Glass wool belongs to a category of glass fiber, is a kind of artificial inorganic fiber. Using quartz sand, limestone, dolomite and other natural ores as the main raw materials, combined with some soda ash, borax and other chemical raw materials to melt glass. In the melting state, with the help of external force blowing, flocculent fine fibers are spun. The fibers intersect and intertwine with each other, showing many small gaps. This gap can be regarded as a pore. Therefore, glass wool can be regarded as a porous material with good thermal insulation and sound absorption properties.

　　The thickness of glass wool is constant, the bulk density increases, and the absorption coefficient of medium and low frequency increases; However, when the bulk density increases to a certain extent, the material becomes dense, the flow resistance is greater than the best flow resistance, and the sound absorption coefficient decreases. For the centrifugal glass wool with a bulk density of 16KG / m3 and a thickness of more than 5cm, the sound absorption coefficient of 125Hz at low frequency is about 0.2, and the sound absorption coefficient at medium and high frequency （> 500Hz） is close to 1.

　　When the thickness of glass wool increases from 5cm, the sound absorption coefficient of low frequency increases gradually. When the thickness is more than 1m, the sound absorption coefficient of low frequency 125Hz will also be close to 1. When the thickness is constant and the bulk density is increased, the low-frequency sound absorption coefficient of centrifugal glass wool will continue to increase. When the bulk density is close to 110kg / m3, the sound absorption performance reaches a high value, which is close to 0.6-0.7 at the thickness of 50mm and the frequency of 125Hz. When the unit weight is more than 120kg/m3, the sound absorption performance will decrease, because the material becomes dense and the sound absorption performance of medium and high frequency is greatly affected. When the unit weight exceeds 300kg/m3, the sound absorption performance will be reduced a lot. The thickness of acoustic glass wool commonly used in architectural acoustics is 2.5cm, 5cm and 10cm, and the unit weight is 16, 24, 32, 48, 80, 96, 112kg/m3. Centrifugal glass wool with 5cm thick, 12-48kg/m3 is usually used.