| 摘要 |
<p>Acoustic element (1) has a flat, sound-receiving, front face (2) which extends in the XY plane and has a good sound-absorption coefficient, and the element is formed of a bonded batt of air laid mineral fibres having a density of 70 to 200 kg/m3 wherein the fibres extend from the front face (2) and at least through the front half of the thickness of the batt have a Z direction component greater than the Z direction component of conventional air laid products, and the front face of the batt is a cut and abraded face. The element can be made by air laying mineral fibres and binder, reorienting the fibres to provide an increased fibre orientation in the Z direction, curing the binder to form a cured batt and cutting the cured batt in the XY plane into two cut batts and smoothing each cut surface by abrasion to produce a flat face on each cut batt.</p> |
