Glass wool is a kind of insulation material with excellent characters. It is made of natural ores such as quartz sand, dolomite, feldspar, limestone and so on, which are melted into glass fluid by adding in accessories such as calcined soda and borax and then drawn, blown or thrown into very thin fibers by external force under fusing state. As a kind of inorganic fiber, glass wool has the following basic characteristics: 1. Possessing good thermal insulation performance under both high and low temperature. 2. Neither burns, nor gives off harmful gas, so it is recognized as "statutory incombustible material" by many countries. 3. Possessing uniform resilience force. 4. Possessing sound-absorption performance from intermediate/ low frequency to high frequency and excellent noise reducing effect. 5. With low moisture absorption rate under humid conditions. 6. With low coefficient of linear expansion. 7. With low aging rate, being able to maintain the original performance after long-time use. 8. Possessing excellent handling characteristics.