Glass wool is one kind of the glass fiber and it is a man-made inorganic fiber. Glass is made by melting such raw materials as quartz sand, limestone, dolomite and other natural ore with some chemical materials like pure alkali and sodium borate. In the molten state, the glass is thrown into fine fibers in the shape of floc by the with external force. These fibres vertically interwine and show many small gaps. These gaps can be regarded as air void. Thus, glass wool can be regarded as porous materials and it is of good insulation and sound absorption performance.
Each insulation material has its own advantages and disadvantages. Let's take glass wool and rock wool as an example. Glass wool is less irritating to the workers' skin than than rock wool is in construction workers, but we can not say that the glass wool is not irritating at all. Besides, the melting point of glass wool and rock wool is different. The thermal insulation effect of glass wool is better than rock wool when they have the same bulk density and thickness.
