Influence of fineness, length and hollow section of fibers on acoustic absorption

Abstract

A fibrous material is characterized by its fineness, flexibility and high length/fineness ratio and it is used to reduce noise in indoor rooms due to their porous structure. The aim of this work is focused on investigating the structure of two different fibers (acrylic and polyester) from the analysis of the macrostructural parameters, such as fineness, length and cross-section (solid or hollow). Furthermore, the degree of influence of these parameters on the average sound absorption has been investigated. The sound absorption coefficient of fibers is measured at normal incidence in the impedance tube. In acrylic fibers, results showed that the fineness of the fiber has a significant influence on the sound absorption compared to the length of the fiber. In polyester fibers, hollow fibers have a better acoustic behavior compared to solid fibers.

Effect of acetylation modification on the structure and properties of windmill palm fiber

“…The decreased thickness shown in Figure 3(d) resulted in the decrease of acoustic properties, the same as reported in the literature. 32 What is more, the increase in the pore diameter, which can be seen in Figure 2, decreased the acoustic property. 33 The d 1 was about 4.1 times higher than d 2 for acetic anhydride-treated palm fibers.…”

Structural Characteristics and Sound Absorption Properties of Waste Hemp Fiber

“…The short length and poor neatness of the fallen hemp fibers make them less spinnable and more difficult to spin into high-count yarns. Since the fiber length did not have a significant effect on the soundabsorption properties of the material [40], it was suitable for the preparation of sound-absorbing materials, although the length of waste hemp fibers varied widely. Fiber fineness-The microscopic image of the waste hemp fiber was obtained by using an upright metallographic microscope.…”