Pekali Penyerapan Bunyi Dan Indek Kehilangan Penghantaran Panel Penyerap Bunyi Menggunakan Gentian Sabut Kelapa

2012 ◽  
Author(s):  
Rosli Zulkifli ◽  
Mohd Faizal Mat Tahir ◽  
Ahmad Rasdan Ismail
Keyword(s):  
Absorption Coefficient ◽  
Oil Palm ◽  
Sound Absorption ◽  
Transmission Loss ◽  
Frequency Range ◽  
Coir Fibre ◽  
Noise Absorption ◽  
Loss Index ◽  
Oil Palm Fibre ◽  
Palm Fibre

Kajian ini dilakukan untuk menentukan sifat akustik panel penyerap bunyi yang di rekabentuk menggunakan bahan gentian sabut kelapa melalui ujikaji dan simulasi. Perbandingan nilai pekali penyerapan bunyi antara bahan gentian sabut kelapa asli dan sabut kelapa yang dimasukkan kedalam panel komposit berlubang telah dibuat. Lapisan luar panel difabrikasi menggunakan panel komposit gentian asli/poliester manakala sabut kelapa terawat digunakan sebagai bahan penyerap bunyi. Panel diuji menggunakan piawaian ISO 354 bagi ujikaji pekali penyerapan bunyi manakala simulasi dijalankan menggunakan perisian WinFLAGTM. Ujian indek kehilangan penghantaran bagi panel penyerap bunyi menggunakan sabut kelapa telah dijalankan dan perbandingan dengan gentian kelapa sawit telah dibuat. Bagi ujikaji pengukuran indek kehilangan penghantaran, Piawaian ISO 717–1 telah digunakan sebagai piawaian. Bagi pekali penyerapan bunyi, hasil eksperimen memberikan nilai penyerapan di antara 0.70 dan 0.80 untuk julat frekuensi dari 1000 Hz sehingga 1800 Hz manakala nilai pekali yang diperoleh dari simulasi pula adalah 0.7 sehingga 0.85 bagi frekuensi berjulat 500 Hz sehingga 2500 Hz. Untuk ujian kehilangan penghantaran, purata indeks kehilangan penghantaran yang dicatatkan adalah 20 dB untuk panel yang mengandungi sabut kelapa dan 17 db untuk panel yang mengandungi gentian kelapa sawit. Hasil keputusan menunjukkan pekali penyerapan bunyi yang diperoleh melalui kaedah eksperimen dan simulasi memberikan nilai yang boleh dianggap baik dan setanding dengan bahan penyerap komersial di pasaran seperti gentian sintetik dan tatal batuan. Indeks kehilangan penghantaran bagi panel yang gentian sabut kelapa pula adalah lebih baik berbanding panel yang mengandungi gentian kelapa sawit. Kata kunci: Bahan akustik; sabut kelapa; pekali penyerapan bunyi; indek kehilangan penghantaran; bilik gema This study was carried out to determine the acoustic properties of a noise absorption panel that was designed to use a coir fibre as noise absorption materials through experimental test and simulation. Comparison of noise absorption coefficient between natural coir fibre and coir fibre inserted inside a perforated panel have been carried out. The outer layer of the panel was fabricated using a coir fibre/polyester composites and treated coir fibre was used as absorption materials. The panel has been tested using ISO 354 standard for noise absorption coefficient while the simulation was carried out using WinFLAGTM software. The transmission loss index test for panel using coir fibre has been carried out and the results was compared with panel using an oil palm fibre. For the transmission loss index, ISO standard 717–1 was used. Experimental results for the noise absorption coefficient give coefficient values between 0.70 and 0.80 for frequency range of 1000 Hz to 1800 Hz while the results from simulation give a coefficient between 0.7 to 0.85 for frequency range of 500 Hz to 2500 Hz. For the transmission loss test, average transmission loss recorded was 20 dB for the panel using coir fibre and 17 dB for panel using an oil palm fibre. Results obtained shows that sound absorption coefficient obtained through experimental test and simulation were very good and comparable with the commercial noise absorption material such as synthetic fibre and rock wool. Transmission loss index for the panel using coir fibre gives a better results compared to panel using oil palm fibre. Key words: Acoustic materials; coir fibre; sound absorption coefficient; tranmission loss index; reverberation room

Sound Absorption Characteristics of Composite Panel Made from Coconut Coir and Oil Palm Empty Fruit Bunches Fibre with Polyester

2021 ◽  
Vol 18 (3) ◽  
pp. 9022-9028
Author(s):  
M. Rusli ◽  
R.S. Nanda ◽  
H. Dahlan ◽  
M. Bur ◽  
M. Okuma
Keyword(s):  
Absorption Coefficient ◽  
Oil Palm ◽  
Sound Absorption ◽  
Natural Fibre ◽  
Composite Panel ◽  
Frequency Range ◽  
Empty Fruit Bunches ◽  
Coir Fibre ◽  
Coconut Coir ◽  
Absorption Characteristics

The development of pure natural fibres as sound absorptive material remains overlooked due to their lack of mechanical and moist properties, low durability, and vulnerability to be damaged by the environment. Certain fibre treatments are needed to improve such disadvantages. This paper investigates sound absorption characteristics of coconut fibre (coir) and oil palm fibre made from empty fruit bunches (OPEFB) fibre bonded by polyester that can protect them from the ambient environment in order to increase their durability. Two types of fibre-polyester composites have been tested. The first is the fibre-polyester composite (FPC) type, which is totally coated with polyester as the composite matrix. Another type is the fibre-polyester bonded composite (FPBC), in which the polyester is brushed into slice by a slice of the fibre layer in order to coat and bond the fibre, although porous among the fibre remains possible. A two-channel impedance tube is used in the measurement within 200 Hz to 3000 Hz of the frequency range. It is found that FPBC type panel has almost similar sound absorption characteristics to its purely natural fibre as it is able to maintain the panel porosity. The coconut coir fibre panel and its composite have a maximum absorption coefficient of almost 100% within the frequency range 1500-2000 Hz, considerably better than the OPEFB fibre, with only about 80% of the absorption coefficient. If the FPC layer exists, the sound absorption is reduced, and the frequency peaks are also shifted. Additions of the FPC panel layer thickness produced lower sound absorptions and shifted the peaks to the lower frequency range. The FPBC panel type is viable to protect the fibre from the environment without changing its sound absorption characteristics.

scholarly journals Non-Wovens as Sound Reducers

2018 ◽  
Vol 55 (2) ◽  
pp. 64-76
Author(s):  
D. Belakova ◽  
A. Seile ◽  
S. Kukle ◽  
T. Plamus
Keyword(s):  
Absorption Coefficient ◽  
Surface Density ◽  
Sound Absorption ◽  
Transmission Loss ◽  
Sound Transmission ◽  
Sound Insulation ◽  
Material Structure ◽  
Sound Transmission Loss ◽  
Sound Waves ◽  
Frequency Range

Abstract Within the present study, the effect of hemp (40 wt%) and polyactide (60 wt%), non-woven surface density, thickness and number of fibre web layers on the sound absorption coefficient and the sound transmission loss in the frequency range from 50 to 5000 Hz is analysed. The sound insulation properties of the experimental samples have been determined, compared to the ones in practical use, and the possible use of material has been defined. Non-woven materials are ideally suited for use in acoustic insulation products because the arrangement of fibres produces a porous material structure, which leads to a greater interaction between sound waves and fibre structure. Of all the tested samples (A, B and D), the non-woven variant B exceeded the surface density of sample A by 1.22 times and 1.15 times that of sample D. By placing non-wovens one above the other in 2 layers, it is possible to increase the absorption coefficient of the material, which depending on the frequency corresponds to C, D, and E sound absorption classes. Sample A demonstrates the best sound absorption of all the three samples in the frequency range from 250 to 2000 Hz. In the test frequency range from 50 to 5000 Hz, the sound transmission loss varies from 0.76 (Sample D at 63 Hz) to 3.90 (Sample B at 5000 Hz).

scholarly journals Acoustic Panels Made of Paper Sludge and Clay Composites

2021 ◽  
Vol 13 (2) ◽  
pp. 637
Author(s):  
Tomas Astrauskas ◽  
Tomas Januševičius ◽  
Raimondas Grubliauskas
Keyword(s):  
Absorption Coefficient ◽  
Sound Absorption ◽  
Composite Panel ◽  
Sound Absorption Coefficient ◽  
Core Material ◽  
Paper Sludge ◽  
Frequency Range ◽  
Absorption Properties ◽  
Air Gaps ◽  
The Core

Studies on recycled materials emerged during recent years. This paper investigates samples’ sound absorption properties for panels fabricated of a mixture of paper sludge (PS) and clay mixture. PS was the core material. The sound absorption was measured. We also consider the influence of an air gap between panels and rigid backing. Different air gaps (50, 100, 150, 200 mm) simulate existing acoustic panel systems. Finally, the PS and clay composite panel sound absorption coefficients are compared to those for a typical commercial absorptive ceiling panel. The average sound absorption coefficient of PS-clay composite panels (αavg. in the frequency range from 250 to 1600 Hz) was up to 0.55. The resulting average sound absorption coefficient of panels made of recycled (but unfinished) materials is even somewhat higher than for the finished commercial (finished) acoustic panel (αavg. = 0.51).

Adsorption of endocrine disrupting ethylparaben from aqueous solution by chemically activated biochar developed from oil palm fibre

2018 ◽  
Vol 54 (5) ◽  
pp. 683-695 ◽  
Author(s):  
Xiaohui Zhou ◽  
Jianjun Zhou ◽  
Yaochi Liu ◽  
Yang He ◽  
Jialin Ren ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Oil Palm ◽  
Activated Biochar ◽  
Endocrine Disrupting ◽  
Oil Palm Fibre ◽  
Palm Fibre

Study The Properties Of Mixed Kenaf And Empty Fruit Bunch (EFB) Oil Palm Fibre Insulation Paper

2021 ◽  
Author(s):  
Ja'afar Bin Adnan ◽  
Mohd Taufiq Bin Ishak ◽  
Nurul lIzzati Binti Hashim ◽  
Fakroul Redzuan Bin Hashim ◽  
Rushdan Bin Ibrahim ◽  
...  
Keyword(s):  
Oil Palm ◽  
Empty Fruit Bunch ◽  
Oil Palm Fibre ◽  
Palm Fibre

Utilization of Styrofoam ss Soundproofing Material with Auditory Frequency Range

2018 ◽  
Vol 13 (2) ◽  
Author(s):  
Sjahrul Meizar Nasri ◽  
Iting Shofwati
Keyword(s):  
Hearing Loss ◽  
Absorption Coefficient ◽  
Sound Absorption ◽  
Noise Exposure ◽  
Preventive Action ◽  
Frequency Range ◽  
Acoustical Property ◽  
Noise Barrier ◽  
Polystyrene Waste ◽  
Action Methods

One of preventive action methods of hearing loss that number tend to increase is by using brick that made from Styrofoam which is expected to have the ability as a soundproof that can be used to control the noise. The aim of this research is to assess the use of sound absorption material in which utilizing Styrofoam to reduce the noise exposure. In this study, cement and find aggregate that contain the Styrofoam and sand are mixed with the composition 1:4 and 1:6 and also by adding the polystyrene waste as much as 0%, 20%, 40%, 60%, and 80%.  To determine the acoustical property of the mixture, the sound absorbing coefficient (α) was determined by using Four Microphones Impedance Tube (ISO 140-3). The results showed that the highest absorption coefficient value was at frequency 800 Hz by adding 80% Styrofoam for the composition of 1:4 at 0.4100 dB and at the frequency 800 Hz by adding 40% Styrofoam for the composition 1:6 at 0.5870 dB. Based on the results of this research, further study to potentially use Styrofoam as noise barrier is suggested.

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