scholarly journals Acoustic Properties of Mixing Empty Fruit Bunch and Oil Palm Frond Natural Fibres

2019 ◽  
Vol 8 (4) ◽  
pp. 6347-6349

Natural fibre is being studied and used as sound absorber for its promising acoustic properties. For instance, Germany have commercial plants that are producing sound absorbers from natural fibre. Natural fibre is eco-friendly and has no effect on human health. Besides that, the production cost of natural fibre is cheaper than synthetic fibre. This research reported the thickness effects on acoustic properties in different ratios of natural fibres of empty fruit bunch (EFB) and oil palm frond (OPF). Four different thickness of low density fibre board (LDF) have been fabricated (12 mm, 14 mm, 16 mm and 18 mm) in density of 120 kg/m3 . The Sound Absorption Coefficient (SAC) was tested by using the Impedance Tube Method (ITM) according to ASTM E1050-98 standards at frequency from 0 Hz to 6400 Hz. The results show the values of SAC for all samples increase with increasing in thickness from frequency range of 0 Hz – 4500 Hz. It is noteworthy that the LDF with thickness of 16 mm and 18 mm can be classified as Class A sound absorbing material according to sound absorption classes and possess the SAC values of 0.8 and above at a wider frequency range, which is 2500 Hz to 6400 Hz. The combination of EFP and OPF natural fibres has a very promising and excellent performance in acoustic properties.

2021 ◽  
Vol 317 ◽  
pp. 361-368
Author(s):  
Mageswaran Ravi Chandran ◽  
Ewe Lay Sheng ◽  
Yew Weng Kean ◽  
Mohammad Nazhan Nasir ◽  
Zawawi Ibrahim

The expansion of the oil palm industry has affected the environment and the poor handling of oil palm waste has greatly endangered the habitat surrounds it. The oil palm natural fibre waste can be put to good use and used as a sound absorber for its amazing acoustic properties. At the same time, the demand for natural fibre sound-absorbing panels is increasing due to its low-cost fabrication and its healthier than synthetic fibre. This research has studied the acoustic properties of mixing Empty Fruit Bunch (EFB) and Oil Palm Frond (OPF) in a thickness of 12 mm, 14 mm, 16 mm, and 18 mm. The fibreboard has been fabricated at a density of 120 kg/m3. The Sound Absorption Coefficient, SAC, and morphologies of all the samples were examined using the Impedance Tube Method (ITM) and Scanning Electron Microscope, (SEM). The sample’s SAC value increased with thickness. It is noteworthy that this combination percentage of natural fibres of EFB and OPF show good acoustic performance where the SAC values above 0.8 at wide frequency 3000 - 6400 Hz. Sample thickness 14 mm, 18 mm achieved unity (1.0) at frequency 4000 - 5500 Hz. In addition, all the samples were found to exceed 90 % of the absorption rate in the range of 4500 - 6400 Hz. The morphology content of EFB and OPF helps in enhancing the absorption rate.


2021 ◽  
Vol 1078 (1) ◽  
pp. 012005
Author(s):  
L S Ewe ◽  
Mohammad Nazhan Nasir ◽  
W K Yew ◽  
R Mageswaran ◽  
Zawawi Ibrahim

2018 ◽  
Vol 9 (3S) ◽  
pp. 335
Author(s):  
E. Baharudin ◽  
A. Ismail ◽  
A.R.H. Alhawari ◽  
E.S. Zainudin ◽  
D.L.A.A. Majid ◽  
...  

Author(s):  
M. Rusli ◽  
R.S. Nanda ◽  
H. Dahlan ◽  
M. Bur ◽  
M. Okuma

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.


2019 ◽  
Vol 52 (3) ◽  
pp. 1223-1228
Author(s):  
Hao Wu ◽  
Zhenming Zhou ◽  
Yuanlong Yang ◽  
Qingxiang Meng

Abstract In this study, we evaluated the effect of steam explosion of oil palm frond (OPF) and oil palm empty fruit bunch (EFB) on nutrient composition and ruminal fermentation characteristics in vitro. The results showed that steam explosion decreased NDF (P < 0.01), ADF (P < 0.01), and hemicellulose content (P < 0.01) in OPF and EFB. Steam explosion improved the effective energy value of OPF and EFB. In vitro fermentation results revealed that 72-h gas production capacity of OPF and EFB increased by 12.60and 85.06% (P < 0.01), respectively, after steam explosion. Steam explosion had a tendency to improve the concentration of total volatile fatty acids (TVFA) (P = 0.082). In conclusion, steam explosion of OPF and EFB reduced NDF, ADF, and hemicellulose content and increased gas production and TVFA concentration.


2021 ◽  
pp. 103282
Author(s):  
Mohammed Abobakr Al-Maari ◽  
Mohd Azmier Ahmad ◽  
Azam Taufik Mohd Din ◽  
Hamizura Hassan ◽  
Ahmed Mubarak Alsobaai

2021 ◽  
Vol 78 (1) ◽  
pp. 11-17
Author(s):  
Mohammad Nazhan Nasir ◽  
Ewe Lay Sheng ◽  
Yew Weng Kean ◽  
Woon Hai Song ◽  
Zawawi Ibrahim

Noise is defined as an unpleasant or loud sound, which may cause disturbance to others. It can damage an inner ear and even cause noise-induced hearing loss, threatening health and well-being. Researchers have successfully studied and invented many different types, shapes, and sizes of sound absorbers to absorb/control unwanted noises. A simple method used to control noise is by controlling the noise source using acoustic absorption panels, reducing noise along the transmission path, and protecting the noise at the receiving end before it reaches the receiver. Presently, the market or in most developed countries uses synthetic materials for buildings to absorb sound. The commonly used synthetic materials are glass or mineral fibers as they can be produced chemically in the factory very quickly. However, materials such as foam, rock wool, and glass wool made from minerals are recognized for their poisonous and polluting effects, which are harmful to human health and the environment. This paper reported the effect of substitution of Jute on the acoustic performance of Oil Palm Frond (OPF) natural fibers (150 kg/m3) with a thickness of 19 mm. Jute is suitable for insulating, antistatic, and low thermal conductivity. It also has a promising result of sound absorption coefficient (SAC) at lower frequency range (50 - 1000 Hz), and on the contrary for OPF, the SAC is only promising at higher frequency range (2000 Hz - 6400 Hz). Thus, it will be very remarkable to study these two blending fibers' acoustic performance. The findings show the substitution of Jute to broaden the frequency range of SAC above 0.8. For 20 % of jute substitution, SAC's frequency range above 0.8 is 1600 – 6400 Hz. Whereas for both 40 % and 60 % of jute substitution, the frequency range is marginally widened to 1400 – 6400 Hz. For 80 % of jute substitution, the frequency range of SAC above 0.8 has been increased to 1000 – 6400 Hz. An impressive result has been observed, where 100 % OPF unable to reach the SAC of 0.9 throughout the frequency range of 0 – 6400 Hz. Jute has proved its ability to improve its acoustic performance at a more comprehensive frequency range.


Author(s):  
F S Hashim ◽  
H W Yussof ◽  
M A K M Zahari ◽  
R A Rahman ◽  
R M Illias

2014 ◽  
Vol 893 ◽  
pp. 488-491 ◽  
Author(s):  
Elfarizanis Baharudin ◽  
Alyani Ismail ◽  
Adam Reda Hasan Alhawari ◽  
Edi Syams Zainudin ◽  
Dayang L.A. Majid ◽  
...  

This paper presents the results on dielectric properties of pulverized material based on agricultural waste namely oil palm frond and pineapple leaf fiber for microwave absorber application in the X-band frequency range. The investigation is started by identifying the pulverized materials permittivities and loss tangents using coaxial probe technique, followed by density measurement comprising the determination of bulk and solid densities. Then, by using dielectric mixture model, the solid particle dielectric properties were determined. It is observed that the air properties give quite an effect on the permittivity and loss tangent of the pulverized materials. It is also found that the lower the material density the higher material dielectric constant will be. Furthermore, the results show that, both oil palm frond and pineapple leaf fiber are potential to be X-band absorber with average dielectric constant of 4.40 and 3.38 respectively. The loss tangents for both materials were observed to be more than 0.1 which mark them as lossy materials.


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