| 摘要 |
1,049,419. Wall or ceiling linings. SULZER BROTHERS Ltd. Oct. 5, 1964 [Nov. 21, 1963], No. 40514/64. Heading E1V. [Also in Division G5] A sound-absorbing wall or ceiling lining comprises a perforated tray or sheet 1 of metal, plaster fibre board or plastics spaced outwardly from an inner polyethylene sheath or sheaths 3 containing mineral wool by an intermediate layer 7 of open-pored foamed plastics material. The perforations 9 may be regularly or irregularly spaced, and the sheaths are arranged to be a distance away from the tray or sheet not less than the radius or the near radius of the perforations. |
