Glass wool is created inside of a rigid sort to insulate ducts and pipes. It is available in several measurements to fit round ducts. Purely natural sand and recycled glass are mixed and heated to one,450 °C (two,640 °F), to make glass. The fiberglass is generally made by a technique https://glass-wool-board48260.amoblog.com/5-easy-facts-about-glass-wool-insulation-described-56098489