| 主权项 |
1. A multi-layer acoustical panel having improved sound absorption properties including a fiberglass layer and a mineral wool layer;
said fiberglass layer having a fibrous content comprising at least about 50% by weight of glass fiber and an associated binder providing structural rigidity and a density of from about 1 lb/ft3 to about 20 lbs/ft3; said mineral wool layer having a fibrous content comprising at least about 50% by weight of mineral wool fiber and an associated binder providing structural rigidity and a density of from about 8 lbs/ft3 to about 20 lbs/ft3; said mineral wool layer being more dense than said fiberglass layer, said panel having a total thickness that is substantially provided by said fiberglass layer and mineral wool layer; and said fiberglass and mineral wool layers being joined together by laminating, needling, adhesion or a combination thereof and having a structural rigidity making the panel self-supporting; said panel having a noise reduction coefficient value of at least about 0.55; wherein the panel noise reduction coefficient value linearly increases in response to increases in the thickness of the fiberglass layer; and wherein the panel is a ceiling tile, the mineral wool layer thickness is about ⅝″ and the fiberglass layer thickness is in the range of from about ¾″ to about 1″, the fiberglass layer is an air-laid fiberglass surface layer and the mineral wool layer is a water-felted mineral wool base layer, and the fiberglass layer includes glass fibers having a diameter in the range of from about 3 microns to about 15 microns and lengths in the range of from about 5 mm to about 15 mm. |
