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The human body constantly produces thermal electromagnetic radiation with a maximum of about 10 μm. This thermal radiation has a number of positive effects on the human body and, in addition, allows the insulation under clothing to be improved under extreme climatic conditions, causing a significant reduction in ambient temperature. With so-called far-infrared (FIR) textiles, it is possible to ensure the reflection of thermal radiation back to the human body. In the first part of this review, the generation of heat by the human body and its propagation by radiation through the skin are comprehensively explained. The thermal characteristics of the individual skin layers as an emitter of infrared radiation are given. The second part discusses the basic preparation methods of FIR textiles. Suitable particle systems are described based on metals and their oxides, porous carbon, and special ceramics. Modification of the fiber phase (especially the fineness of the fibers and the porosity of the fabric) in combination with the surface coating of metals is also used for their health-promoting effects. The main manufacturers of FIR textiles and their typical products are mentioned.

In this study, an algebraic model and its experimental verification was carried out to investigate the effect of moisture content on the heat loss that takes place due to conduction of sock fabrics. The results show that increasing moisture content in the studied socks caused a significant increase in their conductive heat loss. Plain knitted socks with different fiber composition were wetted to a saturated level, and then their moisture content was reduced stepwise. When achieving the required moisture content, the socks samples were characterized by the Alambeta testing instrument for heat transfer. Three different existing modified mathematical models for the thermal conductivity of wet fabrics were used for predicting thermal resistance of socks under wet conditions. The results from both ways are in very good agreement for all the socks at a 95% confidence level. In the above-mentioned models, the prediction of thermal resistance presents newly a combined effect of the real filling coefficient and thermal conductivity of the so-called “wet” polymers instead of dry polymers. With these modifications, the used models predicted the thermal resistance at different moisture levels. Predicted thermal resistance is converted into heat transfer (due to conduction) with a significantly high coefficient of correlation.

Nonwoven fabrics are widely used for thermal insulation and sound absorption purpose in construction and automobile fields. It is essential to investigate their thermal conductivity and sound absorption coefficient. Five cross-laid nonwoven fabrics are measured on the Alambeta device and Brüel & Kjær impedance tube. Bogaty and Bhattacharyya models are selected to predict the thermal conductivity, and Voronina and Miki models are used to predict the sound absorption coefficient. The predicted thermal conductivity shows a significant difference compared with the measured values. It is concluded that Bogaty and Bhattacharyya models are not suitable for high porous nonwoven fabric. In addition, the results of Voronina and Miki models for sound absorption prediction are acceptable, but Voronina model shows lower mean prediction error compared with Miki model. The results indicate that Voronina model can be used to predict the sound absorption of cross-laid nonwoven fabric.

By applying the simultaneous corona-temperature treatment, the effect of electret temperature on the structure and filtration properties of melt-blown nonwovens was investigated. Fiber diameter, pore size, thickness, areal weight, porosity, crystallinity, filtration efficiency, and pressure drop were evaluated. The results demonstrated that some changes occurred in the structure of electret fabrics after treatment under different temperatures. In the range of 20°C~105°C, the filtration efficiency of melt-blown nonwovens has a relationship with the change in crystallinity, and the pressure drop increased because of the change in areal weight and porosity. This work may provide a reference for further improving filtration efficiency of melt-blown nonwovens.

Thermal performance of aerogel-embedded polyester/polyethylene nonwoven fabrics in cross airflow was experimentally studied by using a laboratory-built dynamic heat transfer measuring device in which the fabric could be applied on a heating rod. Experiments were performed with different airflow velocities and heating conditions. The temperature–time histories of different materials were collected and compared. The temperature difference and convective heat transfer coefficient under continuous heating were analyzed and discussed. Results showed that under preheated conditions, the aerogel-embedded nonwoven fabrics had very small decrease in temperature and good ability to prevent against heat loss in cross flow. As for the continuous heating conditions, the heat transfer rate of each material showed an increasing trend with increase in the Reynolds number. The aerogel-treated nonwoven fabric with the least fabric thickness and aerogel content delivered a significantly increased heat transfer rate at higher Reynolds number. Thicker fabrics with higher aerogel content could provide better insulation ability in cross flow.

In this study, polypropylene meltblown nonwoven fabrics with different structure parameters such as fiber diameter, pore size, and areal density were prepared by the industrial production line. The morphology of meltblown nonwoven fibers was evaluated by using scanning electron microscope, and the diameter of fibers was analyzed by using image-pro plus software from at least 200 measurements. The pore size of nonwoven fabric was characterized by a CFP-1500AE type pore size analyzer. The filtration efficiency and pressure drop were evaluated by TSI8130 automatic filter. The results showed that the pressure drop of nonwoven fabrics decreased with the increase in pore size; the filtration efficiency and the pressure drop had a positive correlation with the areal density. However, when the areal density is in the range of 27–29 g/m2, both filtration efficiency and pressure drop decreased with the increase of areal density; when the areal density was kept constant, the filtration efficiency decreased as the pore size decreased; when the pore size of the meltblown nonwoven fabric is less than 17 μm, the filtration efficiency increased as the pore diameter decreased; when the pore diameter of the nonwoven fabric is larger than 17 μm. In a wide range, the pressure drop decreased as the fiber diameter decreased.

Polyvinylidene fluoride (PVDF) fibrous membranes with fiber diameter from nanoscale to microscale were prepared by electrospinning. The structural parameters of PVDF fibrous membrane in terms of fiber diameter, pore size and its distribution, porosity or packing density, thickness, and areal weight were tested. The relationship between solution concentration and structural parameters of fibrous membrane was analyzed. The filtration performance of PVDF fibrous membrane in terms of air permeability and filtration efficiency was evaluated. The results demonstrated that the higher solution concentration led to a larger fiber diameter and higher areal weight of fibrous membrane. However, no regular change was found in thickness, porosity, or pore size of fibrous membrane under different solution concentrations. The air permeability and filtration efficiency of fibrous membrane had positive correlations with pore size. The experimental results of filtration efficiency were compared with the predicted values from current theoretical models based on single fiber filtration efficiency. However, the predicted values did not have a good agreement with experimental results since the fiber diameter was in nanoscale and the ratio of particle size to fiber diameter was much larger than the value that the theoretical model requires.

Quality is the essence of any product for consumer satisfaction. However, different people have different perception of quality. Eventually the definition of quality varies from product to product and thus it is much more complex in textile clothing material evaluation. The end use application of a specific clothing material determines what should be the parameters of quality evaluation. Thus, the evaluation based on subjective assessment becomes unpredictable and unquantifiable. Quality for dress materials is not simply a physical parameter but something called as psycho-physical parameter. In recent times, many objective evaluation systems have been developed to evaluate the apparel grade textile materials with regard to their quality parameters. However, the evaluation does not involve enough statistical treatment of data so as to obtain a parametric weighted characterization of complex quality. The current work deals with parametric approach to complex quality evaluation based on multicriteria decision-making approach for ladies dress materials. The ladies dress materials are of numerous varieties and choices across the globe. The selection and marketing of these kinds of textile materials need to be given proper emphasis as it depends not only on physical parameters but also on climate, geography, ethnic group, market trend, age group, gender, and many such complex parameters, which are not quantifiable in absolute terms. In this study, woven fabrics used for ladies dress materials are collected from the market and they were evaluated for the consumer-oriented property parameters. A parametric approach is adopted to quantify the overall quality of these dress materials. Various objective techniques were used to evaluate the comfort and esthetic parameters. A complex quality index (CQI) was estimated with weighted combination of all the contributing parameters and total quality index was calculated. Selected consumers with different education level, age, and gender were interviewed to get a statistic of their opinion about quality parameters preferred by them. This complex quality index/degree of satisfaction shows very high correlation with subjective judgment. A CQI can be evaluated for each kind of clothing material looking into their applications.

Europe is at crossroads in terms of growth and living standards. The nexus between circular economy, RESYNTEX and textile provides direction and opportunity for seamless prosperity. The current strategy consisting of a linear economy for resource utilization, a surprisingly wasteful model of value creation, is leading to decline in prosperity and concomitant global influence. It must develop a more resource savvy circular economy, with the biological and mineral nutrients of modern society continuously circulating. Rather than face a bleak and uncertain future dependent on resources from overseas, Europe needs to develop technologies towards self-sufficiency in energy and water and keep materials required for consumption flowing [1], This will insure reduction in virgin resources and treat waste as a valuable input rather than a burden for welfare of society and the environment. RESYNTEX, the European Union’s Horizon 2020 research and innovation funded program, will produce secondary raw materials from blends and pure components of unwearable textile waste and is expected to have a strong circular economy focus. The project will develop and demonstrate a strategic design for closed loop textile recycling throughout the value chain. [ABSTRACT FROM AUTHOR]

In this work, waste acrylic fiber web was impregnated with iron chloride solution and another web without salt impregnation was carbonized by heating under a layer of charcoal through physical activation in a high temperature furnace to produce activated carbon and iron impregnated activated carbon (FeAC). After stabilization at heating rate 50°C.hr-1 the carbonization process was performed at the heating rate of 300°C.hr-1. Both the webs were heated to 1200°C with no holding time for getting a higher surface area and porosity. Both the samples were characterized by using BET surface area, SEM, EDX and TGA for determining the surface area, microscopic structure and content of different elements. Iron impregnated activated carbon (FeAC) was later used as adsorbent for the removal of methylene blue from an aqueous solution. The dye removal percentage and adsorption capacity was checked at different experimental parameters like different dye concentrations, adsorbent dosage, stirring speed and different pH. [ABSTRACT FROM AUTHOR]

Spacer fabrics consist of three layers of fabrics which have ability to complement and maximize the essential thermal clothing comfort for various applications. Clothing comfort is also defined by the tactile sensations felt by a subject through the mechanical interactions between the body and the garment. In this research work, the thermal and compression properties of polyester/polypropylene and polyester/polypropylene/Lycra blended knitted spacer fabrics have been studied in relation to density, thickness, stitch density and type of spacer yarns (monofilament or multifilament). The objective of this study was to determine the influence of spacer fabric factors such as the constituent fibres, density, thickness, stitch density, type of spacer yarns and knit characteristics on the fabrics properties such as air permeability, relative water vapour permeability, thermal conductivity and work of compression. The experiment results show that the thermal conductivity and effusivity are closely related to the fabric characteristics such as the raw materials, type of spacer yarn, density, thickness and tightness of surface layer. Also, this study established that the compression resilience of the fabric made up of monofilament spacer yarn was better than that of the multifilament spacer yarn in spacer knitted fabrics. [ABSTRACT FROM AUTHOR]

Copyright of Vlakna a Textil is the property of Vyskumny Ustav Chemickych Vlaken and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Vlakna a Textil is the property of Vyskumny Ustav Chemickych Vlaken and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The limitation of aramid fiber is its surface property, which results in its very poor interfacial adhesion to most of commercial resins. In order to improve the surface property of the aramid fiber, ozone treatment was carried out in this work. The aramid fabrics were evaluated in terms of surface morphology, wicking effect, tensile property, and ball bursting test. The results showed that the surface morphology of aramid fabrics did not undergo an obvious change; the wicking effect increased slightly with an increase in ozone treatment time; the tenacity and elongation of aramid fibers and fabrics did not significant change after ozone treatment, but the tenacity and elongation of aramid yarns showed significant improvement after ozone treatment, and increased with the increase of ozone treatment time; the ball bursting load and penetration displacement had a slight increase as well after ozone treatment. Therefore, ozone treatment could be one method to improve the surface property of the aramid fiber.

The air flow and conjugate heat transfer through the fabric was investigated numerically. The objective of this paper is to study the thermal insulation of fabrics under heat convection or the heat loss of human body under different conditions (fabric structure and contact conditions between the human skin and the fabric). The numerical simulations were performed in laminar flow regime at constant skin temperature (310 K) and constant air flow temperature (273 K) at a speed of 5 m/s. Some important parameters such as heat flux through the fabrics, heat transfer coefficient, and Nusselt number were evaluated. The results showed that the heat loss from human body (the heat transfer coefficient) was smallest or the thermal insulation of fabric was highest when the fabric had no pores and no contact with the human skin, the heat loss from human body (the heat transfer coefficient) was highest when the fabric had pores and the air flow penetrated through the fabric.