PROCEEDINGS of the23rd International Congress on Acoustics
9 to 13 September 2019 in Aachen, Germany

Characterization of woven fabrics for developmentof micro perforated panel absorbers
Gunawan1,2; I Prasetyo1; B Yuliarto1; K Anwar1; D R Andhika1;
1Engineering Physics, Faculty of Industrial Technology, Institut Teknologi Bandung, Indonesia
2

Textile Engineering, Politeknik STTT Bandung, Indonesia

ABSTRACT
Woven Fabrics are potentially to be developed as a sound absorber system because of the presence of micro
perforation on their surface. By introducing air cavity backing the woven fabrics up, such system can undergo
Helmholtz resonator mechanism as found in micro-perforated panel absorber. The micro perforations in awoven fabric are formed by yarn in x (weft) and y (warp) direction. The perforations can create aviscos-inertial effect when interact with sound fields that is useful as a basis for sound absorption mechanism.
In this study, we focused on investigating the relationship of woven fabric material and manufacturing
technique properties to associated sound absorption characteristics. For this, natural, semi-synthetic andsynthetic fibers-based yarn are used to produce woven fabrics. For further investigation, the geometrical andphysical properties of the yarns and fabrics are characterized. The geometrical properties are characterizedusing a digital microscope while the physical properties are measured using a fabric air permeability, finenessyarn, and other textiles testing devices. Meanwhile, the sound absorption coefficients are evaluated by animpedance tube using transfer function method. From this study, it can be concluded that the soundabsorption coefficients of woven fabric are affected by material and manufacturing technique properties. It isexpected that the results can be beneficial for developing design procedure of development woven fabricbased on micro perforated panel absorber system.
Keywords: woven fabric, micro perforation, sound absorption, natural, semi-synthetic and synthetic yarns.

1. INTRODUCTION
Noise pollution is one of the problem for human and environment [1, 2]. Woven fabrics as acoustic
absorbers have been used as an absorber material. The relationship of some parameters on woven
carpet to sound absorption has been investigated by many researcher [3, 4, 5, 6]. Several experiments
have been carried out by varying the structure and density of woven fabric with absorption coefficient
below 0.6 [7, 8]. Multiple regression has been used to analyze sound absorption on woven fabric [9].
The combination of woven fabric with other material such as non-woven, felt, foam, knitted fabric,membrane, etc. has been carried out to improve sound absorption [10, 11, 12]. Some prediction models
have been developed related to the woven fabric material [13, 14, 15]. Prediction sound woven fabrics
have been formulated based on JCA formulation [16].
In further development, it is important to improve woven fabrics by exploiting the perforation inthat presence inherently on woven fabric. Because of the presence of micro-perforation on the surface,woven fabric has a basis for a viscos-inertial effect that is important as a micro-perforated panel [17]Some effort have been carried out to exploit perforation to have micro size. The application of facile
dip-coating method was carried out to improve micro-perforated on woven fabric [18]. Textilecomposite material was drilled into micro sized to have a benefit on structure and sound absorption
properties [19].

13458

gunawan_tf_s3@students.ac.id and gunazka@gmail.com

Maa has developed theory and model to predict sound absorption on micro-perforated panel (MPP)[20, 21, 22]. The most important parameter is the perforate constant k, acoustic resistance r andfrequency fo . Maa also suggests to make minute holes 01-0.3 mm for having wide-band absorption up
to 3-4 octaves and for low–frequency absorption with a cavity of depth small compared to thewavelength.
In this experiment, woven fabric was developed by variation on yarn and manufacturing techniqueproperties to improve perforation to be smaller in micro size. Yarns were varied based on yarn counts
and fiber type (natural, semi-synthetic and synthetic. The purpose of the research is to investigate therelationship between yarn and weft density on absorption coefficient that is very important indeveloping micro-perforated panel. Maa’s model was used to compare between measurement andprediction.

2. MATERIAL AND METHODS
2.1 MaterialsThere were 8 combination fabrics from different yarns based on natural, semi-synthetic andsynthetic fibers. Table 1 shows yarn properties of woven fabric that use as weft yarn (x direction). TR(Rayon 35% - Polyester 65%) yarns with count number Ne 1 20 were used for all warp yarns (ydirection).
In the manufacturing process, the density of woven fabric consists of the number of warp and weftyarns in inch. The warp density for all woven fabrics are 98 yarns/inch. The weft density were varied
from 20, 25, 30, 35, 40, 45, 50, 55, 60, 65 and 70 yarns/inch. The structure for all woven fabrics were
Twill 3/1.
Table 1 - Yarn properties
Yarn

Category Fiber

Yarn countDiameter (mm)CottonNaturalNe1 32/20,488

Wool

NaturalNm 30/2

0.667

Nylon

synthetic

210 D

0.670

Acrylicsynthetic

Nm 32/2

0.587

PE (Polyester spun)

synthetic

Ne1 100.424

PE (Polyester spun)

synthetic

Ne1 200,352

Polyester (filament)

synthetic

75 D

0.429

Semi-synthetic

Ne1 200.357

TR (65% Polyester35% Rayon)
2.2Methods
The air permeability was measured using a fabric air permeability instrument (Textest FX 3300
LabAir IV) according to ISO 9237 (Textile Determination of the Permeability of fabrics to air). Thethickness was measured using a fabric thickness tester (Teclock) according to ISO 5084 (Textile
Determination of thickness textiles and textile products). The geometrical properties are characterizedusing a digital microscope. Figure 1 shows magnification image sample woven fabric by a digital
microscope.
Absorption coefficient was measured was measured by impedance tube (BSWA SW477) usingtransfer function method according to ISO 10534-1:2001 (Acoustics-Determination of soundabsorption coefficient and impedance tubes-Part 1; Method using standing wave ratio). The circular
woven fabrics with a diameter of 30 mm and 100 mm were measured to obtain coefficient absorption
at low, medium and high frequency. The air gap was 15 mm for all measurement.

3459

(a) Cotton(b) Polyester(c) Wool(d) Nylon

Figure 1-Magnification of image sample woven fabric by digital microscope

3. RESULTS AND DISCUSSIONS
3.1 Effect of yarn on acoustic absorption
Figure 1 shows acoustic absorption of woven fabrics with natural, semi-synthetic and synthetic
fiber-based yarn with the same number density of 20 weft yarn/cm (x direction) and 40 warp yarn/cm(y direction). Woven fabric from natural fiber-based yarn has a good sound absorption. From low until
mid-frequency, wool fabrics have the highest absorption coefficient with the lowest diameter
perforation of 0.05 mm. At the frequency of 3000 Hz wool fabrics have the highest absorption
coefficient 0.96 and then gradually decrease until reach the absorption coefficient of 0.29 at thefrequency 6300 Hz. Meanwhile, cotton woven fabric has also good performance of the sound onabsorption. Cotton woven fabric has the highest absorption coefficient of 0.96 at the frequency of 4250
Hz.
Table 2 – Physical properties of woven fabrics with 20 weft and 40 warp density
Diameter Perforation

Air Permeability(mm)(cm/s)

208

0.17

68.2

Wool Nm 30/2

288

0.05

29.1

Acrylic Nm 32/2

292

0.05

10.2

Nylon 210 D

295

0.08

44.7

Polyester 75 D

1840.17

100.0

PE Ne1 102580.15

78.1

PE Ne1 20

1890.1779.4

TR Ne1 20

187

0.17

87.7

FabricWeight (g/m2)

Cotton Ne1 32/2

Nylon woven fabric as synthetic yarn has the highest absorption from mid until high frequency thanthe other woven fabrics. Nylon woven fabric has the highest absorption coefficient of 1.00 at thefrequency of 3350 Hz and 3550 Hz. Although the absorption coefficient of nylon fabric after the mid
frequency gradually decreases, but it still has the absorption coefficient of 0.73 at the frequency of6300 Hz. Polyester woven fabric has the lowest sound absorption than the others. Semi -synthetic TR
woven fabric, based polyester and viscous fiber, has medium performance. It has the highest
absorption coefficient of 0.86 at the frequency of 4500 Hz.

3460

1,00,9Absorption Coefficients

0,80,70,60,50,40,30,20,10,001000
Cotton Ne1 32/2
PE Ne1 20

2000

3000
4000
Frequency (Hz)Wool NM 30/2
Nylon 210D

TR Ne1 20
Polyester 75D

50006000

PE Ne1 10Acrilic NM 32/2

Figure 2- Effects of yarn count and fiber based on sound absorption characteristics

Absorption coefficientsThe other property of yarn that is also important in the manufacturing of woven fabric is yarn count.
Figure 2 shows the absorption coefficient of woven fabrics from the same polyester yarn (PE) withdifferent yarn count. Yarn count indicates the mass per unit length or the length per unit mass. It
expresses the fineness or coarseness of yarn. It can be seen from low until high frequen cy absorption
coefficient between yarns almost the same. At the frequency of 5000 Hz, the absorption coefficient ofboth yarns are 0.83 and 0.84. The sound absorption of both yarns show the difference after thefrequency of 5000 Hz. Woven fabric with yarn count Ne 1 20 has higher absorption coefficient than Ne 1
10. The higher the yarn count the finer the yarn is.
1,00,90,80,70,60,50,40,30,20,10,0

PE Ne1 10PE Ne1 2001000

2000

3000

4000

5000

6000

7000

Frequency (Hz)Figure 3-Sound absorption polyester woven fabrics with different yarn counts
It is also interesting to show different yarns with the same yarn counts. Figure 3 shows theabsorption coefficient of woven fabrics from the same yarn counts, Ne 1 20, with different fiber. It canbe seen that woven fabrics from synthetic yarn of 100% Polyester (PE) has a slightly higher soundabsorption than the semi-synthetic yarn of 65% Polyester 35% Rayon (TR) especially at 2000 Hz untilhigh frequency. This effect must be further investigated more detailed to have better understanding thesignificance and the properties of yarns that contribute to the absorption coefficient.

3461

1,0PE Ne1 20
TR Ne1 200,9Absorption coefficients

0,80,70,60,50,40,30,20,10,00

1000

2000

3000
4000
Frequency (Hz)

5000

6000

7000

Figure 4-Sound absorption woven fabrics with different fiber
3.2 Effects of weft density on acoustic absorption
The geometry woven fabric can be affected by the yarn density in the stru cture of woven density.
Yarn density is a number of weft and warp yarn in square (cm). In this experiment, warp density isconstant of 40 warp yarn per cm but weft density (TP) was varied. Figure 4 show effect weft density on
acoustic absorption in TR woven fabric. The form of sound absorption all woven fabric are curve. It
can be seen that the increasing of the weft density results in increasing sound absorption. In the
mid-to-high frequency, weft density TP 65 has the highest curve sound absorption an d the lowest for
weft density TP 20. The highest absorption coefficient 0.98 was obtained at frequency 3750 Hz by weftdensity TP 65. It is also interesting althought the weft density TP 70 is the highest weft density but in
mid-to-high frequency performance sound absorption under weft density TP 65.
Table 3 – Material properties of woven fabric TR Woven FabricFabric3462

Weft density(yarn/cm)

Diameter
Perforation

Weight (g/m2)(mm)

Air Permeability(m3/m2/s)

TP 20

80.342144

3.3750TP 25

100.292

153

2.7970TP 30

120.240160

2.3200TP 35

140.218166

1.8780TP 40

160.200172

1.4770TP 45

180.171180

1.1090TP 50

200.167

1870.8774

TP 55

220.151

195

0.634

TP 60

240.135

2030.4348

TP 65

260.1212100.3572

TP 70

280.1032190.2221

Variation in weft density will change the perforation. Perforation in woven fabric is formed by theintersection between weft and warp yarn. When weft density increases, it makes perforations smaller.
The smaller perforations create more a viscos-inertial effect when interacting with sound fields thatare useful in sound absorption mechanism.
1,0Absorption coefficients

0,90,80,70,60,50,40,30,20,10,00

1000

2000

3000
4000
Frequency (Hz)

5000

TP 20

TP 25

TP 30

TP 35

TP 40

TP 50

TP 55

TP 60

TP 65

TP 70

6000
TP 45

Figure 5-Effect weft density on sound absorption woven fabric
3.3 Prediction by Maa’s model
Maa’s model is used to analyze the sound absorption of woven fabrics. Table 3 shows the diameterand perforation ratio as input parameter in Maa’s model. Figure 5 shows the measurement andprediction by Maa’s model for TR 20 Woven Fabric with air cavity 15 mm. It can be seen from thefigure that for TP 70 Maa’s model can well predict behavior of absorption coefficients, but for TP 65
there are a slightly gaps between measurement and model. Further development must be carried out tosolve the gap. Overall this result is important as a basis to develop of woven fabrics based on micro
perforated panel absorber system.
Table 3 – Physical properties of woven fabric TR Woven FabricFabricWeft density(yarn/cm)

Diameter
Perforation(mm)

Perforation Ratio
(%)

TP 65

260.121

4.12

TP 70

280.103

3.33.

3463

(a) Weft density TP 70(b) Weft density TP 65

Figure 6- Validation results using Maa’s model Prediction (--) and Measurement (--)

4. CONCLUSIONSIn this study, it can be concluded that yarn and weft density affect to the sound absorption
coefficients of woven fabric. Overall, woven fabrics have a potential as absorber based micro
perforated panel system. It is important to have a range for amplitude and bandwidth in which the yarn
and material come into play. The development of MPP based on woven fabrics is rather different fromthat of the conventional from solid material. Moreover, Maa’s model is not always successful topredict its behavior. Hence, it is suggested to improve the model.

ACKNOWLEDGEMENTS
This work was funded by ITB research grant. The first author is also grateful to Politeknik STTT
Bandung for providing the machine to fabricate the measurement samples.

REFERENCES[1]

E. Kerns, C. L. Themann, E. A. Masterson and G. M. Calvert, "Cardiovascular conditions, hearing
difficulty, and occupational," American Journal of Industrial Medicine, pp. 1-15, 2018.

[2]

N. Pignier, "The impact of traffic noise on economy and environment: a short literature study," TheCentre for ECO2 Vehicle Design KTH Aeronautical and Vehicle Engineering, Stockholm, Sweden,
2015.

[3]

M. Küçük and Y. Korkmaz, "Sound absorption properties of acrylic carpets," Journal Textile Institute,
2016.

[4]

A. Elkhateeb, A. Adas, M. Attia and Y. Balila, "Absorption characteristics of masjid carpets," AppliedAcoustics, pp. 143-155, 2015.

[5]

R. Ford and G. Bakker, "The acoustical properties of various carpet and underlay combinations,"
journal if the textile institute, pp. 164-174, 1983.

[6]

M. Nute and K. Slater, "a study of some factors affecting sound reduction by carpeting," The journalof the textile institute, pp. 645-651, 1973.

3464

[7]

P. Soltani and M. Zarrebini, "Acoustic performance of woven fabrics in relation to structuralparameters and air permeability," The Journal of The Textile Institute, 2013.

[8]

P. Soltani and M. Zerrebini, "The analysis of acoustical characteristics and sound absorption
coefficient of woven fabrics," Textile Research Journal, pp. 875-882, 2012.

[9]

X. Tang, D. Kong and X. Yan, "Multiple regression anlysis of a woven fabric sound absorber," Textile
Research Journal, pp. 1-12, 2018.

[10] J. J. Kim, H. J. Jeong and Y. J. Sohn, "Sound absorption characteristics of PTFE membrane Material
and their application to a multi-purpose stadium," Building Serv. Eng. Res. Technol. 30, pp. 213-226,2009.
[11] N. N. M. Hassan and A. Z. M. Rus, "Influences of thickness and fabric for sound absoption ofbiopolymer composite," Applied mechanics and material Vol. 393, pp. 102-107, 2013.
[12] M. S. Alcaraz, M. B. Aracil, . J. S. Alcaraz and I. M. Segul, "Sound absorption of textile materialusing a microfibres resistive layer," Material science and engineering 254, 2017.
[13] J. Kang and H. Fuchs, "Predicting the absorption of open weave textiles ang micro-perforated
membranes backed by an air space," Journal of sound and vibration, pp. 905-920, 1999.
[14] K. Byrne, "Calculating the acoustical properties of fabric constructions," Journal of Sound andVibration , pp. 423-435, 1998.
[15] L. Beranek, "Acoustical Properties of Homogeneous, Isotropic Rigid Tiles and Flexible Blankets,"
The Journal of the acoustical society of america, pp. 556-568, 1947.
[16] I. Prasetiyo, G. Desendera, M. Hermanto and D. R. Adhika, "On Woven Fabric Sound Absorption
Prediction," ARCHIVES OF ACOUSTICS, vol. 43, p. 707–715, 2018.
[17] G. Desendra, M. Hermanto, I. Prasetiyo and D. Adhika, "Experimental investigation of fabric-based
micro perforated panel absorber," Journal of Physics: Conf. Series 1075, pp. 1-5, 2018.
[18] X. Tang, D. Kong and X. Yan, "Facile dip-coating method to prepare micro-perforated fabric acoustic
absorber," Applied Acoustics, pp. 133-139, 2018.
[19] O. Onen and M. Caliskan, "Design of a single layer micro-perforated sound absorber by finiteelement analysis," Applied Acoustics, pp. 79-85, 2010.
[20] D. Maa, "Microperforated panel wideband absorbers," Noise control engineering Journal, vol. 29, pp.
77-84, 1987.
[21] D. Maa, "Potential of microperforated panel absorber," Journal Acoustic Society, pp. 2861-2866,
1998.
[22] D. Maa, "Theory and design of microperforated panel sound-absorbing constructions," pp. 55-71,
1975.

3465