孔形态对沙柳/HDPE复合碎料板吸声性能的影响

以沙柳和高密度聚乙烯（HDPE）为主要原料，通过沙柳碎料和高密度聚乙烯均匀混合的方式，采用热压工艺制备沙柳/HDPE复合碎料板，使用驻波管法研究背腔深度0~50 mm、钻孔深度0~18 mm、钻孔直径0~5 mm和孔排列形式（圆形、正方形、米字形和无规则）对沙柳/HDPE复合碎料板在低频区域200~2 000 Hz范围内声学性能的影响机制。结果表明:1)随背腔深度增加，沙柳/HDPE碎料板与空气层组成的板/腔结构平均吸声系数和降噪系数均呈增大变化趋势，最小吸声系数频率由400 Hz降至315 Hz，吸声系数趋于稳定频率向低频区域移动；2)随钻孔深度增加，沙柳/HDPE复合碎料板平均吸声系数和降噪系数呈增大变化趋势，最小吸声系数频率向低频区域移动，吸声系数趋于稳定频率向低频区域移动；3)复合碎料板平均吸声系数和降噪系数随直径增加而增大，最小吸声系数频率向低频区域移动；4)孔排列形式对平均吸声系数和降噪系数性能影响不明显，正方形排列综合声学性能优于米字形、无规则和圆形排列。通过改变孔形态或调整背腔深度，可提高沙柳/HDPE复合碎料板吸声性能和调整吸声频段。

Pore Morphology on Sound Absorption Properties of Salix/HDPE Particleboard

In this paper,Salix/HDPE particleboard was prepared by hot pressing uniformly mixed wood particles of Salix psammophila and high density polyethylene(HDPE).The acoustic properties of the composite in different back cavity depths(0-50 mm),hole depths(0-18 mm),hole diameters(0-5 mm)and hole arrangements(circular,square,meter and irregular)were characterized by using sound absorption coefficient(SAC)and noise reduction coefficient(NRC).The results indicated that:1)the average SAC and NRC of the plate/cavity structure increased with the depth of the back cavity,and the minimum SAC moved to the lower frequency region,the stabilized SAC moved to the low frequency region.2)The average SAC and NRC of the Salix/HDPE particleboard increased with the depth of the drilling,and the minimum and maximum SAC values moved to the lower frequency region.3)At the same drilling depth,the average SAC and NRC increased with the diameter of the holes.4)The arrangement of holes had little effect on the average SAC and NRC,and the sound absorption performance of the holes arranged in squares was slightly better than the holes arranged in meter arrangement,irregular arrangement and circular arrangement.By changing the hole shape or depth of back cavity,the sound absorption performance and frequency of Salix/HDPE particleboard could be improved.