Glass wool is a kind of fibrous material made of natural ores such as quartzite, 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:

①Possessing good thermal insulation performance under both high and low temperatures.

② Neither burns, nor gives off harmful gas, so it is recognized as "statutory incombustible material” by many countries.

③Possessing uniform resilience force.

④Possessing sound-absorption performance from intermediate/low frequency to high frequency and excellent noise reducing effect.

⑤With low moisture absorption rate under humid conditions.

 ⑥With low coefficient of linear expansion.

⑦With low aging rate, being able to maintain the original performance after long-time use.

⑧Possessing excellent handling characteristics.

１．Main Materials in Centrifugal Blowing Technique for Glass Wool Production:

①Quartz sand: Its main composition is SiO2, content of which is above 90%.

②Feldspar: It can be classified into potash feldspar and albite according to its chemical composition. Chemical composition requirement for feldspar: Al2O3>15%, SiO2<70%, Fe2O3<0.3%, R2O>10%.

③Dolomite: Quality requirement for dolomite: MgO>20%, CaO<32%, Fe2O3<0.15. Dolomite is water-absorbent, so it should be stored in dry places.

④Calcined soda: Quality requirement for calcined soda: Na2CO3>98%, NaCl<1%,Na2SO4<0.1%,　Fe2O3<0.1%.

⑤Borax (Na2B4O7?10H2O): Quality requirement: B2O3>35%, Fe2O3<0.01%, SO42-<0.02%.

⑥Limestone: Quality requirement: CaO≥50%, Fe2O3≤0.15%.

⑦ Cullet: Broken and non-conforming glass products as well as glass chops made by chilling vitreous fluid in water, whether they are glass scraps produced in production or glass waste rejected in society, all can be used as raw materials for glass.

2．Centrifugal Glass Wool Production Process: Mixed batch is fused into vitreous fluid in kiln. There is a single-hole platinum leak boar d installed at forming part of the kiln, and well-fused vitreous fluid flows out from the leak board and forms a vitreous fluid stream, which will fall vertically into a centrifuge—the principal part of fiber forming equipment. The centrifuge rotates in high speed, and by making use of centrifugal force, it forces vitreous fluid to be thrown through pores on its surrounding wall to form primary fibers, which, still in high-temperature soft state, are immediately effected by air current jetted from ring-form combustion nozzles arranged concentrically with the centrifuge, and then further split and stretched into secondary fibers with average diameter 5～7μm, namely, glass wool. Glass wool felt and glass wool board are main products in which glass fibers are used as substrate material. While forming, glass wool fibers are covered with sprayed phenolic resin binder, and they fall downward to the conveyor of collector. Adjusting negative pressure of air draft at lower part of mesh belt can make the glass wool fibers uniformly spread into a batting layer on the mesh belt. Batting enters into solidifying furnace to go through drying, curing and shaping with felt board, and is cut vertically or horizontally as per required sizes into glass wool felt or board.