Green Acoustic Absorber from Pineapple Leaf Fibers

The environmental issue becomes the central topic in the discussion for the last decade. Scientific works to overcome the problems are thus progressing including finding the alternative natural materials to replace the conventional synthetic ones. This chapter discusses the use of natural fibers extracted from pineapple leaf as natural acoustic absorber. The preparation for absorber samples is discussed, and the effects of fiber density, sample thickness, and introduction of backed air gap were measured using normal field incidence method in an impedance tube. The measured results reveal that the pineapple fibers can have good sound absorption above 500 Hz for thickness of 30 mm and density of 117 kg/m³. Almost the same performance can be achieved for thickness of 20 mm by introducing backed air gap of 20 mm. The effect of the quarter-wavelength with the presence of backed air gap can be clearly observed where this can be used as the design guide to determine the required thickness of the absorber.