Acoustical Behavior of Treated Wood Dust-Filler for Polymer Foam Composite

2013 ◽  
Vol 465-466 ◽  
pp. 1039-1043 ◽  
Author(s):  
Shafizah Sa'adon ◽  
Anika Zafiah Mohd Rus
Keyword(s):  
Particle Size ◽  
Absorption Coefficient ◽  
Pore Size ◽  
Sound Absorption ◽  
Treated Wood ◽  
Sound Absorption Coefficient ◽  
Dust Particles ◽  
Wood Dust ◽  
Polymer Foam ◽  
Foam Composite

Wood dust filler-polymer foam composite has been studied and proved to have ability to absorb sound. In this study, treated rubber and Meranti wood dust named as RA and MA respectively was use as the filler. This study was developed to compare the behavior of sound absorption based on treated filler and particle size of wood dust. By choosing the size of 355 and 710 μm, three different percentages has been selected which is 10%, 15% and 20% for both type of wood dust. These samples has been tested by using Impedance Tube test for sound absorption coefficient (α) measurement and Noise Reduction Coefficient measurement (NRC) and Scanning Electron Microscopy (SEM) to determine the diameter of pore for selected size and type of wood dust-polymer foam composite. The pore size and structure was influence the sound absorption behavior of each sample. 355 μm-polymer foam composite of every percentage loading shows the uniform pore structure as compared to 710 μm of particle size. NRC results shows that increasing pore size has decrease the NRC value. It is therefore, concluded that the sound absorption coefficient for eachsound absorbing material, with different sizes of wood dust particles, types of wood dust and the percentages of wood dust loading in polymer foam matrix effect the sound absorption behavior.

Utilization of Treated Red Meranti Wood Dust as Polymer Foam Composite for Acoustic Study

2013 ◽  
Vol 594-595 ◽  
pp. 760-764 ◽  
Author(s):  
Shafizah Sa'adon ◽  
Anika Zafiah M. Rus
Keyword(s):  
Absorption Coefficient ◽  
Sound Absorption ◽  
Sound Absorption Coefficient ◽  
Wood Dust ◽  
Polymer Foam ◽  
Tube Test ◽  
Acoustic Study ◽  
Foam Composite ◽  
Absorbing Materials ◽  
Scanning Electron

A Red Meranti Wood Dust (RMD) act as a filler for polymer foam composite has been investigated and proved to have ability to absorb sound. In this study, treatment of wood dust with and without acid hydrolysis named as WDB and WDA respectively was use as filler. This study was developed to compare the ability of sound absorption based on treated filler and particle size of wood dust. By choosing the size of 355 μm, three different percentage has been selected which is 10%, 15% and 20% for both conditions. These samples has been tested by using Impedance Tube test according to ASTM E-1050 for sound absorption coefficient, α measurement and Scanning Electron Microscopy (SEM) for determine the porosity for each samples. 10% loaded of WDB as filler gives highest sound absorption coefficient of 0.999 at 4015.63 Hz. Meanwhile for 20% loaded of WDA gives 0.997 at 3228.13 Hz. When comparing the sound absorption coefficient for both sounds absorbing materials, WDB-polymer foam composite RMD showed higher value of sound absorption coefficient, α at higher frequency as compared to WDA-polymer foam composite.

UTILIZATION OF OIL PALM TRUNK (ELAEIS GUINEENSIS) AS FOAM COMPOSITE FOR SOUND ABSORPTION

2015 ◽  
Vol 77 (32) ◽  
Author(s):  
Shafizah Sa’adon ◽  
Anika Zafiah M. Rus
Keyword(s):  
Absorption Coefficient ◽  
Oil Palm ◽  
Sound Absorption ◽  
Elaeis Guineensis ◽  
Filler Loading ◽  
Sound Absorption Coefficient ◽  
Polymer Foam ◽  
Oil Palm Trunk ◽  
Frequency Level ◽  
Foam Composite

Oil Palm Trunk (OPT) act as a filler for polymer foam composite has been investigated and proved to have ability to absorb sound. In this study, treatment of wood untreated and treated with acid hydrolysis named as UP5 and TP5 was use as filler. This study was developed to compare the ability of sound absorption based on different composition of filler in polymer foam composite. By choosing the size of <500 µm, three different percentage has been selected which is 10 %, 15 % and 20 % for both conditions. These samples has been tested by using Impedance Tube test according to ASTM E-1050 for sound absorption coefficient, α measurement and Scanning Electron Microscopy (SEM) for determine the porosity for each  samples. 20 % filler loading of UP5 gives highest sound absorption coefficient of 0.97 at 4728 Hz. Meanwhile for 20 % loaded of TP5 gives 0.99 at 3371 Hz. When comparing the sound absorption coefficient for both sounds absorbing materials, TP5 polymer foam composite showed higher value of sound absorption coefficient, α at lower frequency level (Hz) as compared to UP5 polymer foam composite which gives better results in sound absorption.

scholarly journals Air permeability and sound absorption coefficient changes from ultrasonic treatment in a cross section of Malas (Homalium foetidum)

2021 ◽  
Vol 67 (1) ◽  
Author(s):  
Chun-Won Kang ◽  
Eun-Suk Jang ◽  
Nam-Ho Lee ◽  
Sang-Sik Jang ◽  
Min Lee
Keyword(s):  
Absorption Coefficient ◽  
Ultrasonic Treatment ◽  
Sound Absorption ◽  
Gas Permeability ◽  
Treated Wood ◽  
Untreated Wood ◽  
Sound Absorption Coefficient ◽  
Permeability Constant ◽  
Average Value ◽  
Permeability Increase

AbstractWe investigated the effect of ultrasonic treatment on Malas (Homalium foetidum) gas permeability and sound absorption coefficient using the transfer function method. Results showed a longitudinal average Darcy permeability constant of 2.02 (standard deviation SD 0.72) for untreated wood and 6.15 (SD 3.07) for ultrasound-treated wood, a permeability increase of 3.04 times. We also determined the average sound absorption coefficients in the range of 50 to 6.4 kHz and NRC (noise reduction coefficient: average value of sound absorption coefficient value at 250, 500, 1000, and 2000 Hz) of untreated Malas. Those values were 0.23 (SD 0.02) and 0.13 (SD 0.01), respectively, while those of ultrasonic-treated Malas were 0.28 (SD 0.02) and 0.14 (SD 0.02), a 19.74% increase in average sound absorption coefficient.

Sound Absorption Characteristics of Porous Steel Manufactured by Lost Carbonate Sintering

2009 ◽  
Vol 1188 ◽  
Author(s):  
Miao Lu ◽  
Carl Hopkins ◽  
Yuyuan Zhao ◽  
Gary Seiffert
Keyword(s):  
Absorption Coefficient ◽  
Pore Size ◽  
Sound Absorption ◽  
Single Layer ◽  
Normal Incidence ◽  
Sound Absorption Coefficient ◽  
Absorption Coefficients ◽  
Impedance Tube ◽  
Absorption Characteristics

AbstractThis paper investigates the sound absorption characteristics of porous steel samples manufactured by Lost Carbonate Sintering. Measurements of the normal incidence sound absorption coefficient were made using an impedance tube for single-layer porous steel discs and assemblies comprising four layers of porous steel discs. The sound absorption coefficient was found not to vary significantly with pore size in the range of 250-1500 μm. In general, the absorption coefficient increases with increasing frequency and increasing thickness, and peaks at specific frequencies depending on the porosity. An increase in porosity tends to increase the frequency at which the sound absorption coefficient reaches this peak. An advantage was found in using an assembly of samples with gradient porosities of 75%-70%-65%-60% as it gave higher and more uniform sound absorption coefficients than an assembly with porosities of 75%.

Sound Absorption Behavior of Porous Al Produced by Spacer Method

2006 ◽  
Vol 15-17 ◽  
pp. 422-427
Author(s):  
Tetsumune Kuromura ◽  
Masataka Hakamada ◽  
Y. Chen ◽  
Hiromu Kusuda ◽  
Mamoru Mabuchi
Keyword(s):  
Absorption Coefficient ◽  
Pore Size ◽  
Sound Absorption ◽  
Size Range ◽  
Absorption Capacity ◽  
The Other ◽  
Sound Absorption Coefficient ◽  
Specimen Thickness ◽  
Pore Sizes ◽  
Other Hand

Porous Al specimens with a pore size range from 212-300 to 610-700 μm, a porosity from 85 to 95% and a specimen thickness from 2 to 20 mm were produced by the spacer method, and their sound absorption capacity was investigated. For these specimens, sound absorption coefficient increased with increasing porosity. On the other hand, sound absorption coefficient varied inconsistently with the variation of pore sizes. The latter may be attributed to variation of aperture sizes of each specimen because the porous Al specimens with differerent pore sizes produced by the spacer method should have different aperture sizes. Sound absorption coefficient increased at the frequency below 2000 Hz with increasing specimen thickness.

scholarly journals Investigation of Sound Absorption Properties of Heat-Treated Indonesian Momala (Homalium foetidum (Roxb.) Benth.) and Korean Red Toon (Toona sinensis (A. Juss.) M. Roem.) Cross Sections

Forests ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1447
Author(s):  
Eun-Suk Jang ◽  
Chun-Won Kang
Keyword(s):  
Heat Treatment ◽  
Absorption Coefficient ◽  
Pore Size ◽  
Cross Sections ◽  
Sound Absorption ◽  
Gas Permeability ◽  
Sound Absorption Coefficient ◽  
Absorption Function ◽  
Toona Sinensis ◽  
Heat Treated

This study investigates the effects of heat treatment time and presence of an air back cavity on the sound absorption performance of Indonesian momala (Homalium foetidum (Roxb.) Benth.) and Korean red toon (Toona sinensis (A. Juss.) M. Roem.) cross sections. To examine the porous characteristics of the two species before and after heat treatment, gas permeability, pore size, and porosity analyses were conducted. Additionally, the sound absorption coefficient was measured based on various heat treatment times and air back cavity sizes. The results showed that, with heat treatment at 210 °C for 6 h, the gas permeability improved by 4.3% for the momala and 38.5% for the red toon, the maximum pore size was improved by 5.25% in the momala and 26.0% in the red toon, and the through-pore porosity improved by 22.7% for the momala and 117.0% for the red toon. Due to these pore structure changes, the noise reduction coefficient (NRC) of the heat-treated momala improved by 6.8%. When a 3-cm air back cavity was applied to the heat-treated momala, the NRC was improved to 92.5%. Similarly, when the same air back cavity was applied to the heat-treated red toon, the NRC was improved to 190.7%. This study demonstrated that an increase in pore size and through-pore porosity by heat treatment triggered an increase in the sound absorption coefficient. Additionally, when an air cavity was applied, the sound absorption coefficient of both heat-treated wood species was increased at low frequency. From the results of this study, we expected that heat-treated momala and red toon cross-sections can be utilized as eco-friendly ceiling materials with sound absorption function.

scholarly journals Investigation of Acoustic Properties of Poroelastic Asphalt Mixtures in Laboratory and Field Conditions

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2649
Author(s):  
Wladyslaw Gardziejczyk ◽  
Piotr Jaskula ◽  
Jerzy A. Ejsmont ◽  
Marek Motylewicz ◽  
Marcin Stienss ◽  
...  
Keyword(s):  
Particle Size ◽  
Absorption Coefficient ◽  
Sound Absorption ◽  
Asphalt Mixtures ◽  
Acoustic Properties ◽  
Sound Absorption Coefficient ◽  
Void Content ◽  
Laboratory Conditions ◽  
Air Void ◽  
Air Void Content

Measures for the improvement of acoustic conditions in the vicinity of roads include the construction of pavement structures with low-noise surfaces with optimal macrotexture and the highest possible sound absorption coefficient. Laboratory evaluation of acoustic properties of a designed asphalt mixture before its placement in the pavement is a good solution. Currently, the most popular method for the determination of the sound absorption coefficient of various construction materials under laboratory conditions is the Kundt’s tube test. Sound absorption coefficient can also be assessed based on field and laboratory measurements performed using a Spectronics ACUPAVE System. Other parameters characterising the acoustic properties of road pavement courses include air void content and water drainability or permeability. The article presents an analysis of results of sound absorption coefficient obtained using a Spectronics ACUPAVE System and water drainability and permeability of poroelastic mixtures obtained both in laboratory and on test sections, in relation to air void content and grading of the mixtures. It was established that poroelastic mixtures containing an aggregate of maximum particle size of 5 mm are characterised by better acoustic properties than mixtures with a maximum aggregate particle size of 8 mm. Changes of crumb rubber aggregate grading and bitumen type (within the tested range of values) as well as the addition of lime have shown no evident influence on the sound absorption coefficient. Noise level values at the speed of 30 km/h according to the CPX method were measured as well. Relationships between sound absorption coefficient, water drainability/permeability, and air void content were determined. The performed analyses confirmed that Spectronics ACUPAVE System may be applied for evaluation of acoustic properties of asphalt mixtures in laboratory conditions, but further research is needed to reduce the uncertainty of the results.

scholarly journals Development and Characterization on sound acoustic at photo-induced polymer foam composited at prolonged ultra-violet exposure

2018 ◽  
Vol 7 (4.33) ◽  
pp. 479
Author(s):  
M. Taufiq Zaliran ◽  
Anika Zafiah M. Rus ◽  
Shaharuddin Kormin ◽  
M Shafiq M Azahari
Keyword(s):  
Absorption Coefficient ◽  
Pore Structure ◽  
Sound Absorption ◽  
Size Structure ◽  
Ultra Violet ◽  
Filler Loading ◽  
Sound Absorption Coefficient ◽  
Polymer Foam ◽  
Fibre Filler ◽  
The Stability

In this paper, polymer foam composites (FC) have been developed based on polyol mixed flexible crosslinker and fibre filler of Meranti Merah. 10 mm, 20 mm and 30 mm thickness of foam polymer and its composites have been use in this study. The percentage loading of wood fibre of 5%, 10%, 15% and 20% added with polymer foam is namely as polymer foam (PP) and its composites of PP5, PP10, PP15 and PP20. The sound absorption coefficient (α) and pore structure of the foam samples have been measure by using Impedance Tube test and Scanning Electron Microscopy (SEM). UV Weatherometer is used to examine the durability and weatherproof of its composite. The results show that the highest thickness of the highest percentage fiber filler (Pp2030) gives higher sound absorption coefficient (α). 0.9922 and 0.99889 which contributed from low and high frequency absorption level respectively. The smallest pores size structure was observed with highest filler loading of PP20. The higher the thickness and the higher the percentage loading of wood filler gives smaller pore structure, consequently, increased the sound absorption coefficient level. Meanwhile, the stability of polymer foam composites is high due to unchanged pore structures morphology with prolonged ultra violet exposure.  

scholarly journals Koefisien Serap Bunyi Papan Partikel Dari Bahan Serbuk Kayu Kelapa

Jurnal MIPA ◽  
2013 ◽  
Vol 2 (1) ◽  
pp. 56
Author(s):  
Thamrin Suhaemi ◽  
Seni H. J. Tongkukut ◽  
As'ari .
Keyword(s):  
Absorption Coefficient ◽  
Sound Absorption ◽  
Base Material ◽  
Sample Thickness ◽  
Sound Absorption Coefficient ◽  
Wood Dust ◽  
Particle Board ◽  
Absorption Coefficients ◽  
Board Thickness

Telah dilakukan penelitian untuk mengetahui karakteristik koefisien serap bunyi papan partikel dari bahan dasar serbuk kayu kelapa. Papan partikel dibuat dengan mencampur serbuk kayu kelapa dengan tepung kanji, dicetak, dan dikeringkan. Sampel berbentuk silinder, dibuat sebanyak 4 buah dengan tebal : (1,15 cm), (1,95 cm), (2,95 cm) dan (4,05 cm). Nilai koefisien serap bunyi sampel diukur menggunakan alat ukur koefisien serap bunyi. Hasil penelitian menunjukkan, ketebalan sampel mempengaruhi nilai koefisien serap bunyi (α) yaitu pada frekuensi 600 Hz. Koefisien serap bunyi (α) semakin menurun dengan bertambahnya ketebalan papan partikel (sampel penyerap).The research had been doing to know characteristic sound absorption coefficient of particle board which made from base material coconut wood dust. The particle board made by mix of coconut wood dust with cornstarch then pressed and dried. The particle board as a sample is cylinder with diameter 8,5 cm. The thick of four samples are 1,15 cm, 1,95 cm, 2,95 cm, and 4,15 cm. The sound absorption coefficient have measured by sound absorption coefficient instruments. The result is sample thickness has influence to sound absorption coefficient values such as at 600 Hz frequencies. Sound absorption coefficients is decreasing to the increasing of the particle board thickness (absorber sample).

Effect of characterization of porous metal fiber media on sound absorption coefficient

2015 ◽  
Vol 29 (10n11) ◽  
pp. 1540002 ◽  
Author(s):  
J. Z. Wang ◽  
Q. B. Ao ◽  
H. P. Tang ◽  
T. F. Bao
Keyword(s):  
Absorption Coefficient ◽  
Pore Size ◽  
Sound Absorption ◽  
Fiber Diameter ◽  
Average Pore Size ◽  
Porous Metal ◽  
International Standards ◽  
Sound Absorption Coefficient ◽  
Metal Fiber ◽  
Average Pore

Porous metal fiber media (PMFM) is a kind of advanced structural and functional material, and it has attracted a wide spread attention owing to excellent sound absorption performance. The sound absorption property of PMFM is mainly influenced by the fiber diameter, the average pore size and thickness of PMFM. In the paper, three stainless steel fibers with the diameters (∅) of 8, 12 and 20 μm were used to make PMFM with the average pore sizes of 10, 20, 30 and 40 μm and the thicknesses of 1, 2 and 3 mm by air-laid and sintering processes. The sound absorption coefficients of PMFM were tested in impedance tube using two-microphone transfer-function method according to ISO 10534-2 and ASTM E1050-98 international standards at room temperature. The results show that when the frequency ranges from 50 Hz to 6,400 Hz in material with the average pore size of 20 μm and the thickness of 3 mm and the fiber diameter of ∅8 μm, the average sound absorption coefficient is the highest.

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