| 摘要 |
PROBLEM TO BE SOLVED: To provide an acoustic material for automobiles having a high sound absorbing property in middle and high tone ranges, such as hitting sounds on the under surface of a fender section and the noise in an engine room. SOLUTION: The acoustic material consists of a felt material formed by integrating fibers alone or a plurality of the fibers after blending by needle punching and flame-retardant resin layers formed by coating on both surfaces of the felt material and the layers of the fibers alone remain in the middle of the felt material, by which the high sound absorbing property in the middle and high tone ranges is imparted to the acoustic material. Also, the acoustic material consists of the felt material formed by blending at least two kinds of the fibers varying in Young's modulus, then integrating the fibers by needle punching and the flame-retardant resin layers formed by coating on one surface of the felt material and the layers of the fibers alone remain on the opposite surface of the resin layers, by which the high sound absorbing property in the middle and high tone ranges may be imparted to the acoustic material. COPYRIGHT: (C)2003,JPO
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