Additive Manufacturing: A Novel Method for Developing an Acoustic Panel Made of Natural Fiber-Reinforced Composites with Enhanced Mechanical and Acoustical Properties

Table 11

Acoustical absorption coefficient of natural fibers.

Fibers	Fiber properties	Frequency (Hz)	Absorption coefficient (α)	References
Coir	Thickness, 35 mm	500	0.84	[70]
Oil palm	Thickness, 50 mm	1000	0.90	[88]
Flax	Diameter, 21.8 μm	500	0.40	[89]
Kenaf	Thickness, 50 mm	500	0.74	[70]
Jute	Diameter, 81.2 μm	500	0.20	[89]
Ramie	Thickness, 40 mm	800	0.60	[90]
Hemp	Thickness, 40 mm	500	0.60	[70]
Sisal	Diameter, 213 μm	500	0.10	[89]
Cotton	Diameter, 13.5 μm	500	0.50	[89]
Bagasse	Thickness, 20 mm	500	0.13	[91]
Corn	Thickness, 20 mm	500	0.16	[91]