Sage Journals: Discover world-class research

Abstract

This paper reports a study on potential applicability of nonwoven samples made from textiles waste in building industries. Four nonwoven fabrics based on acrylic and wool waste were made using the needle punching technique, and tested in terms of thermo-physical properties. Results show that all developed nonwovens have an excellent insulation performance, the thermal conductivity is in the range of 0.03476–0.04877 W/(m·K); these values are comparable with that of conventional insulation materials. The lowest value of the thermal conductivity is observed for the nonwoven made from washed wool Wr (0.03476 W/m.K). In order to evaluate the thermal performance of manufactured nonwoven, a reduced-scale thermally controlled cavity was used; each wall of the cavity is outfitted with one nonwoven. The comparison is based on the outside surface temperature walls. The fixed inside surface temperature was 36 ℃; however, the outside surface temperature was less than 19 ℃. This result is in accordance with the obtained thermal conductivity values and confirms that materials based on textile waste have competitive thermal properties and could be used in building insulation materials.

Keywords

Textile waste building insulation energy efficiency thermal conductivity needle-punching technique

Introduction

The energy and environmental context of the beginning of the 21st century is marked by the question of sustainability at all levels: mineral and energy resources, living environment, health and biodiversity [1]. In terms of energy, the imbalance between energy and consumption of energy based on limited mineral resources favors tensions of all kinds (economic, geographical, social, etc.) [2]. From the environmental point of view, human activities exploit the resources provided by the terrestrial biosphere and emit residues from their productions in the form of waste in the biosphere [3]. The large increase in human activities leads, in the longer or shorter term, to significant impacts at all scales (local, regional, global). At the global level, the building sector is one of the most dynamic sectors, it accounts for more than 32% of final energy consumption and contributes about one third of CO₂ [4]. The building sector is also responsible for approximately two-thirds of halocarbon and approximately 25–33% of black carbon emissions [5]. Most of these emissions come from the combustion of fossil fuels to provide heating, cooling and lighting, and to power appliances and electrical equipment [6]. The energy consumption in buildings is growing and is expected to grow dynamically due to many reasons. Reducing energy consumption in buildings represents a major economic and environmental challenge and becomes a priority in energetic policies [7]. Many cost-effective options are already available in the buildings sector that can significantly reduce both energy consumption and emissions [8]. It is therefore urgent to adopt a new vision based on an efficient use of energy as a factor of competitiveness and sustainable development. Therefore, the increase in energy efficiency and the integration of renewable energy through the reduction of greenhouse gases, represent the main challenges to be faced, especially since the building has great economic potential to contribute to this objective [9]. Thermal insulation is often the first step to reduce energy requirements in a building, it can both reduces the heating and/or air conditioning energy consumption and increases thermal comfort, it is also a major contributor and obvious practical towards achieving energy efficiency. According to the literature, a good insulation could save about 65% of energy consumption [10]. There are a wide variety of insulations on the market, which can be categorized according to their forms, use and their compositions. Insulation materials can be made in different forms (loose-fill form, blanket batt or roll form, rigid form, foamed in place, or reflective form) [11]. The choice of insulation materials cannot be based only on practical and economic considerations, but must also integrate ecological considerations (energy and environmental issues).

Manufacturing of textile products causes a large quantity of wastes, commonly disposed into landfill or used for energy recovering. Considering the European Union, around 5.8m tons of textiles are discarded by the consumers per year. Only 1.5m tonnes (25%) of these textiles are recycled by charities and industrial enterprises. The remaining 4.3m tonnes go to landfill or to municipal waste incinerators [10 –12]. The reuse and recycling of discarded textiles has several potential environmental benefits. Recent studies have been reported on the possible integration of textile waste in building insulation, these studies have shown that textile waste has physical properties comparable to conventional insulation [13].

Patnaik et al. [14] studied a new insulating material made from waste wool and recycled polyester fibers (RPET) for building industry applications. Samples were tested in terms of thermal insulation, acoustic absorption, moisture absorption, fire retardancy, and biodegradation behavior. RPET/waste wool mats showed the best thermal insulation, acoustic absorption, moisture absorption and good fire properties. In another study, the potential applicability of acrylic woven fabric waste (WFW) and a waste of this residue, named woven fabric sub waste (WFS), as thermal insulation building material was studied. Experimental work was conducted using an external double wall, with the air-box filled with these two types of waste. The obtained results show that the application of the WFW and WFS in the external double wall increases its thermal behavior in 56% and 30%, respectively [15].

El wazna et al. [16] evaluated the potential of textile waste application in building insulation in the form of a nonwoven fabric, and also investigated the effect of porosity and density on thermal conductivity and air permeability of needle-punched non-woven fabrics. They found that there is no simple correlation between the properties of nonwoven and porosity because of the strong dependence of flow rate on the width, shape, and tortuosity of the conducting channels.

Hadded et al. [10] determined the coefficients of thermal conductivity of two textile waste samples (waste linter and tablecloth). The results show that the recycled textile materials have competitive thermal properties and could be used in the building insulations materials.

In order to test the thermal performance of the building walls, Gounni and El Alami [17] used a cavity at reduced scale, thermally controlled. Instead of cavities at real scale, the cavities at reduced scale have the advantage to use removable and exchangeable walls to discuss several configurations with or without insulation and with different thicknesses.

The aim of the present study was to produce a new insulation material in a form of nonwoven with a low heat transfer coefficient and a low thickness using textile waste. Four nonwoven waste based on acrylic and wool, termed here as As, Ak, Wc and Wr, were prepared using needle punched technique and tested in terms of physical-microstructural properties. The second part of this article evaluates the thermal performance of manufactured nonwoven in a small-scale building termed here as reduced-scale cavity using lightweight walls with or without textile insulation.

Materials and methods

Textiles waste

In this study, the textile waste cuttings are taken from a Moroccan textile. After the waste collection stage, they were sent to a shredding company. The textile waste consists of acrylic and wool.

The final form of waste is shown in Figure 1.

Figure 1.

Shredded textile waste.

Manufacturing insulation nonwoven

The nonwoven webs were prepared according to the needling technique [16], it is defined as a method of consolidating the mats by the repeated insertion of barbed needles into the fibrous web. This process consolidates the structure of the fibrous web without any binder by interlocking fibers. Short staple fibers 40–50 mm of length were initially opened and cleaned using DILO CFL 7 10065/2012 machine (Figure 2(a)) with a flow rate of 5 kg/min. Then, the fibers are introduced into the card stage (Figure 2(b)), in which they are arranged in the form of a fibrous web in various orientations using DILO CAL7 10065/2012 with an output rate of 10 m/ min. At this stage, the thickness of web is controlled by means of a cross lapper type DILO F/6 10067/2012 (Figure 2(c)) with a folding factor of 10 equivalent to 10 fold per meter. Finally, fibrous web are feeded into the needle loom (Figure 2(d)) where they are perforated by a set of barbed needles to obtain a consolidated form using a DILO DI-LOOM OD-II 10069/2012 machine. The punch density used was 90 punch/cm² and strokes was set at 300/min. The final form of the insulation nonwovens are shown in Figure 3. Two of this insulation nonwovens are 100% acrylic (Figure 3(a) and (b)) and the two other insulations are 100% wool (Figure 3(c) and (d)). The difference between those non-woven is their source. The thermo-physical characterization of the used textile waste materials is established and then their thermal performance is tested in a cavity at reduced scale. Notice that all manufacturing parameters were kept the same for all samples. All manufactured nonwoven were conditioned for 24 h prior to testing in a standard testing atmosphere maintained at 65 ± 4% humidity and 20 ± 2 ℃ temperature.

Figure 2.

Illustration of DILO machine used for the manufacture of insulation nonwoven.

Figure 3.

Flexible insulating nonwovens; a: 100% acrylic knitting waste, b: 100% acrylic spinning waste, c: 100% washed wool, d: 100% carpet waste wool.

Thickness, mass per unit area, density and air permeability

The thickness (t) of samples were measured according to standard ISO 9073-2 [18] using Thickness Lab 1880. The mass per unit area of the sample is measured according to standard EN 12127 [19] using an electronic balance, five samples of 100 cm² were taken with using a cutting dispositive. Five random readings were taken for measuring thickness and area weight. Bulk density ρ [kg/m³] is defined as the ratio of the mass per unit area [kg/m²] and thickness [m]. This parameter is correlated with the thermal capacity of the material.

The air permeability of a building characterizes the sensitivity of the building to parasitic aeraulic flows caused by leaks in its envelope, or more simply the amount of air entering or leaving through it. It is quantified by the value of the leakage flow passing through the envelope under a given pressure differential. In this work the air permeability was determined by using AIR-TRONIC according to the ASTM D737-04 [20]. The test was conducted at pressure difference of 200 Pa for a surface area of 10 cm².

The measurement result of air permeability is based on equation (1)

k = \frac{Q}{S . t}

(1) where k is rate of flow L/(m². s), Q is volume of flow of fluid through the sample [L], t is time [s] and S is the cross-sectional area [m²].

Thermal conductivity and thermal resistance

The thermal conductivity λ of material is defined as the amount of heat crossing a unit area of the material per unit time per unit temperature gradient [16 –21].

The guarded hot plate apparatus lambda-Meter EP500e was used for measuring the thermal conductivity as per the EN 12667 standard [22]. It measures the sample thickness e [m] of the inserted sample, the temperature difference ΔT [K] over the sample and the heat flux Q [W/m²] which is equivalent to the electrical power P = U.I of the measuring heating. The thermal conductivity λ [W/(m.K)] is determined based on the defined measurement area S [m²] and the one-dimensional thermal conduction as follows

λ = \frac{Q . e}{S . Δ T} = \frac{U . I . e}{S . Δ T}

(2)

Sample size used for measurement was 200 mm×200 mm. In this study, the measuring temperature was 10, 25 and 40 ℃. Moreover, the temperature difference between the hot plate and the cold plate is set at 15 ℃ in all measurements.

The thermal resistance is expressed by the following relationship

R_{th} = \frac{e}{λ}

(3) where e [m] is the thickness of the sample, λ is the thermal conductivity [W/(m.K)].

Thermal performance of the nonwovens using test cell

Test cell description and measurement devices

The thermal performance of walls outfitted with the studied insulating mats is measured using a cavity at reduced scale termed here as test cell (Figure 4).

Figure 4.

Thermally controlled cavity at reduced scale.

It is a cubic box which held 0.4 m × 0.4 m × 0.4 m walls. Each wall contains one type of insulation. The insulating mats are installed between two wood layers as shown in Figure 5. Each layer of the wood and insulating mats has a thickness of 1 cm. The thermal characteristics of the materials used are presented in Table 1.

Figure 5.

Schematic of the wall showing the location of the insulating mats.

Table 1.

Thermal characteristics of the wall materials [15].

Test cell layers	Thermal resistance, m².K/W
Wood	0.076
Air gap	0.14
Superficial exterior (R_se)	0.04
Superficial interior (R_si)	0.13

The heating of the test cell is provided by an incandescent bulb mounted in a black window protection placed at the center of the test cell. Later, this cell is housed in a conditioned large scale local in order to control the exterior air temperature and boundary conditions. Under this arrangement, the interior of the test cell simulate the outdoor environment of a real building, while the exterior of the test cell simulate the indoor environment of a real building. The same experimental set up was used in a previous work and the obtained results are successfully validated [17].

The thermal transmission coefficient of insulating walls

Thermal transmittance also known as U-value, is the rate of heat transfer through a structure (which can be a single material or a composite), divided by the difference in temperature across that structure [15]. A low U value, reflects a better insulated structure. The U-value can also be quantified by applying the following expression, which is specific to the test cell

\begin{matrix} U = \frac{1}{R_{si} + \int_{j = 1}^{m} \frac{e_{j}}{λ_{j}} + R_{se}} = \frac{1}{R_{si} + \frac{2 e_{w}}{λ_{w}} + \frac{e_{N}}{λ_{N}} + R_{se}} = \frac{1}{R_{si} + e (\frac{2}{λ_{w}} + \frac{1}{λ_{N}}) + R_{se}} \end{matrix}

(4) with e_W = e_N = e

In which U is the thermal transmission coefficient; e is the thickness of the layer j; λ is the thermal conductivity of the material of the layer j; m is the number of layers of the walls; e_W is thickness of wood layer; e_N thickness of nonwoven insulation; λ _W is the thermal conductivity of wood layer; λ _N is the thermal conductivity of nonwoven insulation; R_si is superficial interior thermal resistance is equal to the inverse of the heat exchange coefficient of inner surface hi; R_se is superficial exterior thermal resistance is equal to the inverse of the heat exchange coefficient of external surface he.

Results and discussion

Analysis of the thickness, mass per unit area, density and air permeability of insulation nonwoven

Sample compositions and their physical properties are shown in Table 2. It is concluded that the density of different nonwoven fabric is very low compared to the conventional insulation materials (Table 4) due to their highest porosity which is considered as one of the main factors.

Table 2.

Physical properties of the manufactured nonwoven.

Parameter	Needle-punched non-woven
Parameter	100% Washed wool (Wr)	100% Carpet waste wool (Wc)	100% Acrylic spinning waste (As)	100% Acrylic knitting waste (Ak)
Thickness (mm)	13 ± 0.3	12 ± 0.3	14 ± 0.3	12 ± 0.3
Area weight (g/m²)	106 ± 5	127 ± 3	204 ± 2	136 ± 2
Density (kg/m³)	8.153	10.583	14.571	11.333
Air permeability (L/m².s)	1750 ± 83	1100 ± 233	267 ± 50	1216 ± 83

The control of air permeability is a major issue in the context of the objectives of improving the energy performance of buildings by limiting parasitic airflows and wasted energy. Indeed, for insulation to perform properly, air must not be allowed to move through it. According to the literature, the value of air permeability of the nonwoven, shown in Table 2, is satisfactory [21]. According to the experimental results, it is observed that the air permeability of the nonwoven fabrics decreases with increasing density. This finding is confirmed by previous studies [16 –21].

Analysis of the thermal conductivity and thermal resistance of insulation nonwoven

The thermal conductivity analysis was carried out at three temperatures 10 ℃, 25 ℃, and 40 ℃ for a duration of 280 min. This period time is sufficient to obtain a steady state and this is reflected by a stabilization during the measurement as shown in Figure 6. The thermal conductivities of samples are shown in Table 3. All developed nonwovens show an excellent insulation performance (λ < 60 mW/K.m). Indeed, the lowest value of λ are observed for the nonwoven made from washed wool (34.76 mW/m.K). The thermal resistances of the samples were obtained from the measured values of the thermal conductivity λ and thickness, the highest value is observed for the washed wool (Rth = 0.373 m²· K/W).

Figure 6.

Thermal conductivity versus time for 10, 25 and 40℃.

Table 3.

Thermal properties of the manufactured nonwoven.

Parameter		Needle-punched non-woven
Parameter		100% Washed wool	100% Carpet waste wool	100% Acrylic (spinning waste)	100% Acrylic (knitting waste)
Thermal conductivity (mW/m·K)	10℃	34.76	38.27	42.9	43.1
	25℃	37.45	40.76	45.41	45.81
	40℃	40.85	44.11	48.58	48.77
Thermal resistance (m² · K/W)	10℃	0.373	0.313	0.326	0.278
	25℃	0.347	0.294	0.308	0.261
	40℃	0.318	0.27	0.288	0.246

Table 4.

Thermal properties of the manufactured nonwoven and other insulators [11].

Materials		Density (kg/m³)	Thermal conductivity (W/m.K) normative value	“R” value per 1 cm
As		11.333	0.0431	0.232
Ak		14.571	0.0429	0.233
Wc		10.583	0.03827	0.26
Wr		8.153	0.03476	0.287
Conventional insulations	Rockwool (natural rocks)	40–200	0.037–0.040	0.27–0.25
	Perlite (natural glassy volcanic rock)	32–176	0.04–0.06	0.25–0.166
	Vermiculite (natural mineral)	64–130	0.063–0.068	0.158–0.147
	Glass wool	24–112	0.032–0.035	0.312–0.285
	Expanded Polystyrene	16–35	0.037–0.038	0.27–0.263
	Extruded Polystyrene	26–45	0.030–0.0320	0.33–0.312
	Polyurethane foam	30–80	0.02–0.027	0.5–0.37

El wazna et al. [16] assimilated nonwovens into a two-phase system consisting of a skeleton of dense fibers and air high porosity. This system is characterized by particular direction of fiber and also very high porosity. The thermal conductivity is related to the presence of pores, trapped air in pores gives a better thermal conductivity coefficient. They also found that the more the material is less dense (porous), the lower its conductivity, which explains the low conductivity found for the Wr sample.

Some of the most common materials used for insulation and manufactured nonwoven are compared in Table 4. The thermal conductivity in the range of 0.03476–0.04877 W/(m·K) and it is comparable with the conventional insulation materials.

The results show that the thermal conductivities of samples are closely to the rock wool, glass wool, extruded polystyrene and much better than the perlite and vermiculite, but for polyurethane or extruded polystyrene, the value of the thermal conductivity is slightly higher.

The conventional insulation mentioned in Table 4, despite presenting a good thermal properties, has a number of disadvantages, such as the irritating nature of glass and rock wool, the emitted gas from polystyrene under the action of heat, the recycling of polyurethane and the most important problem is their dependence on petroleum raw materials [11]. On the contrary, the manufactured insulators come from recyclable material and their production does not include in environmental pollution. They are developed according to processes requiring low energy expenditure and they are cheaper.

Using the “R” system of grading which is defined as the ratio of thickness [m] and the coefficient of thermal conductivity [W/(m.K)]), it is possible to compare the thickness of the insulators with equivalent “R values”. As shown in Table 4, the thermal resistance of the samples is identical to rock wool, glass wool, extruded polystyrene, and much better than perlite and vermiculite for a thickness of 1 cm, nothing that the thickness of the commercial insulators is much greater than 1 cm. Many factors that could be considered when determining the appropriate insulation solution such as: hygrometric regulation, the durability of the insulation, the flammability, the price and environmental performance. It is also important to consider the thickness of the insulation which directly affects other factors such as insulation costs (materials and installation).

Based on Table 3, the relationships between the thermal conductivity coefficient λ and temperature T were compiled. Figure 7 presents the thermal conductivity of the manufactured nonwoven versus temperature. A linear increase in thermal conductivity coefficients with changes in temperature is observed and the following functional dependencies are determined:

λ = 0,2033T + 32,607 with R² = 0.9954 [for 100% washed wool sample]

λ = 0,1947T + 36,18 with R² = 0.9928 [for 100% carpet waste wool sample]

λ = 0,1893T + 40,897 with R² = 0.9955 [for 100% acrylic (spinning waste) sample]

λ = 0,1890T + 41,168 with R² = 0.9994 [for 100% acrylic (knitting waste) sample]

Figure 7.

Dependence of the thermal conductivity coefficient on temperatures for each test sample.

Those equations permit to calculate the thermal conductivities of the nonwoven fabrics in the range of [10, 40 ℃].

Analysis of the thermal performance using test cell

Operative conditions

The tests were carried out during a two-cycle period. For each cycle, the heat source inside the test cell is switched “on” for 5 h and its set point is 36 ℃. Then the source was switched off for 5 h. To create a temperature difference between the outdoor and indoor environments of the test cell, the outdoor air temperature is kept constant at a low temperature of 15 ℃ (Figure 8) using an air conditioner. For each wall, two k-type thermocouples (2/10 mm), with an error of 0.1 ℃, are installed on the internal and external surface.

Figure 8.

The resulting indoor and outdoor air temperatures.

Calibration test

To verify that the test cell walls have a similar thermal performance before the incorporation of the insulating mats, a calibration test was performed. Exterior and interior surface temperatures of the four walls, without the insulating mats are measured and compared to verify their thermal similarities. As shown in Figure 9, the inside and outside surface temperature of the vertical walls are almost identical with a small deviation due to the thermocouples error as presented in the section Analysis of the thermal performance using test cell (Operative conditions). This conclusion confirms that the vertical walls have identical thermal performance.

Figure 9.

Exterior and interior surface temperature of the vertical walls with only wood layers during the calibration test.

Thermal performance of the insulating walls

Figure 10 shows the outside surface temperature comparisons for the walls outfitted with the insulating mats. First of all, it is concluded that the four textile wastes showed a great thermal insulation ability. This conclusion is based on the comparison between the fixed inside temperature (i.e. 36 ℃) showed in Figure 6 and the outside surface temperature of the four walls which not exceed 20.295 ℃ for the wall outfitted with Ak. For example, the wall outfitted with the Wr allows a reduction of 16.952 ℃ at its peak temperature.

Figure 10.

Outside surface temperature.

During the heating period (700–1000 min), the thermal responses of the walls outfitted with Wr and Wc are nearly identical with a deviation of 0.2 ℃. The same observation for walls outfitted with As and Ak are nearly identical with a deviation of 0.5 ℃. Moreover, it is shown that the Wool (i.e. Wr and Wc) has a better thermal insulation capacity than the Acrylic (i.e. As and Ak). The peak outside surface temperature measurements are seen in Table 5. The thermal behaviors of the walls with nonwoven fabrics agree with the values of the thermal properties related to the nonwoven fabrics. In fact, thermal conductivity characterizes the behavior of materials during heat transfer by conduction. The lower the thermal conductivity, the more the product insulates. In the first minutes of the heating off period, the nonwoven fabrics continue to play their role as thermal insulator until 1100 min in which the curves become identical.

Table 5.

The peak outside surface temperature related to the second cycle.

Walls	100% Washed wool (Wr)	100% Carpet waste wool (Wc)	100% Acrylic spinning waste (As)	100% Acrylic knitting waste (Ak)	Empty air gap
Peak outside surface temperature (℃)	19,048	19,230	19,796	20,295	–
U-value (W/m².K)	1.635	1.709	1.795	1.8	2.15

The obtained data through the experimental test were introduced in Expression (4) in order to obtain U-value for the walls systems. The U-value measure how effective elements of a buildings fabric are as insulators and also reflects the rate of heat loss. The lower the U-value, the more slowly heat is able to transmit through it, and so the better it performs as an insulator. The U-values of walls outfitted with the insulating mats are shown in Table 5. It is concluded that the four insulators have a good transmittance value (U-value) for 1 cm of thickness, the lowest value is observed for the Wr sample due to its low thermal conductivity. Comparing the values of U outfitted walls (U_Wr, U_Wc, U_As,U_Ak) and U empty air-gap it is possible to conclude that the application of the textile waste non-woven fabric improves the thermal behavior of the walls, in 24%,20.5%,16.5% and 16.2% respectively. This result leads to the conclusion that the Wr has better insulation characteristics than the others (Wc, As, and Ak).

Conclusion

Nonwovens materials are unique structures consisting of a skeleton of dense fibers and pores; due to their unique fiber orientation and porous structure, nonwovens are ideal materials for insulation applications. This article presents the development of four nonwoven fabrics using the needle punching technique, and tested in terms of physical and thermal properties. All developed nonwovens show an excellent insulation performance, the thermal conductivity in the range of 0.03476–0.04877 W/(m·K) and it is comparable with that of conventional insulation materials. The determination of the thermal conductivity is made in three different temperatures (i.e. 10 ℃, 25 ℃, 40 ℃). A linear relationship between the thermal conductivity coefficient and temperature is observed. This result is of great importance in order to determine thermal conductivity of the developed nonwoven, in the range of [10 ℃, 40 ℃]. On the other hand, the lowest value of λ is observed for the nonwoven made from washed wool (0.03476 W/m.K). The thermal performance of manufactured nonwoven is tested using a reduced scale cavity thermally controlled. Each wall of the cavity is outfitted with one nonwoven, and then, a comparison is made based on the outside surface temperature walls. A great reduction is observed, in terms of surface temperature. This result is in accordance with the obtained thermal conductivity values. Moreover, the filling of walls with W_r, W_c, A_s and A_k improves the thermal behavior of the walls, 24%, 20,5%, 16,5% and 16,2% respectively. Based on the experimentally obtained measurement results, it can be stated that manufactured nonwovens are good candidates to be used as low cost and environmental friendly insulation materials not only in buildings but also in automotive, furniture and clothing industries.

Footnotes

Declaration of conflicting interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) received no financial support for the research, authorship, and/or publication of this article.

References

Palmer

. Environmental education in the 21st century: theory, practice, progress and promise, London: Routledge, 2000.

Rüttinger L and Feil M. Sustainable prevention of resource conflicts: new risks from raw materials for the future? Case Study and Scenarios for China and Rare Earths, 2010.

Bergstrom

Randall

. Resource economics: an economic approach to natural resource and environmental policy, Edward Elgar Publishing, 2016.

Pérez-Lombard

Ortiz

Pout

. A review on buildings energy consumption information. Energy Build 2008; 40: 394–398.

Ürge-Vorsatz

Cabeza

Serrano

et al.

Heating and cooling energy trends and drivers in buildings. Renew Sustain Energy Rev 2015; 41: 85–98.

Wright

. What is the relationship between built form and energy use in dwellings?. Energy Policy 2008; 36: 4544–4547.

Iwaro

Mwasha

. A review of building energy regulation and policy for energy conservation in developing countries. Energy Policy 2010; 38: 7744–7755.

Torcellini

Pless

Deru

et al.

Zero energy buildings: a critical look at the definition, US: National Renewable Energy Laboratory and Department of Energy, 2006.

Dincer

. Renewable energy and sustainable development: A crucial review. Renew Sustain Energy Rev 2000; 4: 157–175.

10.

Hadded

Benltoufa

Fayala

et al.

Thermo physical characterisation of recycled textile materials used for building insulating. J Build Eng 2016; 5: 34–40.

11.

Al-Homoud

. Performance characteristics and practical applications of common building thermal insulation materials. Build Environ 2005; 40: 353–366.

12.

Asdrubali F, et al. A review of unconventional sustainable building insulation materials. Sustain Mater Technol 2015; 4: 1–17.

13.

Zach

Korjenic

Petránek

et al.

Performance evaluation and research of alternative thermal insulations based on sheep wool. Energy Build 2012; 49: 246–253.

14.

Patnaik

Mvubu

Muniyasamy

et al.

Thermal and sound insulation materials from waste wool and recycled polyester fibers and their biodegradation studies. Energy Build 2015; 92: 161–169.

15.

Briga-Sa

Nascimento

Teixeira

et al.

Textile waste as an alternative thermal insulation building material solution. Construct Build Mater 2013; 38: 155–160.

16.

El Wazna

El Fatihi

El Bouari

et al.

Thermo physical characterization of sustainable insulation materials made from textile waste. J Build Eng 2017; 12: 196–201.

17.

Gounni

El Alami

. Experimental study of heat transfer in a reduced scale cavity incorporating PCM into its vertical walls. J Thermal Sci Eng Appl 2018; 10(1): 011010.

18.

ISO 9073-2:1995. Test methods for nonwovens. Part 2: determination of thickness.

19.

EN 12127:1998. Determination of mass per unit area using small samples, British Standard.

20.

ASTM D737-04:2004. Test method for air permeability of textile fabrics, ASTM International, West Conshohocken, PA.

21.

Stanković

Popović

Poparić

. Thermal properties of textile fabrics made of natural and regenerated cellulose fibers. Polym Test 2008; 27: 41–48.

22.

EN 12667:2001. Thermal performance of building materials and products-Determination of thermal resistance by means of guarded hot plate and heat flow meter methods. Products of high and medium thermal resistance.

Development,characterization and thermal performance of insulating nonwoven fabrics made from textile waste

Abstract

Keywords

Introduction

Materials and methods

Textiles waste

Manufacturing insulation nonwoven

Thickness, mass per unit area, density and air permeability

Thermal conductivity and thermal resistance

Thermal performance of the nonwovens using test cell

Test cell description and measurement devices

The thermal transmission coefficient of insulating walls

Results and discussion

Analysis of the thickness, mass per unit area, density and air permeability of insulation nonwoven

Analysis of the thermal conductivity and thermal resistance of insulation nonwoven

Analysis of the thermal performance using test cell

Operative conditions

Calibration test

Thermal performance of the insulating walls

Conclusion

Footnotes

Declaration of conflicting interests

Funding

References