Glass fibers can be classified by shape and length into continuous fibers, fixed-length fibers, and glass wool; and by glass composition into alkali-free, chemical-resistant, high-alkali, medium-alkali, high-strength, high-elastic modulus, and alkali-resistant (alkali-resistant) glass fibers, etc.
The main raw materials for producing glass fibers are: quartz sand, alumina and pyrophyllite, limestone, dolomite, boric acid, soda ash, mirabilite, fluorite, etc. Production methods are broadly divided into two categories: one is to directly produce fibers from molten glass; the other is to first form molten glass into glass spheres or rods with a diameter of 20mm, and then remelt them through various methods to produce very fine fibers with a diameter of 3-80μm. Infinitely long fibers drawn mechanically from platinum alloy plates are called continuous glass fibers, commonly known as long fibers. Discontinuous fibers produced by rollers or airflow are called fixed-length glass fibers, commonly known as short fibers.
Glass fibers are classified into different grades according to their composition, properties, and uses. According to standard specifications, Grade E glass fibers are the most commonly used and widely used in electrical insulation materials; Grade S is a special fiber. In addition to the glass fiber compositions mentioned above, a new type of alkali-free glass fiber has emerged. It is completely boron-free, thus reducing environmental pollution, while its electrical insulation and mechanical properties are similar to traditional E-glass. There is also a double-glass composition glass fiber already used in the production of glass wool, and it is said to have potential as a reinforcement material for fiberglass reinforced plastics. Furthermore, there is fluorine-free glass fiber, an improved alkali-free glass fiber developed to meet environmental protection requirements.
Identifying high-alkali glass fiber: A simple method of testing is to boil the fiber in boiling water for 6-7 hours. If it is high-alkali glass fiber, after boiling, both the warp and weft fibers will become loose. Glass fibers can be classified in many ways according to different standards, generally based on length and diameter, composition, and properties.