Material classification of glass fiber

According to the shape and length, glass fiber can be divided into continuous fiber, fixed length fiber and glass wool; According to glass composition, it can be divided into alkali free, chemical resistant, high alkali, medium alkali, high strength, high elastic modulus and alkali resistant (alkali resistant) glass fibers.
The main raw materials for the production of glass fiber are: quartz sand, alumina and pyrophyllite, limestone, dolomite, boric acid, soda ash, mirabilite, fluorite, etc. Production methods can be roughly divided into two categories: one is to directly make molten glass into fibers; One is to make the molten glass into a glass ball or rod with a diameter of 20mm, and then heat and remelt it in various ways to make it into a glass ball or rod with a diameter of 3-80 μ M of very fine fibers. The infinitely long fiber drawn by mechanical drawing method through platinum alloy plate is called continuous glass fiber, which is generally called long fiber. The discontinuous fiber made by roller or air flow is called fixed length glass fiber, or short fiber.
Glass fiber can be divided into different grades according to its composition, nature and use. According to the standard level, Class E glass fiber is the most widely used electrical insulating material; Class S is a special fiber.
E-glass
Also called alkali free glass, it is a borosilicate glass. At present, it is the most widely used glass fiber with glass composition, which has good electrical insulation and mechanical properties. It is widely used in the production of glass fiber for electrical insulation, and also widely used in the production of glass fiber for glass fiber reinforced plastics. Its disadvantage is that it is easy to be eroded by inorganic acid, so it is not suitable for use in acidic environments.
C-glass
Also called medium alkali glass, it is characterized by its chemical resistance, especially its acid resistance, is better than that of non alkali glass, but its electrical performance is poor, and its mechanical strength is 10%~20% lower than that of non alkali glass fiber. Generally, foreign medium alkali glass fiber contains a certain amount of boron trioxide, while domestic medium alkali glass fiber does not contain boron at all. In foreign countries, medium alkali fiberglass is only used to produce corrosion-resistant fiberglass products, such as fiberglass surface felt, and also used to strengthen asphalt roofing materials. However, in China, medium alkali fiberglass accounts for more than half (60%) of the output of fiberglass, and is widely used for the reinforcement of fiberglass and the production of filter fabrics, wrapping fabrics, etc. Because its price is lower than that of alkali free fiberglass, it has strong competitiveness.
High strength glass fiber
It is characterized by high strength and high modulus. Its tensile strength of single fiber is 2800MPa, about 25% higher than that of alkali free glass fiber, and its elastic modulus is 86000MPa, higher than that of E-glass fiber. The fiberglass products produced with them are mostly used in military industry, space, bulletproof armor and sports equipment. However, due to the high price, it can not be popularized in civilian use, and the world output is only about several thousand tons.
AR glass fiber
Also called alkali resistant glass fiber, alkali resistant glass fiber is the rib material of glass fiber reinforced (cement) concrete (GRC for short), is 100% inorganic fiber, and is an ideal substitute for steel and asbestos in non bearing cement components. Alkali resistant glass fiber is characterized by good alkali resistance, effective resistance to the erosion of high alkali substances in cement, strong grip, high elastic modulus, impact resistance, tensile strength, bending strength, strong incombustibility, frost resistance, temperature resistance, humidity change, excellent crack resistance and impermeability, strong designability, easy molding, etc, Alkali resistant glass fiber is a new type of green and environment-friendly reinforcement material widely used in high-performance reinforced (cement) concrete.
A Glass
Also called high alkali glass, it is a typical sodium silicate glass, which is rarely used to produce glass fiber because of its poor water resistance.
E-CR glass
It is an improved boron free and alkali free glass, which is used to produce glass fiber with good acid resistance and water resistance. Its water resistance is 7-8 times better than that of alkali free glass fiber, and its acid resistance is also much better than that of medium alkali glass fiber. It is a new variety specially developed for underground pipelines, storage tanks, etc.
D Glass
Also called low dielectric glass, it is used to produce low dielectric glass fiber with good dielectric strength.
In addition to the above glass fiber components, there is a new alkali free glass fiber, which is completely boron free, thus reducing environmental pollution, but its electrical insulation and mechanical properties are similar to the traditional E glass. In addition, there is a kind of glass fiber with double glass components, which has been used in the production of glass wool. It is said that it has potential to be used as FRP reinforcement. In addition, there is fluorine free glass fiber, which is an improved alkali free glass fiber developed for environmental requirements.
Identify high alkali glass fiber
The simple test method is to put the fiber in boiling water and boil it for 6-7h. If it is high alkali glass nitrate fiber, the warp and weft fibers will become loose after boiling. According to different standards, there are many classification methods for glass fibers, which are generally divided from the perspectives of length and diameter, composition and performance.