Noise Suppression from the Banana Tree Stem

The banana trees.

Do not waste banana pseudostem sheath. The pseudostem is formed by the tightly packed overlapping leaf sheaths (see morfology of banana tree in here).

In the hands of Maharani Dian Permanasari, this sheath this could be a silencer. This project is a master's thesis at the Product Design Department, Bandung Institute of Technology (Institut Teknologi Bandung/ITB) in 2009-2010.

Sheath of the banana tree has a main character as soundproofing material that is hollow or porous. The material is also flexible to set up, durable, and has a motifs pattern and interesting texture to product development. "The ultimate goal is to develop a small industrial materials crafters banana tree," she told Tempo on November 1, 2012.

She chose kepok banana because the sheath is wider and thicker. After pulling off one by one, amounting to 5-6 layers of pseudostem sheath, the thickness of the match and can be used in 3rd and 4th layers. The deepest parts of pseudostem sheath not used because it contains a lot of water.

Cross section of banana pseudostem sheath. (Picture from: http://www.promusa.org/)

To dry the sheath, Maharani who is now a lecturer in University of Surabaya, using tools such as oven-sized metal boxes are pretty laid television table on the porch. "Through a hole or a door is opened, the wind and drying heat flow around the entrance," she said.

Banana pseudostem sheath drying lasted two weeks will bring a new motif, the patterns such as leopard skin. The sheets were dried stem and then cut into pieces 2-3 centimeters wide and plaited. From the various types of webbing, however, a hexagon pattern is by far the most suitable.

Wicker acoustic tested by impedance tube method. As a result, not all types of noise could be muffled equally well. Based on the frequency, rate of absorption from webbing silencer with varnish or not, at low frequencies the results are almost the same. Sound frequencies tested were in the range of 100-4000 Hz.

From the test results it sounds, woven banana sheaths suitable for use in the living room, theater room, and muffle the sound reflections from the speakers. Maharani said, the research will still continue to be woven could dampen high frequency sound steady.

Then she sent her work result to the "Smart Materials for Design and Architecture" seminar, held by Design Zentrum Nordrhein Westfalen. Once selected, chosen for this innovation presented along with nine other speakers from different countries on July 3, 2012 at the Red Dot Design Museum, Germany. "For them, the pseudostem sheath of the banana tree is an exotic material. And many of those who do not know the shape of a banana tree," she said. Now Maharani is taking care the woven silencer patent. *** [ANWAR SISWADI | KORAN TEMPO 4049]

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