The Structure Design And The Sound-absorbing Property Characterization Of The Multilayer Flexible Composite Materials

With the rapid development of economy, noise becomes more and more serious, andhas influenced people’s life. Therefore, in order to decrease the influence of environmentalnoise on people’s normal life, it is necessary to apply and develop sound-absorbing materialreasonably application and comprehensively improve the noise performance of the material.This paper mainly studies the relation between the sound-absorbing property and the internalstructure of polyester fabrics and non-woven materials. Traditional test methods have thereverberation chamber and the Impedance tube, and this paper developed a set of testinginstrument device for textile materials.Testing before and after the aluminum plating in thedifferent organizational structures of single, double, three and four layers polyester weavingfabrics using the device. After composite aluminum coating, the single plain weave, singlesatin weave and single honeycomb weave have a better noise. When fabrics compositealuminum coating, the noise reduction property has obvious increase. Single fabrics,soundabsorption property is quite limit, and cannot satisfy people. In order to increase the noisereduction performance of fabrics comprehensively, this paper composites a porousnonwoven material and fabric, and improve the sound-absorbing property of fabrics. Then,the topic applies the impedance tube to study the sound absorption property of compositematerials. The sound-absorbing property of the composite materials is higher than that alone,especially, in the low frequency area the sound-absorbing property of the compositematerials has obvious increase. With the increase of frequency, the sound-absorbingcoefficient increase, but, the sound-absorbing coefficient has a trend to down when itincreases to a certain degree, and at the low frequency area the sound absorption property ofthe sound-absorbing composite materials is weak, at the high frequency area the sound-absorbing composite materials is strong, and it is closely related to the internalstructure of the fabrics. Finally, the paper has a representation for the internal structure ofnonwoven by the theory of fractal. The experimental data show that the internal structure ofnonwoven assembly has fractal characteristic. Through the data analysis between the fractalstructure of nonwoven materials and its average ventilate rate and the average soundabsorption coefficient, the results show that nonwoven materials fractal dimensions has aclosely relation with average permeability rate and the average sound absorption coefficient.The greater the fractal dimensions, the better the ventilate property. When the fractaldimension becomes great, the sound absorption property of nonwoven gets improve.