Coconut Coir Fiber : An Innovative, Sustainable, and Decorative Material for Interior Soundproofing and Acoustic Design

Abstract

Golden Fiber Acoustics: This research investigates the viability of coconut coir fiber as an innovative, sustainable, and decorative material for interior soundproofing and acoustic design. Traditional commercial sound absorbers, such as glass or mineral fibers, are often non-biodegradable and may pose health risks, spurring a demand for sustainable alternatives like natural fiber composites. The study focused on brown coir fiber due to its high strength, superior abrasion resistance, and elevated lignin concentration (approximately 45%). Specimens were fabricated using a hot press technique with a composition of 75% fiber and 25% starch, resulting in composites with varying thicknesses (6 mm, 6.8 mm, and 7.5 mm). Scanning Electron Microscopy (SEM) confirmed good bonding and the presence of porosity — an essential feature for acoustic performance. Acoustic testing revealed a direct correlation between thickness and performance, with the 7.5 mm thick samples demonstrating the highest and most consistent sound absorption. Furthermore, the orientation significantly mattered: Arrangement 2 (Natural Fiber toward the sound source) consistently exhibited superior and more stable sound absorption than Arrangement 1, especially at higher frequencies. This improved performance is attributed to the coir fiber's more porous structure, which allows sound waves to pass through and dissipate energy as heat. The market is ready for a coir acoustic panel but is cautious. The recommended commercial strategy is Performance-First, Design-Second, Sustainability-Always, leveraging the material's certified Noise Reduction Efficiency, Aesthetic Design, and features like Humidity Regulation to justify a premium price point.

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