부산대학교 도서관

The effect of the sound on the human ear is mainly intermediate frequency and low frequency, ear hearing will grow with age and decline, older people are more sensitive to low-frequency sound, because the fiber and the surface lines for the sound effects have different effects, the study system combines nonwoven fabric with 3mm, 6mm, 9mm different diameter sandwich panels to measure the sound absorption effect, when the sandwich aperture is larger than the front of the sandwich plate aperture, In the 1000Hz frequency of the sound absorption rate of 0.80. When used in building sound insulation products, fire and strength detection Nonwovens sandwich plate after burning carbonization within 4cm, in the sandwich plate impact strength test, get the best size of 6mm / 3mm sandwich sheet impact strength of 18.9J.