The fiberglass manufacturing process starts by blowing molten glass through a rapidly rotating cylindrical drum containing numerous holes. The glass exits the drum in long, thin strands and is then sprayed with a binding agent and forcibly blown down into molds by heated air or inert gas. The finished fiberglass is either used as-is for loose fill insulation or glued to a paper backing for use as batt insulation.Continue Reading
The initial glass making step in the fiberglass production process is the same as for any other type of glass product. A mixture of clean sand, calcium carbonate, sodium carbonate and sometimes other minerals is heated in a furnace or oven to its melting point. While manufacturers of other glass products then pour the molten mixture into molds or pull it into sheets, fiberglass manufactures spin the glass into numerous small fibers or marbles.
Manufacturers produce different grades of fiberglass insulation using a variety of different methods. They can change the initial glass formula to produce insulation products of varying densities and, therefore, thermal efficiency. Manufacturers can also use spinning cylinders with larger or smaller holes to produce different sizes of glass threads. Finally, the strength of the air or gas that blows the molten threads into the molds affects how long the final glass threads are and how dense the insulation is.Learn more about Building Materials