Acoustical Properties of Coconut Coir Fibers Used as Multilayered Materials

Interior lining components are generally made of various layers that combine plenty of different raw materials and technologies. Recently, concerns about sustainability and green technology have been focused on the automotive and aerospace industry. Nowadays, many vehicles are designed considering energy saving methods, alternative materials and the use of residues. The main aim of this paper is to investigate the acoustical properties of multilayered materials by testing traditional and “unusual” combinations. Combinations of coconut coir fiber and foam were considered on this study A few samples were assembled on layers and used as absorbers. Experimental tests were made in order to characterize the proposed materials in terms of their acoustical properties such as the absorption and acoustic impedance. Measurements were carried out using the impedance tube method. The results were compared with those obtained via a macroscopic empirical model namely the Delany-Bazley model [1].