Now showing 1 - 2 of 2
  • Publication
    Sound absorption coefficient measurement and analysis of bio-composite micro perforated panel (BC-MPP)
    (Springer, 2023) ;
    Lee Jia Jian
    ;
    ;
    Siti Hajar Ishak
    The sound absorption performance of bio-composite micro-perforated panel (BC-MPP) made from composite polypropylene (PP) filled rice husk (PP/RH), and coconut coir (PP/CC) is presented. The sound absorption coefficient (SAC) of BC-MPP was obtained via the impedance tube two-microphone method, and the investigation was according to types of fillers, filler compositions, perforation ratio, and the air gap size. It was found that the SAC of BC-MPP PP/RH provides a higher SAC value than BC-MPP PP/CC. Furthermore, the SAC peak was observed to shift to the lower frequency spectrum when there was an increment in filler content, the distance between the perforation, and the air gap size. The SAC value from the simulation also shows a good agreement with the experimental result.
      15  2
  • Publication
    Sound absorption coefficient measurement and analysis for multisection perforation microperforated panel
    ( 2024-01-01) ; ; ;
    Chan C.K.
    ;
    Teoh R.J.
    The microperforated panel (MPP) is a resonant-type sound-absorbing material considered the next-generation sound-absorption material due to its attractive characteristics. However, the drawback of narrow bandwidth sound absorption remains a matter of concern. This study explored the impact of varying backing cavity depths and different combinations of multi-section perforation sizes on the sound absorption performance of microperforated panels (MPP). A two-microphone impedance tube was used to obtain the sound absorption coefficient (SAC) of MPP following the ISO 10534-2 standard. MPP with single-size perforation diameters of 0.5, 0.7, and 1.0 mm which were compared to multi-section MPP with combinations perforation sizes of 0.5 & 0.7, 0.7 & 1.0, and 0.5 & 1.0 mm. The investigation reveals that increasing the backing cavity depth from 1.0 cm to 3.0 cm generally shifts the sound absorption coefficient (SAC) peak to a lower frequency range and decreases the SAC peak across all MPP samples. A higher SAC peak and wider absorption bandwidth were achieved from 0.5 mm single-size perforation diameter MPP and its combination in multi-section perforation MPP.