| 摘要 |
PROBLEM TO BE SOLVED: To provide acoustical material capable exhibiting excellent sound absorption effect by increasing film vibration. SOLUTION: The acoustical material is constituted in such a manner that a resin film is joined to base material consisting of open cell foams in which the number of cells based on the Japanese Industrial Standard K6400 is 5 to 40 pieces/25mm width with an adhesive layer by adhesives, such as polyurethane system adhesives. It is desirable that the open cell foams are soft polyurethane foams. Moreover, it is desirable that cell films of the open cell foams are removed in order to raise a sound absorption property and a waste water discharging property and it is desirable that an air flow of the foams is 150 to 450 ml/cm<SP>2</SP>×sec. The acoustical material is constituted so that a sound absorption peak is located in low/middle frequency ranges being 200 to 2000Hz and it can exhibit sound absorption effect in the low/middle frequency ranges. COPYRIGHT: (C)2006,JPO&NCIPI
|
