Glass fiber (formerly known as glass fiber or fiberglass) is a kind of inorganic non-metallic material with excellent performance. It has many kinds. Its advantages are good insulation, strong heat resistance, good corrosion resistance and high mechanical strength, but its disadvantages are brittle and poor wear resistance. It is made of glass ball or waste glass by high-temperature melting, drawing, winding, weaving and other processes. The diameter of its monofilament is several microns to twenty microns, which is equivalent to 1 / 20-1 / 5 of a hair filament. Each bundle of fiber strands is composed of hundreds or even thousands of monofilaments. Glass fiber is usually used as reinforcement material, electrical insulation material, thermal insulation material, circuit board and other fields of national economy.