The main material difference between 4oz fiberglass clothand glass is due to the difference in formulation due to different material requirements during manufacture. The silicon dioxide content of flat glass is about 70-75%, while the silicon dioxide content of glass fiber is generally less than 60%.

Glass is an inorganic material that has been melted at high temperatures (above 800C, as opposed to 1,100 C for everyday glass) and does not chemical reaction below the softening point. Above the softening point temperature, only softening, melting or decomposition, there will be no combustion phenomenon.

4oz fiberglass cloth is made by drawing the glass into very thin glass fibers, which are then very flexible. A 4oz fiberglass cloth can be made by spinning glass into yarn and then weaving it on a loom. Because the glass wire is extremely fine, the unit mass of the surface area is very large, so the temperature resistance performance has declined. Just as a candle can melt the fine copper wire.

But glass does not burn. The burning that we can see is actually to improve the performance of 4oz fiberglass cloth while coating the surface of 4oz fiberglass cloth with a resin material, or an attached impurity. Pure 4oz fiberglass cloth or coated with some heat-resistant paint can be used to make products such as fire-resistant clothing, fire-resistant gloves, and fire-resistant blankets. But if direct contact with the skin, the broken fibers on the skin the greater irritation, it will be very itchy.