The main raw materials for producing glass fiber are: quartz sand, alumina and pyrophyllite, limestone, dolomite, boric acid, soda ash, saltpeter, fluorite, etc. The production methods are roughly divided into two categories: one is to directly make molten glass into fibers; the other is to first make molten glass into glass balls or rods with a diameter of 20mm, and then heat and remelt them in various ways to make very fine fibers with a diameter of 3 to 80μm. The infinitely long fibers drawn by mechanical drawing through platinum alloy plates are called continuous glass fibers, commonly known as long fibers. Discontinuous fibers made by rollers or airflow are called fixed-length glass fibers, commonly known as short fibers. The fine, short, flocculent fibers made by centrifugal force or high-speed airflow are called glass wool. Glass fibers can be processed into various forms of products, such as yarn, roving, chopped strands, cloth, tape, felt, plate, tube, etc.