纤维形态对针刺非织造布吸声系数的影响

利用驻波管测试方法研究了几种不同截面异形度、不同细度与直径、不同周长比与比表面积,以及不同体积分数与空隙率纤维材料的吸声性能。实验结果表明,纤维异形截面在一定程度上影响材料吸声性能,而吸声系数受纤维异形度的影响较复杂,即异形度不是吸声系数的本质影响因素。纤维比表面积参数是影响吸声性能的本质因素,比表面积越大,气-固相声阻越大,而纤维细度即纤维平均直径与其比表面积成反比,故直径越大,吸声系数越小。纤维体积分数是影响吸声性能的又一本质因素,空隙率越小,体积分数越大,即孔洞越小,空隙率越小,吸声系数越大。

Effect of fiber morphology on the sound absorption coefficient of needle-punched nonwovens

The standing wave tube is used to test the sound absorption properties of several fibrous materials with different shape factors of cross-section, different fineness and diameters, different perimeter ratios and specific surface areas, different fiber volume fractions and porosities. The results show that the shape factor of cross-section influences the sound absorption property of the needle-punched nonwoven to some extent, however the influence is rather complex, and the shape factor of cross-section is not an essential factor of influencing the sound absorption coefficient. Specific surface area of the fibers is the essential factor affecting absorption property: the larger the specific surface area, the greater the gas-solid phase acoustic resistance. The fiber fineness (dtex) is inversely proportional to the specific surface area, so the larger the diameter, the smaller the sound absorption coefficient. The fiber volume fraction is another important factor: the smaller the porosity, the greater the volume fraction, i.e. the smaller the holes, the smaller the porosity, therefore the greater the sound absorption coefficient.