杨絮纤维/EVA吸声复合材料的制备及吸声性能

Fabrication and sound absorption properties of populus tomentosa fiber/EVA sound absorption composite materials

为解决废弃杨絮纤维引起的环境污染问题,以杨絮纤维为增强材料、EVA为基体材料,通过热压法制备杨絮纤维/EVA吸声复合材料。通过单因素试验,以传递函数法测得的平均吸声系数和降噪系数为检测指标,并兼顾材料成型效果,确定杨絮纤维/EVA吸声复合材料的最佳工艺参数,即热压温度为105℃、热压时间为20 min、杨絮纤维质量分数为45%。研究发现,当复合材料厚度为1.5 cm、复合材料密度为0.102 g/cm3、后空气层厚度为10.0 mm时,杨絮纤维/EVA吸声复合材料的平均吸声系数为0.41,降噪系数为0.40,最大吸声系数可达到0.65,吸声性能等级达到Ⅲ级。结合扫描电镜照片,以及不同工艺参数及设计参数下复合材料的吸声特性的分析,得出杨絮纤维/EVA吸声复合材料的吸声机理主要是多孔吸声机理。

In order to solve the problem of environmental pollution caused by waste populus tomentosa fibers,populus tomentosa fiber/EVA sound absorption composite materials were prepared by the hot pressing method with populus tomentosa fibers as reinforcing material and EVA as matrix material.Through single factor experiments,taking the average sound absorption coefficient and noise reduction coefficient measured by transfer function method as detection indexes,and considering the molding effect of material,the best process parameters were determined,which were the hot-pressing temperature was 105℃,the hot-pressing time was 20 min and the mass fraction of populus tomentosa fiber was 45%.Moreover,the study found that when the thickness was 1.5 cm,the density was 0.102 g/cm3,and the thickness of the back air layer was 10.0 mm,the average sound absorption coefficient of the populus tomentosa fiber/EVA sound absorption composite material was 0.41,the noise reduction coefficient was 0.40,the maximum sound absorption coefficient could reach 0.65,and the sound absorption grade reached grade III.Combining the scanning electron micrographs with the analysing of the sound absorption characteristics of the composite materials under different process parameters and design parameters,it was concluded that the sound absorption mechanism of the populus tomentosa fiber/EVA sound absorption composite material was mainly porous sound absorption mechanism.