Glass fiber can be divided into continuous fiber, fixed length fiber and glass wool according to its shape and length. According to glass composition, it can be divided into alkali-free, chemical-resistant, high-alkali, medium-alkali, high-strength, high-elasticity and alkali-resistant ( Alkali resistant) glass fiber, etc.
The main raw materials for the production of glass fiber are: quartz sand, alumina and pyrophyllite, limestone, dolomite, boric acid, soda ash, thenardite, fluorite and the like. The production methods are roughly divided into two categories: one is to directly form the molten glass into fibers; the other is to first make the molten glass into a glass ball or rod with a diameter of 20 mm, and then remelt it in various ways to make a diameter of 3~ Very fine fiber of 80 μm. An infinitely long fiber drawn by a mechanical drawing method by a platinum alloy plate is called a continuous glass fiber and is generally called a long fiber. Non-continuous fibers made by rolls or air streams, called fixed length glass fibers, are commonly referred to as short fibers.
Glass fiber is divided into different grades according to composition, nature and use. According to the standard level (see table), E-grade glass fiber is most commonly used, widely used in electrical insulation materials; S grade is special fiber.