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Textile fabrics as thermal insulators
Abstract and Figures
In recent times, a wide range of textile materials has been used as thermal insulators in many industrial applications. The thermal insulating properties of textile fabrics depend on their thermal conductivity, density, thickness and thermal emission characteristics. Experiments have been made with the aim of studying heat transfer by conduction through the different types of fabrics used as thermal insulators. 100% polyester and 100% polypropylene nonwoven fabrics are used in this work as case studies. The temperature variation through the selected fabrics is measured under different operating parameters such as densities and inlet temperature. The thermal response and behaviour for the selected fabrics used in this work as thermal insulators are illustrated. The relationship between the thermal conductivity and material density of the selected fabrics is studied. Polyester fabric has higher thermal resistance and specific heat resistance than polypropylene. Fabric thickness has a significant effect on the fabric temperature variations. The results of ?[Anova-two way measurements] are presented for 100% polyester and 100% polypropylene nonwoven fabrics. The temperature variation of the fabric increased with the testing time, and also decreased with the increase of fabric weight up to a certain limit beyond its optimum level. The results show that the selected nonwoven fabrics are suitable for usage as thermal insulators.
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... For the same thickness of non-woven thermal insulation product, a low density ensures a high thermal insulation potential, but for mechanical strength reasons this density must be increased. A balancing calculation of thermal and mechanical performance is necessary, also taking into account that around a density value of 60 kg/m 3 , the phenomenon of heat transfer through conduction becomes dominant and thermal insulation performance decreases significantly [48][49][50][51]. Research has demonstrated the possibility of obtaining thermal insulation mattresses produced using R-PET fibres characterised by a thermal conductivity coefficient around values of 0.035 W/mK [29]. ...
... For thermal insulation products produced using PET, the TIV coefficient ranges from 41.21% to 52.15% for thicknesses in the range 3.54-7.97 mm, increasing alongside increasing thickness [48][49][50][51]. ...
... Research results to date [55,56] have shown that recycled textiles have competitive thermal properties, thermal conductivity and thermal diffusivity, and can be used as an alternative to commercial thermal insulation materials (extruded polystyrene or mineral wool) in the construction sector. Danihelová et al. [55], in agreement with other reports [48] showed that recycled textile waste mattresses can be good thermal insulators, characterised by a thermal conductivity coefficient around 0.033 W/mK. Therefore, producing thermal insulation mattresses from a mixture of recycled PET fibres, recycled PES, fibres of plant origin and fibres of animal origin makes it possible to exploit the basic principle of composite materials: the accumulation of benefits. ...
The current context provides, worldwide, the need to identify solutions for the thermal efficiency of constructions, through sustainable and innovative methods and products. A viable solution is to produce thermal insulating products by carding-folding technology, using natural fibres and recycled polyethylene terephthalate (rPET) and polyester (rPES) waste, converted to fibres. This paper presents experimental results obtained after testing several thermal insulation composite products produced using a mix of sheep wool, cellulose, rPET and rPES fibres. The results of the research demonstrate the thermal insulation properties but, at the same time, identify the benefits of using such materials on the quality of the air in the interior space (the ability to adjust humidity and reduce the concentration of harmful substances). At the same time, the advantages of using sheep wool composite mattresses concerning their resistance to insect attack is demonstrated when compared with ordinary thermal insulation materials. Finally, sensitivity elements of these composites are observed in terms of sensitivity to mould, and to contact with water or soil, drawing future research directions in the development of this type of materials.
... Hadded et al. [23] studied recycled textiles in terms of thermo-physical characteristics (thermal conductivity and thermal diffusivity). Danihelová et al. [27] conducted a study on the performance of recycled technical textiles showing that, in line with other reports [28], mattresses made of recycled waste fibres of a vegetable or animal nature can be good thermal insulators, characterised by a thermal conductivity coefficient around 0.033 W/mK. The results of their research have shown that recycled textiles have competitive thermal properties and can be used as an alternative to the "classic" building insulation materials (extruded polystyrene or mineral wool). ...
... From the point of view of thermal conductivity, the recorded values indicate that an increase in temperature leads to an increase in thermal conductivity from 0.030 W/mK (at −5 • C) to 0.034 W/mK (at 35 • C)-for the CW sample and from 0.031 W/mK (at −5 • C) to 0.034 W/mK (at 35 • C)-for the DW sample. Zeinab et al. [28] analysed heat transfer through different types of non-woven fabrics. They studied the dependence of thermal conductivity on the thickness and density of polyester and polypropylene fibre insulation boards and concluded that, based on the measured value of thermal conductivity (approx. ...
Worldwide, the need for thermal insulation materials used to increase the energy performance of buildings and ensure indoor thermal comfort is constantly growing. There are several traditional, well-known and frequently used thermal insulation materials on the building materials market, but there is a growing trend towards innovative materials based on agro-industrial waste. This paper analyses the performance of 10 such innovative thermal insulation materials obtained by recycling cellulosic and/or animal waste, using standardised testing methods. More precisely, thermal insulation materials based on the following raw materials were analysed: cellulose acetate, cigarette filter manufacturing waste; cellulose acetate, cigarette filter manufacturing waste and cigarette paper waste; cellulose acetate, waste from cigarette filter manufacturing, waste cigarette paper and waste aluminised paper; cellulose from waste paper (two types made by two independent manufacturers); wood fibres; cellulose from cardboard waste; cellulose from waste cardboard, poor processing, inhomogeneous product; rice husk waste and composite based on sheep wool, recycled PET fibres and cellulosic fibres for the textile industry. The analysis followed the performance in terms of thermal insulating quality, evidenced by the thermal conductivity coefficient (used as a measurable indicator) determined for both dry and conditioned material at 50% RH, in several density variants, simulating the subsidence under its own weight or under various possible stresses arising in use. The results showed in most cases that an increase in material density has beneficial effects by reducing the coefficient of thermal conductivity, but exceptions were also reported. In conjunction with this parameter, the analysis of the 10 types of materials also looked at their moisture sorption/desorption capacity (using as a measurable indicator the amount of water stored by the material), concluding that, although they have a capacity to regulate the humidity of the indoor air, under low RH conditions the water loss is not complete, leaving a residual quantity of material that could favour the development of mould. Therefore, the impact on indoor air quality was also analysed by assessing the risk of mould growth (using as a measurable indicator the class and performance category of the material in terms of nutrient content conducive to the growth of microorganisms) under high humidity conditions but also the resistance to the action of two commonly encountered moulds, Aspergillus niger and Penicillium notatum. The results showed a relative resistance to the action of microbiological factors, indicating however the need for intensified biocidal treatment.
... 2 The use of coir and jute composites has many advantages compared to biological thermal insulators, including low product cost, good handling, and environmental protection. 3 The industrial materials are manufactured from natural fibers to offer thermal insulation applications. Different researchers give detailed manufacturing processes for composite materials & insulation ingredients and internal automotive applications. ...
... With different blending ratios of coir fibers and jute fibers. 4 Zeinab et al. 3 addressed heat passed through various kinds of composite materials that were used as thermal insulation. They studied that thermal physical properties depend on the thickness & density of the insulation of substances produced from coir and also the jute/plastic materials. ...
Thermal comfort property is closely related to the concept of thermal insulation and includes protection against heat. This research paper presents an experimental study on thermal insulation properties, for natural fiber composite materials: a natural fiber (Coir/Jute) with different blend proportions of raw materials mixed with rigid polyurethane foam as a binder. The natural fiber composite materials were characterized by both thermal resistance (Thermal Insulation Value TIV) and also in terms of heat transfer (thermal conductivity). Thermal insulation values were measured according to Lee’s disk method (ASTM C177). The influence of the structure of these materials on the thermal insulating properties was analyzed. The experimental results show the thermal resistance performances of natural fiber composites based on coir/jute fiber materials, thus promoting environmentally friendly solutions.
... The microporous structure of organic nonwoven mulches allows for light, air, and water to be transmitted to the soil, improving soil structure and enhancing soil nutrient availability, resulting in increased crop yield and quality, unlike plastic film [19]. Aside from raw materials and nonwoven fabric manufacturing technology, mass per unit area and thickness influence soil temperature and humidity fluctuations [20,21]. The critical role in air and water transmission through nonwoven mulch is fabric pore geometries. ...
The need for sustainable alternatives to conventional plastic mulches in agriculture has led to the development of various types of biodegradable mulches made from natural fibres and biopolymers to reduce environmental pollution and mitigate soil pollution caused by conventional plastic mulch usage. Degradation, impact on soil temperature and humidity, and weed suppression properties of needle-punched nonwoven mulches of different mass per unit area, made of jute, hemp, viscose, and PLA biopolymer, are investigated. Their biodegradation is determined by changes in the mulch properties (mass per unit area, thickness, air permeability, tensile properties, microscopic images, and FTIR analyses) during 300 days of exposure to the environmental conditions in the period from May 2022 to February 2023. The change in mass per unit area, thickness, air permeability, and tensile properties of nonwoven mulches did not show a tendency to degrade during exposure to environmental conditions. The microscopic and FTIR analysis showed the degradation of the fibres from the mulches during the exposure time to a certain extent. The environmental conditions influence the change in the dimensions of the mulches (shrinkage and expansion)—which impact periodically tested mass results per unit area—as well as their thickness and air permeability. The nonwoven mulches provide higher temperatures compared to bare soil, though not as high as those observed beneath traditional agricultural foil. When comparing the humidity in bare soil and soil covered by mulches during the plant growth period (June to October), it was found that soil humidity was higher beneath all mulches. The nonwoven mulches provide superior soil moisture retention compared to conventionally used agrofoil. Almost all nonwoven mulches effectively suppressed weed growth, except hemp mulches. The newly produced mulches have the potential to replace traditional agrofoil, offering improved conditions for plant growth, effective weed control, and faster degradation without causing harm to the environment.
... The uneven surface of natural fibers (cotton) usually has an irregular arrangement of capillaries in the yarn, which affects the flow of liquid (sweat). Most man-made fibers (bamboo) as well as synthetic fibers (polyester) have a generally smooth surface with a generally round cross-section, which contributes to faster fluid flow [10]. Due to the constant compression of the shoe on the foot with the sock on, moisture is transferred from the skin to the knit and vice versa, or from the knit to the inside of the shoe, which leads to wetting of the feet, i.e. more moisture in the microclimate area. ...
The influence of environmental conditions on the thermo-physiological comfort of men's socks was investigated using an objective assessment of comfort under dynamic conditions. Men's socks made in a 3:1 rib construction from three types of basic yarns (77%) were used: bamboo, cotton, and a cotton/polyester blend. The remaining composition of the socks is identical: filament polyamide yarn (22%) and wrapped rubber thread (1%) for the welt. The influence of climate factors artificially created in the climate chamber was analyzed by measuring three physiological parameters: skin temperature, relative humidity of the skin, and microclimate in the space between the sock and the shoe on both feet. The research results show that the raw material composition of the base yarn used in the manufacture of men's socks has a significant impact on thermo-physiological comfort when wearing socks. Under artificially created conditions in the climate chamber, an ambient temperature of 20 °C and relative humidity of 50% (autumn and spring conditions), socks with basic yarn made of a cotton/polyester blend are preferred, then with a base yarn made of cotton, and finally socks with a base yarn made of bamboo. The data from the study provide valuable information for the clothing industry in designing and defining the choice of base yarn to produce socks, depending on the conditions of use.
... The best fabric that gives the highest comfort properties was polyester 50%/ viscose 50% with loose structure (less tightness factor) 9. A positive correlation between fabric thickness and thermal insulation was found for textile fabrics 6,10 . ...
Thermal insulation, water vapour permeability, and air permeability were measured for three types of single jersey knitted fabrics, knitted at three different tightness factors on two single jersey knitting machines with two gauges. Fabrics were knitted from yarns with 30 Ne with the following fiber contents (100% cotton, 50% viscose / 50% cotton, 50% modal / 50% cotton). It was found that Modal/Cotton fabric gives higher air permeability, water vapour evaporation, and lower thermal resistance then comes 100% Cotton fabric then Viscose/Cotton fabric. Also it was found that fabric porosity is highly correlated with Thermal resistance, Air permeability, and Water vapour permeability for all fabrics under study. While fabric thickness affects significantly the properties under study for cotton, and modal/cotton fabrics. Also the loop length affects the comfort properties.
... Both samples have a very similar coefficient of thermal conductivity; therefore, they have similar thermal insulation properties. The results are analogous to those of other authors [27][28][29][30][31]. The non-woven fabrics' thermal insulation properties are comparable to those of foamed polymer insulators such as polystyrene, polyurethane, polyvinyl chloride, and others [32]. ...
In recent years, non-wovens have become the main segment of textile production because they can find applications in different areas. Thermal insulation properties, fire resistance, and flexibility make them cost-effective and efficient insulation panels for buildings. This paper aims to study the influence of the production method and surface treatment on the thermophysical characteristics and behavior under direct fire of two polyethylene terephthalate non-woven fabrics. The fibers have been bonded with polyacrylate adhesive or thermal and coated with silicone. Infrared spectroscopy, optical microscopy, and thermal analyses were applied to compare the non-wovens’ morphology, composition, and thermal properties. It founds that the non-woven polyester with acrylic additives and adhesive bonding has a higher thermal conductivity value and high flammability with complete combustion. In contrast, thermosetting siliconized polyester materials have limited flammability with limited droplet release. The silicone-based finish protects the polyester fibers leading to self-extinguishing and stopping the complete combustion of the sample.
... The structural parameters have an immediate impact on the comfort performance of the woven fabric Umair et al., 2016). Thermal comfort is a complex phenomenon, depending on a number of parameters such as yarn structure, fabric geometry, thickness, density, weave design and number of layers (Abdel-Rehim et al., 2006). The thermal resistance offered by the fabric decreases as the twist in yarn increases. ...
Purpose
This paper aims to investigate the influence of picking sequence, weave design and weft yarn material on the thermal conductivity of the woven fabrics.
Design/methodology/approach
This work includes the development of 36 woven samples with two weave designs (1/1 plain and 3/1 twill), three picking sequences (single, double and three pick insertion) and six different weft yarn materials (cotton, polyester having 48 filaments, polyester with 144 filaments, spun coolmax having Lycra in core and coolmax in sheath, filament coolmax and polypropylene). The thermal conductivity was measured using ALAMBETA tester.
Findings
The results showed that weft yarn material, weave design and picking sequence have a meaningful impact on the thermal conductivity of woven fabric. The value of thermal conductivity was lowest for the fabrics with three pick insertion and 3/1 twill weave in all weft yarn materials.
Research limitations/implications
Plain woven fabric with single pick insertion is feasible for summer wear to enhance the comfort of wearer. By changing the warp yarn grouping and material, improved thermal conductivity/resistance can also be achieved.
Originality/value
The authors have studied the combined effect of different weft yarn materials with different picking sequences and different weave designs on thermal conductivity of the woven fabrics.
Textiles are a basic need of people in all cast and sectors. Over the years, development in this field has become obligatory. Functional textiles have been a research hot spot with the rapid rise of nanotechnology in the last two decades. This review emphasizes the historical perspective and needs for the development and evolution of textiles, the present status of modern textiles, and the future. In the last few decades, the application of nanomaterials has upsurged in an unparallel way in textile fields. Due to the stimulating demand of the fashion industry for multifunctional nanotextiles, using nanomaterials in textiles has gained tremendous attention. Multifunctional textiles with nanomaterials are vibrant nowadays, offering UV blocking, wrinkle resistance, flame retardancy, antimicrobial, hydrophobicity/superhydrophobicity, sensors, self-cleaning, dust repellency, microwave absorption, tissue regeneration ability without compromising on comfortability and flexibility. Wearable textile sensing in textiles is also common to develop the sense-actuate system in the present era. This study also focuses on the market demand for functional textiles, challenges, and future market potential and perspectives.
This Clothing is placed not exclusively to protect the human body from harm, but also because it assists in achieving a state of comfort during strenuous activities or when the environment around the wearer is unfavorable. Clothing comfort is determined by the thermo-physiological comfort properties of the woven fabric, which include air permeability, thermal properties, moisture management, and handling properties. Different high-tech fibers, yarns, woven fabric construction and structure have radically altered people's fundamental need to be clothed as time has progressed. In this study, the thermo-physiological comfort properties of woven fabrics with differing construction and structure are investigated. Then comparisons are made keeping all parameters constant except one. It has been demonstrated that a higher thermal conductivity can be achieved by using coarser yarn in higher interlacing fabrics, such as plain fabric. On the other hand, the thermal conductivity of a fabric with low interlace density, such as 3/1 twill, is reduced when a coarser yarn is used. The thermal conductivity of fabric can be reduced to an acceptable level by using coarser yarn and less interlacing. Fabrics with heavier constructions are less air permeable than those with lighter constructions.
The effectiveness of a fabric as a thermal insulator depends upon its ability to hold as large an amount of still air as possible and then to retain this during use. It its resistance to compression and its ability to recover after compression are high, the still air is retained, and the fabric continues to provide good thermal insulation. Studies on heat-transfer characteristics indicate that thickness is the most important factor in determining the thermal resistance of textile materials. Good thermal insulation is obtained with thick fabrics irrespective of the fibre material. Smooth continuous-filament yarns are not suitable for making bulky fabrics, so it would appear that the natural staple fibres, particularly wool, are to be preferred. But, if synthetic-fibre yarns are used in the crimped-staple form instead of as continuous-filament yarns, fabrics of good thermal insulation will be obtained. An ideal clothing fabric, in terms of thermal comfort, should have the following attributes: a) high thermal resistance for protection from cold; b) low water-vapour resistance for efficient heat transfer under a mild thermal-stress condition; and c) rapid liquid-transport characteristics for transferring heat efficiently and eliminating unpleasant tactile sensations due to water under high-thermal-stress conditions. To develop a material with the insulating properties of still air, it should possess the following attributes: be a porous solid; have a low density (2.0 lb ft "SUP -3" (3.2kg m "SUP -3" ) maximum); have low surface emissivity; Have its cell-wall thickness small in comparison with the cell diameter; be permeable to air; be permeable to water vapour. In designing fabrics to provide thermal insulation, we must balance the effect of fibre and construction on the different modes of heat transfer and take into account the other properties required, such as wind and rain resistance, with the aim of achieving a compromise to obtain the optimum performance in a given situation.
A mathematical model is developed for heat and mass transfer analysis of fabric in the tenter frame. Using the model, the calculated transient fabric temperatures in the tenter frame agree well with the experimental values measured by Beard. Variations in temperature and moisture content distribution are solved using the finite-difference method. The effects of operation parameters, such as temperature and humidity in the tenter, initial moisture content of the fabric, and heat and mass transfer coefficients, are examined using the model.
Recently a wide range of materials is available in the form of fibres or fabrics for use in electrochemical reactors and other applications. The problem of heat transfer through fabric materials is theoretically solved—a model representing the plain weave fabrics is given, which facilitates the application of the heat transfer equations. As a result the effective thermal conductivity of fibrous materials in a fabric form, yarn form, or even in fibre form could be predicted.
Two kinds of recycled fiber assemblies made from knitted sweaters fabrics are exam ined by measuring compression, thermal, and air resistance properties, and they are compared with a pure wool assembly and a wool-blend assembly. For recycled fiber assemblies, the initial volume for a constant weight and stiffness to compression process are smaller than those of other samples at the same apparent fiber density. The effective thermal conductivities of recycled fiber assemblies are smaller than those of wool fiber assemblies. Recycled fiber assemblies show larger specific air resistance than the other samples when the volume fraction is the same. A recycled fiber mass has a unique structure, that is, some yams extracted from fabrics remain in the fiber mass. These yams do not show any decrease in compression, thermal, and air permeability properties compared with commercial fiber assemblies. These crimped yams in the fiber mass contribute to softness at the high fiber density apparent in compression.
This paper deals with thermal insulation and thermal contact properties of woven fabric assemblies used to produce men's jackets. An important part of the paper is the description of the new computer-controlled instrument, the Alambeta, to measure insulation and thermal contact properties of fabrics. The heat flow passing between the textile sample and measuring head during thermal contact is measured directly by a special thin sensor, whose thermal inertia is similar to that of human skin. Thus, the instrument's warm-cool feeling sensitivity aproximates human skin. Spotbonding the outer fabric interlining and lining together reduces the total thermal resistance of the assembly and simultaneously increases (makes cooler) thermal absorptivity, a new parameter used to describe the warm-cool feeling of fabric. The meaning of this pa rameter, which mainly reflects the surface properties of the fabrics and whose level does not depend on experimental conditions, is explained in detail. The effect of temperature drop on the thermal properties of the fabric assemblies is also investigated. The increased resulting thermal conductivity with the average temperature of the assembly is a consequence of the increased portion of the heat transferred through the system by radiation.
From a survey of the literature covering the years 1930—50 the available physical data on the thermal properties of textiles have been collected. The thermal properties were divided into three sections : (a) Factors contributing to thermal insulation. Thermal insulation is defined as the effectiveness of a fabric in niaintaining the normal temperature of the human body under equilibrium conditions. (b) Factors contributing to ̒ cold feel ̓. ̒ Cold feel ̓ is that property which is assessed by the initial reaction of a person on touching a fabric. (c) Factors contributing to ̒ chillproofness ̓. ̒Chillproofness̓ is defined as the ability of a fabric to reduce the effect on the hurnan body of sudden changes in atmospheric temperature and humidity. Thermal insulation of fabrics depends largely on the thickness of the fabric and is independent of the fibre material. The ̒cold feel̓ depends mainly on the area of contact between fabric and skin ; thus fabrics made from continuous filament yarns are ̒colder̓ than those made from highly crimped staple, independent of the type of fibre. The ̒chillproofness̓ depends upon the water-absorption and the heat of absorption of the fibre material.
A model of heat and water transfer through layered fabrics, such as wearing clothing, is developed in this paper. All particular properties of recently developed fabrics are considered: hydrophobic or hydrophilic treatment, membranes glued onto a layer. and surface modification of the textile (abrading). Physical phenomena taken into account are sorption or desorption; free water condensation or evaporation: liquid. vapor, and ad sorbed water diffusion; and heat conduction and contact resistances between layers. The model is dynamic for one-dimensional transfers. Considering this particular porous medium, the energy and mass balance lead to a system of two differential equations (moisture, temperature). The validity of the model is examined in light of basic experi ments existing in the literature. The hygroscopic character of a fabric can be expressed by a diffusion coefficient, which is a function of the water content. Two possible formulations of this property are given.
A mathematical model has been developed to describe the dynamic heat and moisture transport behavior of clothing and its interaction with the human thermoregulation system under transient wear conditions. A modification of Gagge's two-node model is used to simulate the human physiological regulatory responses. In clothing, heat and moisture transport is coupled with the sorption or desorption of water vapor in the fibers and the associated energy changes. If the physical activity and ambient conditions are specified, the model can predict the thermoregulatory responses of the body, to gether with the temperature and moisture profiles of the clothing. Experimental mea surements with garments made from fibers with different levels of hygroscopicity are compared with predictions by the model. There is good agreement between prediction and experiment for skin and fabric temperatures and the relative humidity of the cloth ing microclimate.
In this paper we describe a study of the thermal-expansion behaviour of hot-compacted woven polypropylene and polyethylene composites. The thermal expansion of the compacted sheets is shown to relate to both the molecular structure which is produced after the hot-compaction procedure has been completed and the architecture of the woven material, which includes the effects of thermal and elastic anisotropy. The annealing effect of the hot-compaction process on the structure of hot-compacted polypropylene tapes, was investigated by measurements of shrinkage force, elastic modulus and thermal expansion measurements. The hot-compaction process is seen to have a profound effect on the structure of the original polypropylene tapes, owing to the combined effects of shrinkage of the oriented amorphous phase and melting and recrystallisation of the crystalline fraction. The influence of the woven architecture of the composites has been investigated through the development of a simple model, which shows that the measured composite values can be understood in terms of the anisotropic thermal expansion of the individual fibres or tapes of which the compacted composites are composed, together with their anisotropic thermal and elastic properties: account is also taken of the woven architecture which comprises the compacted woven materials. The effect of the mechanical and thermal anisotropy was, as expected, found to be most pronounced in the hot-compacted polyethylene composites.