Improved sound absorption performance of synthetic fiber materials for industrial noise reduction: a review

Sound absorption mechanism, material modification and structural design of various synthetic fiber materials for industrial noise reduction are reviewed in this paper for the problems of low sound absorption coefficient (SAC) and narrow frequency band of porous materials. Delany-Bazley model and Johnson-Champoux-Allard (JCA) model are widely used to predict the SAC, but they are slightly different. The air viscous effect plays an important role in Delany-Bazley model and its modified forms, while JCA model and its modified forms consider the effect of thermal conduction in addition to air viscosity. In addition, synthetic fiber materials such as polymers, metal fibers and inorganic fibers are widely used in noise reduction fields of various industries due to their unique acoustic and mechanical performance. Acoustic properties of polymers are usually improved by adding fillers, using perforated structures, gradient porous structures, and multilayer composite structures. And improving preparation method, increasing thickness of back cavity, combining different pore sizes, developing new composite materials, and adopting perforation technology can greatly promote the engineering application of metal fibers in extreme environments. Common methods to improve the sound absorption performance of inorganic fibers are to modify preparation method, increase thickness of materials and research composite materials.

Automated summary

This paper reviews the sound absorption mechanism, material modification, and structural design of various synthetic fiber materials for industrial noise reduction, focusing on the issues of low sound absorption coefficient (SAC) and narrow frequency band of porous materials. The Delany-Bazley model and Johnson-Champoux-Allard (JCA) model are commonly used to predict SAC, with slight differences between them. The air viscous effect is important in the Delany-Bazley model and its modifications, while the JCA model and its modifications also consider the effect of thermal conduction in addition to air viscosity. Synthetic fiber materials such as polymers, metal fibers, and inorganic fibers are widely used in noise reduction fields due to their unique acoustic and mechanical performance. Improving the acoustic properties of polymers can be achieved through the addition of fillers, the use of perforated structures, gradient porous structures, and multilayer composite structures. For metal fibers, enhancing engineering applications in extreme environments can be achieved by improving the preparation method, increasing the thickness of the back cavity, combining different pore sizes, developing new composite materials, and adopting perforation technology. Common methods to improve the sound absorption performance of inorganic fibers include modifying the preparation method, increasing material thickness, and researching composite materials.