<p class="MsoNormal" style="text-align:justify;text-indent:13.5pt;"><span style="font-size:10pt;" lang="in" xml:lang="in">The use of modern devices and human activity today have increased noise problem. The applicaton of </span><span style="font-size:10pt;">acoustic panels </span><span style="font-size:10pt;" lang="in" xml:lang="in">in building construction could be as an alternative </span><span style="font-size:10pt;">to overcome this problem. The purpose of this study was to investigate </span><span style="font-size:10pt;" lang="in" xml:lang="in">acoustical properties of </span><span style="font-size:10pt;">sound absorption coefficient and sound transmission loss </span><span style="font-size:10pt;" lang="in" xml:lang="in">from </span><span style="font-size:10pt;">wood wool</span><span style="font-size:10pt;" lang="in" xml:lang="in"> or </span><span style="font-size:10pt;">excelsior board. </span><span style="font-size:10pt;" lang="in" xml:lang="in">Three</span><span style="font-size:10pt;"> fast growing species</span><span style="font-size:10pt;" lang="in" xml:lang="in">, </span><span style="font-size:10pt;">sengon (<em>Paraserianthes falcataria</em>), african wood (<em>Maesopsis eminii</em>), and mangium (<em>Acacia mangium</em>)</span><span style="font-size:10pt;" lang="in" xml:lang="in"> lumbers were processed to obtain wool particles. Two different categories of board density and types of resins were used in this study. </span><span style="font-size:10pt;">Sound absorption coefficient was determined using the impedance tube method, while that for the determination of transmission loss based on the reverberation room method. The results showed that the board density of 0.8 g/cm³ had good sound absorption for low and high frequenc</span><span style="font-size:10pt;" lang="in" xml:lang="in">ies</span><span style="font-size:10pt;"> compared with board of 1.0 g/cm³.</span><span style="font-size:10pt;" lang="in" xml:lang="in"> In the medium frequencies those boards reflected the sound.</span><span style="font-size:10pt;" lang="in" xml:lang="in"> </span><span style="font-size:10pt;" lang="in" xml:lang="in">Wood wool </span><span style="font-size:10pt;">cement bonded board was good in sound absorption for high frequency. </span><span style="font-size:10pt;" lang="in" xml:lang="in">In the </span><span style="font-size:10pt;">range low to high frequenc</span><span style="font-size:10pt;" lang="in" xml:lang="in">ies</span><span style="font-size:10pt;">, the boards with isocyanate adhesive were good in transmission loss value</span><span style="font-size:10pt;" lang="in" xml:lang="in"> compared with cement bonded boards</span><span style="font-size:10pt;">.</span><span style="font-size:10pt;" lang="in" xml:lang="in"> Meanwhile, the boards with density of 1.0 g/cm³ possessed transmission loss value higher than board of 0.8 g/cm³.</span></p> <p class="MsoNormal" style="text-align:justify;"><span style="font-size:10pt;" lang="in" xml:lang="in"> </span></p> <p class="MsoNormal" style="margin-left:49.65pt;text-align:justify;text-indent:-49.65pt;"><em><span style="font-size:10pt;">Keywords:</span></em><em><span style="font-size:10pt;" lang="in" xml:lang="in"><span> </span></span></em><em><span style="font-size:10pt;">acoustic panel, wood wool</span></em><em><span style="font-size:10pt;"> </span></em><em><span style="font-size:10pt;">board, fast growing species, sound absorption, transmission loss</span></em></p>

Abstract

The use of modern devices and human activity today have increased noise problem. The applicaton of acoustic panels in building construction could be as an alternative to overcome this problem. The purpose of this study was to investigate acoustical properties of sound absorption coefficient and sound transmission loss from wood wool or excelsior board. Three fast growing species, sengon (Paraserianthes falcataria), african wood (Maesopsis eminii), and mangium (Acacia mangium) lumbers were processed to obtain wool particles. Two different categories of board density and types of resins were used in this study. Sound absorption coefficient was determined using the impedance tube method, while that for the determination of transmission loss based on the reverberation room method. The results showed that the board density of 0.8 g/cm³ had good sound absorption for low and high frequencies compared with board of 1.0 g/cm³. In the medium frequencies those boards reflected the sound. Wood wool cement bonded board was good in sound absorption for high frequency. In the range low to high frequencies, the boards with isocyanate adhesive were good in transmission loss value compared with cement bonded boards. Meanwhile, the boards with density of 1.0 g/cm³ possessed transmission loss value higher than board of 0.8 g/cm³.

Keywords:     acoustic panel, wood wool board, fast growing species, sound absorption, transmission loss