Acoustical characteristic of empty fruit bunch (EFB) fibre with influence of sodium hydroxide treatment time and decay lifespan
Research on natural fibres has gain much interest in recent years due to the sustaibability and avaibility in which demand for green renewable reinforced composites. Natural fibres can be considered as the alternative way to replace the synthetic fibre as well as to implement the sustainability o...
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| Format: | Thesis |
| Language: | English English English |
| Published: |
2019
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| Subjects: | |
| Online Access: | http://eprints.uthm.edu.my/543/1/24p%20LAUREN%20MAT%20WAN.pdf http://eprints.uthm.edu.my/543/2/LAUREN%20MAT%20WAN%20COPYRIGHT%20DECLARATION.pdf http://eprints.uthm.edu.my/543/3/LAUREN%20MAT%20WAN%20WATERMARK.pdf |
| Summary: | Research on natural fibres has gain much interest in recent years due to the sustaibability
and avaibility in which demand for green renewable reinforced composites. Natural fibres
can be considered as the alternative way to replace the synthetic fibre as well as to
implement the sustainability of the materials. However, the natural fibre also has its own
disadvantage which is the ability to maintain the quality of absorption due to the lack of
information and research on the acoustic application. Thus, in this research, the untreated
and treated Empty Fruit Bunch (EFB) fibre was investigated as control unit and the
standard used for sound absorption test was ISO 10534-2 and ASTM E1050-98. The EFB
has undergone a chemical modification process known as alkali treatment using sodium
hydroxide (NaOH). Five parameters were chosen for the alkali treatment process which is
the fiber immersion time (at 1 hour until 5 hours) with fixed alkali treatment concentration
of 6% NaOH. Cross sectional area of the fibre was measured using Leica stereo video
analyser. The results from the test show EFB fibre gives positive value of sound
absorption from mid to high frequency which is from 2000 Hz to 5000 Hz. The best sound
absorption is performed by the 1 hour of treated fibre with a maximum sound absorption
coefficient (α) nearly 1 at 2500 Hz and with thickness of 50 mm. The Noise Reduction
Coefficient (NRC) for the 1 hour treated fibre is 0.53. As for decay lifespan, the sound
absorptions performance was slightly decreased from 0.68 to 0.55 within 5 to 20 months.
This result indicates that the treated EFB are highly absorptive material and it is
recommended to become as a natural base for acoustical absorption material. |
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