be valid in all conditions and can lead to high prediction errors in real conditions, owing to inherent variability in the textile structures. Moreover the model becomes more complicated as the number of parameters and assumptions increase, thereby limiting the model’s accuracy of prediction. Artificial neural network is a powerful and potent modelling tool which can understand any complex relationship between input and response variables and predicts the thermo-physiological properties of fabrics by considering all fabric parameters at a time. The network exhibits the ability of simulating the functioning of a biological neuron and, in turn, each network component poses analogy to the actual constituents or operations of a biological neuron. In this study, an attempt has been made to highlight the significance of artificial neural network in prediction of comfort properties of textiles.

4D-textiles: development of bistable textile structures using rapid prototyping and the bionic approach

PurposeThis study aims to propose a new methodology to develop bistable textile structures with two different states of heat and moisture transfer by taking inspiration from the animal kingdom. Bionic approaches controlling thermoregulation were analyzed, implemented at the textile level and evaluated. Therefore, 4D technology has been applied. This paper presents all the steps necessary for transferring bionic concepts on the textile level by using rapid prototyping and the 4D-textile approach.Design/methodology/approachConcepts for thermoregulation are derived from bionic approaches and are evaluated by the metrics of low cost and high adaptability to quickly changing needs. Subsequently, bionic approaches were implemented as prototypes by printing on a pre-stretched textile using an fused deposition modeling printer. The printed patterns and properties were investigated, and the effects of each parameter were evaluated. Finally, the prototypes were tested by comparing the data from the thermal imaging camera of the two bistable states.FindingsThis paper presents two printing pattern concepts for creating textiles with two different states of thermal and moisture transfer. The results show that bionic approaches for thermoregulation transferred to the textile level are possible and quickly put into practice through 3D-printing technology as a tool for rapid prototyping.Originality/valueThe presented methodology fills the technological gap for quickly transferring bionic approaches to the textile level using the 4D-Textile technology. In addition, the possibility of generating two bistable states with different thermophysiological properties in one textile and switching between them easily was shown.

Thermophysiological properties of bovine leather in dependence on the sampling point, tanning and finishing agents

The influence of differently tanned and finished bovine leather on thermophysiological properties was investigated. In addition, it was investigated whether sampling has a significant influence on the thermophysiological properties. The back of the tested leathers is thicker than the neck because of better microstructure regularity and uniformity as well as thicker and denser distributed fibrils than in the neck parts. The neck parts have a greater proportion of air-filled spaces between the fibrils, resulting in a higher thermal resistance of the leather neck parts. Considering the thickness of synthetic and chrome-tanned leathers (dyed and hydrophobized), the thinner chrome-tanned leathers (0.063 W m−1 °C−1 for the neck part, 0.090 W m−1 °C−1 for the back part part) have almost the same thermal conductivity as synthetic ones (0.065 W m−1 °C−1 for the neck part, 0.089 W m−1 °C−1 for the back part). Their thermal and water vapour resistance show considerable differences. There is no significant difference in water vapour resistance of the neck and back part of chrome tanned, dyed and hydrophobized leather (25.27 m2 Pa W−1 for the neck part; 25.15 m2 Pa W−1 for the back part) in contrast to equally treated synthetically tanned leather (30.38 m2 Pa W−1 for the neck part; 26.96 m2 Pa W−1 for the back part).The presented study could help in choosing the appropriate point of sampling, tanning as well as finishing agents for obtaining satisfying thermophysiological comfort in the wide range of leather application.

Comparative Study on the Water Vapour Permeability of Textile by a Standard and Novel device

Thermo-physiological properties are very much connected to water vapour and air permeability. There are multiple standards with different working principles to determine the exact performance of any textile material. However, most of these tests are time-consuming and work on the steady state principle, whereas few devices work on heat flux, where results can be obtained much more quickly. The research article covers the testing of 8 unique shirt samples on these devices compared that on a novel device created by the author to see how much the results differ from each other. Lastly, a theoretical approach was used to determine any correlation between air permeability and water vapour permeability. The research work helps in understanding the working of different devices used for water vapour permeability and allows a reduction in time by using a predictive approach with just the results from the air permeability machine.

Thermo-physiological properties of polyester chenille single Jersey knitted fabrics

This article sheds light on the important construction parameters of chenille yarn that characterize chenille single Jersey knitted fabric thermo-physiological properties. The study investigates the influence of selected yarn and fabric construction parameters, namely yarn twist, pile height of chenille yarn and loop length on the geometrical, physical and, thermo-physiological properties of chenille outerwear used in cold climates. Moreover, the effect of yarn and fabric parameters on the fabric abrasion resistance was studied as it is one of the main fabric defects. Furthermore, the study optimizes the knitted chenille fabric thermal properties to find out the most suitable for winter knitted outerwear. So, 40 tex chenille yarns were produced at 700 and 850 twist per meter and three levels of pile height, 1, 1.2, and 1.5 mm. Eighteen single Jersey knitted fabric samples were produced at three different loop lengths 1, 1.2, and 1.4 cm. Results revealed that the most prominent factor that influences the tested fabric properties at the given setting range is the fabric loop length followed by chenille yarn pile height then the chenille yarn twist level. As pile height and twist increase, the thermal resistance and conductivity increase while air permeability and water vapor resistance decrease.

Thermo physiological comfort of single jersey knitted fabric derivatives

The main aim of this study is to determine the thermo-physiological comfort properties of single knit fabrics and their derivatives. As the Single Jersey knitted fabrics are the most widely used fabrics in the apparel sector, they have been selected for the analysis purpose. Derivatives of single jersey are developed and compared in order to understand the influence of structural variations. Physical properties e.g. thickness and areal density were evaluated for all knitted fabrics with 100% cotton yarn having three different yarn linear densities and after different stages of relaxation. Various thermo-physiological properties have been studied by changing the combed cotton yarn linear density as well as the structure of single knit fabric. Air permeability, thermal insulation and relative water vapor permeability of the fabrics were observed and investigated under wet relaxed states. It is determined that fabric physical properties are affected by changing yarn linear density and by the dry or wet relaxation stages. The percentage/number of tuck stitches (NTS), location of tuck stitches (LTS) and ratio of tuck to knit stitches (RTKS) have strong influence on physical and thermo-physiological properties of single knit fabrics, even though other knitting parameters remained the same.

Optimization of thermo - physiological properties of structurally modified wool/polyester blended fabrics using desirability function

The thermo-physiological properties of handloom fabrics produced with or without modified wool/polyester yarns in the weft has been studied. Yarn samples at different blend compositions are prepared according to mixture design at a different percentage of fibres using design expert software. The effect of percentage of different fibres, namely polyester, wool and PVA, on different thermo-physiological properties along with fabric properties obtained for different fibres after the dissolution of PVA component at yarn stage or fabric stage have also been studied. This paper also reports the potential of different fibres optimization to achieve maximum desirability for different thermo-physiological properties of treated (at yarn stage and fabric stage) and untreated fabrics with the help of desirability function. Treated fabrics at both stages show better thermo-physiological comfort properties as compared to untreated fabrics. In general, after dissolution of the PVA component both at the yarn stage or at the fabric stage, the treated fabric gives a higher value of thermal resistance, compressibility, drying capacity and water vapour permeability, while a lower value of air permeability and bending rigidity in comparison with untreated fabrics. Results of optimization for treated (at yarn stage and fabric stage) fabrics show higher overall desirability that can be achieved by using less percentage of wool fibres in case of treated fabrics (either at yarn stage or fabric stage).

Comparative Analysis on Thermo-physiological Behavior of Eri Silk, Wool and Bamboo Knitted Fabrics Toward Sportswear

ABSTRACT Layered fabrics are utilized for the development of active sport wear applications due to their thermo-physiological properties. In this study, nine different types of knitted fabrics were developed using mill spun yarns of Eri silk, Wool (worsted), and Bamboo with three different knit structures such as single jersey, single pique, and honeycomb. The thermo-physiological properties such as thermal conductivity, thermal resistance, thermal absorptivity, air permeability, and water vapor permeability were studied. Further to this, the moisture management properties such as wetting time, absorption rate, spreading speed, and maximum wet radius of the knitted fabrics were measured. Finally, the overall thermal comfort fabric was compared both subjective and objective manner and found that Eri silk based knitted honeycomb structure was highest rated than other samples.

Thermo-physiological Clothing Comfort of Wool-Cotton Khadi Union Fabrics

ABSTRACT Khadi is a handspun and handloom woven textile fabric made up of natural textile fibers, predominantly cotton and wool. Khadi mainly intended for apparel purposes. Hence, the thermo-physiological properties of wool-cotton blended khadi fabric are crucial in studying fabric comfort. In this study, the 18 types of wool-cotton blended khadi fabrics are produced on a handloom by using wool-cotton blended yarn as warp; and woolen yarn comprised of three different mixes of Australian Merino (AM) wool and JK crossbred (JKC) as weft yarn. Two different weft yarns of 41.7 and 31.2 Tex were prepared using these mixes. The thermo-physiological properties of fabric viz. air permeability, water vapor transmission, and thermal resistance were studied. The air and water vapor permeability, and thermal resistance of wool-rich blended fabrics were found higher compared to cotton-rich blends. The air permeability is negatively influenced by the fabric cover factor. The coarser weft yarn gives higher air permeability while lower water vapor permeability. The thermal resistance is found to have a positive relationship with fabric cover factor. The wool content in yarn and weft yarn linear density largely influences the thermo-physiological comfort properties of the khadi fabric.

Effect of Lycra Weight Percent and Loop Length on Thermo-physiological Properties of Elastic Single Jersey Knitted Fabric

Abstract The aim of this work is to estimate the effect of loop length and Lycra weight percent (Lwp) on the geometrical and thermo-physiological comfort of elastic plain knitted fabric. Fifty single jersey knitted fabric samples were produced at five levels of Lycra weight percent (Lwp) (4%, 5%, 6%, 7%, and 8%) and loop length (2.7 mm, 2.9 mm, 3.1 mm, 3.3 mm, and 3.4 mm) with full plaited (fp) and half plaited (hp) of bare Lycra. The thermo-physiological comfort properties (thermal conductivity, absorptivity, and water vapor permeability), air permeability, and geometrical properties were measured at standard of each one. The results showed that the elastic single jersey knitted fabric thickness ranged between 3.12 times and 4.2 times of the yarn diameter (d). The fabric thickness increased when loop length is increased and decreased when Lwp is increased. The thermal conductivity, absorptivity, and water vapor resistance (WVR) decreased with Lwp increasing.

Mosquito-Textile Physics: A Mathematical Roadmap to Insecticide-Free, Bite-Proof Clothing for Everyday Life

Simple SummaryMosquitoes can bite across clothing and transmit disease. This is prevented with pesticides applied to clothing. We developed non-insecticidal cloth and garments that provided 100% protection, were comfortable and look-like and feel-like regular clothing.Garments treated with chemical insecticides are commonly used to prevent mosquito bites. Resistance to insecticides, however, is threatening the efficacy of this technology, and people are increasingly concerned about the potential health impacts of wearing insecticide-treated clothing. Here, we report a mathematical model for fabric barriers that resist bites from Aedes aegypti mosquitoes based on textile physical structure and no insecticides. The model was derived from mosquito morphometrics and analysis of mosquito biting behavior. Woven filter fabrics, precision polypropylene plates, and knitted fabrics were used for model validation. Then, based on the model predictions, prototype knitted textiles and garments were developed that prevented mosquito biting, and comfort testing showed the garments to possess superior thermophysiological properties. Our fabrics provided a three-times greater bite resistance than the insecticide-treated cloth. Our predictive model can be used to develop additional textiles in the future for garments that are highly bite resistant to mosquitoes.