Nonwoven sound-absorbing materials are versatile - China Garment Website_China's popular garment and fashion information platform

With the rapid development of industry, agriculture, transportation, etc., noise pollution has become increasingly serious, which not only harms human physical and mental health, but also accelerates the aging of buildings, machinery and equipment and other facilities. Today, when we advocate green, pollution-free, and high-quality life, new high-efficiency sound-absorbing materials have attracted widespread attention.

The way sound-absorbing materials filter sound is to convert sound energy into other forms such as heat energy, vibration energy, etc., and then dissipate the energy. According to the sound absorption mechanism, sound-absorbing materials are mainly divided into porous sound-absorbing materials and resonant sound-absorbing materials. Among them, porous sound-absorbing materials have better sound absorption effects in high frequency and broadband, and are currently the most widely used sound-absorbing materials. Nonwoven fiber materials are porous, light, soft, and low-cost. They are typical porous fibrous flexible materials and have been widely used in the field of sound absorption.

Sound absorption mechanism of porous sound-absorbing materials

When sound waves propagate in the medium, due to the different density and vibration amplitude of the vibrating particles, there will be speed and temperature gradient differences between the vibrating particles when the sound waves propagate, that is, there are different propagation speeds and energy losses in the medium. The interior of the porous sound-absorbing material has micro-channels that are interconnected on the outer surface. When sound waves are incident on the surface of the porous material, they will produce multiple reflections (or scattering), transmission, absorption and other phenomena like light. Sound waves can also cause the molecular chains of flexible materials and even larger structural units to vibrate, causing internal friction and heating in the material. That is, sound energy is converted into heat energy and vibration energy is dissipated or reflected on the surface of the material.

Characteristics of nonwoven porous sound-absorbing materials

Nonwoven porous sound-absorbing materials are made of fiber materials through non-woven processing technology. They are porous flexible materials with the advantages of high porosity, light weight, softness, etc. They are one of the most widely used porous sound-absorbing materials.

In terms of processing methods, nonwoven materials are materials directly reinforced by fibers. Their fiber raw materials come from a wide range of sources, and the type, length and fineness of the fibers are not restricted during processing. Compared with traditional textile processing, nonwoven material processing methods are complex and changeable. Different combinations of web forming and consolidation methods will process nonwoven porous materials with different structures and properties. For example, needle punched nonwoven materials are made of single fibers. It is made of raw materials and is reinforced by carding, netting and needle punching. It is characterized by high porosity, many and uniform pores, small pore size and layer-by-layer defense. It has a good absorption effect on sound waves. Nonwoven materials can also be post-processed by singeing, calendering, adding polymer sound-absorbing particles, etc. to increase the reflection and absorption capabilities of sound waves on the surface of the material, which is more beneficial to the sound absorption effect of the material.

Structurally speaking, nonwoven materials have a three-dimensional network porous structure, high porosity, and curved channels. This structure increases the multiple reflections and energy conversion of sound waves inside the nonwoven material, and causes the fiber material to vibrate. , so that the sound energy is lost to a large extent, thus meeting the performance requirements of porous sound-absorbing materials.

Types and applications of nonwoven porous sound-absorbing materials

With the continuous development of nonwoven technology and the successful research and development of new fiber materials, various fiber materials and processing techniques are being widely used in the development of sound-absorbing materials, and their products are also widely used in the field of sound absorption. At present, non-woven porous sound-absorbing materials with excellent performance are used in sound-absorbing and noise-reducing material projects such as theaters, auditoriums, broadcast rooms, automobiles, and space shuttles, etc. to reduce noise and vibration, etc., and improve people’s quality of life and work environment.

There are many types of non-woven porous sound-absorbing materials, and the classification methods are also different. According to the processing technology, they can be divided into needle-punched processing, spunlace processing, spunbond processing, composite processing, etc.; according to the fiber type, they can be divided into natural Fibers, metal fibers, chemical fibers, etc.; according to application fields, they can be divided into indoor and outdoor categories. Indoor categories include sound-absorbing wall panels, ceiling panels, automobiles, etc., and outdoor categories include highway soundproof walls and elevated light rails. Road barriers, cooling towers, etc.

Source: Textile Herald