| 摘要 |
PROBLEM TO BE SOLVED: To provide a plaster molded sound absorber which has superior sound absorptivity and bending strength and with which fibrous dihydric plaster with superior flame retardancy is combined although the sound absorber is a molding of plaster as its principal material. SOLUTION: Plaster is heated and dissolved in hydrochloric acid and the hydrochloric acid solution in which the plaster is dissolved is cooled to precipitate the fibrous dihydric plaster for solid-liquid separation; and the remaining hydrochloric acid is washed away and then an organic adhesive is used to combine and mold the fibrous dihydric plaster, thus manufacturing the fibrous plaster molded sound absorber of void volume ratio 75 to 90% , sound absorbtion ratio≥10% at any frequency of a sound wave in a frequency range of 125 to 5,000 Hz, and bending strength≥0.3 MPa. COPYRIGHT: (C)2004,JPO
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