| 摘要 |
PROBLEM TO BE SOLVED: To improve a sound absorbing coefficient in a low frequency band even when thickness is thinned while handling properties as a material are enhanced by mutually bonding powder particles through binders and setting a Young's modulus at a specific value or less. SOLUTION: A sound absorbing material consisting of a molded form, in which powder particles 1 are bonded so that the mutual powder particles 1 can be vibrated at contact points 2 through binders 3 and molded and unified, is acquired. Since the sound absorbing material is formed in the unified molded form, handling properties are improved while the deterioration of sound absorbing characteristics due to the spill, deviation, etc., of powder is inhibited. Sound absorbing characteristics in a low frequency band are improved even when the thickness of the sound absorbing material is thinned by setting the Young's modulus of the sound absorbing material in 1.0×10<6> N/m<2> or less. It is desirable that mean grain size of 0.1-1000μm and bulk density within a range of 0.1-1.5g/cm<3> are acquired in powder composed of powder particles 1, and there is possibility that sound absorbing characteristics in a low sound zone are deteriorated when mean grain size or bulk density is deviated from these ranges.
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