Glass fiber is an inorganic non-metallic material with excellent performance. It has many types. Its advantages are good insulation, strong heat resistance, good corrosion resistance, and high mechanical strength, but its disadvantages are brittleness and poor wear resistance. It is made of glass balls or waste glass through high-temperature melting, drawing, winding, weaving and other processes. The diameter of its single filament ranges from a few microns to more than 20 microns, which is equivalent to 1/20-1/5 of a hair. Each bundle of fiber strands is composed of hundreds or even thousands of single filaments. Glass fiber is usually used as a reinforcing material in composite materials, electrical insulation materials and thermal insulation materials, circuit substrates and other fields of the national economy.
Glass fiber composite material classificationAccording to the shape and length, glass fiber can be divided into continuous fiber, fixed length fiber and glass wool; according to the glass composition, it can be divided into alkali-free, chemical-resistant, high alkali, medium alkali, high strength, high elastic modulus and alkali-resistant glass fiber.
The main raw materials for producing glass fiber are: quartz sand, alumina and pyrophyllite, limestone, dolomite, boric acid, soda ash, mirabilite, fluorite, etc.
The production methods are roughly divided into two categories: one is to directly make fibers from molten glass; 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. 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.
Glass fibers are divided into different grades according to their composition, properties and uses. According to standard grade regulations, E-grade glass fibers are the most commonly used and widely used in electrical insulation materials; S-grade is special fiber.
There are many ways to classify glass fibers. Generally, they can be classified based on glass raw material composition, single fiber diameter, fiber appearance and fiber properties.
(1) Generally, they are classified based on different alkali metal oxide contents.
Alkali-free glass fiber
Medium-alkali glass fiber (C glass fiber)
High-alkali glass fiber (A glass fiber)
(2) Classification by monofilament diameter
Glass fiber monofilaments are cylindrical and can be divided into several types according to their diameters:
Coarse fiber: 30μm; primary fiber: 20μm
Intermediate fiber: 10μm~20μm;
Advanced fiber: 3μm~10μm (also called textile fiber);
Ultrafine fiber: The diameter of a single fiber is less than 4μm. The difference in the diameter of a single fiber not only affects the performance of the fiber, but also affects the production process, output and cost of the fiber. Generally, 5μm-10μm fibers are used as textile products; 10μm-14μm fibers are generally more suitable for making untwisted roving, non-woven fabrics, chopped fiber mats, etc.
(3) Classification by fiber performance
This is a new type of glass fiber that has been newly developed to meet special use requirements. The fiber itself has certain special and excellent properties. It can be roughly divided into:
High-strength glass fiber;
High modulus glass fiber;
High-temperature resistant glass fiber;
Alkali-resistant glass fiber;
Acid-resistant glass fiber;
Ordinary glass fiber
Optical fiber;
Low dielectric constant glass fiber;
Conductive fiber, etc.
Characteristics of glass fiber composite materials
Glass fiber is more heat-resistant than organic fiber, non-flammable, corrosion-resistant, has good heat and sound insulation, high tensile strength, and good electrical insulation. However, it is brittle and has poor wear resistance. It is used to make reinforced plastics or reinforced rubber. As a reinforcing material, glass fiber has the following characteristics, which make it more widely used than other types of fibers and its development speed is also far ahead. Its characteristics are listed below:
(1) High tensile strength and small elongation.
(2) High elastic modulus and good rigidity.
(3) Large elongation within the elastic limit and high tensile strength, so it absorbs a lot of impact energy.
(4) It is an inorganic fiber, non-flammable and has good chemical resistance.
(5) Low water absorption.
(6) Good dimensional stability and heat resistance.
(7) Good processability, can be made into products in different forms such as strands, bundles, felts, and woven fabrics.
(8) Transparent and can transmit light.
(9) The development of a surface treatment agent with good adhesion to resin has been completed.
(10) Fatigue resistance
The blades are made of different structures such as glass fiber, which are fatigue-resistant, allowing the helicopter to remain stable and parallel at high altitudes, giving full play to the structural characteristics of composite materials.
(11) Not easy to burn, can be melted into glass beads at high temperatures
Compared with traditional materials, glass fiber composite materials have two main characteristics, namely, performance designability and consistency between materials and component molding. The composite effect expected by glass fiber composite materials is the complementary performance of raw materials and the superposition effect, so that they have excellent physical and chemical properties that some raw materials do not have.
Application of glass fiber composite materials:
Compared with organic fibers, glass fibers are more heat-resistant, non-flammable, corrosion-resistant, have good heat and sound insulation, high tensile strength, and good electrical insulation. But the disadvantage is that they are brittle and have poor wear resistance.
Glass fibers are mainly used as electrical insulation materials, industrial filter materials, anti-corrosion, moisture-proof, heat-insulating, sound-insulating, and shock-absorbing materials. They can also be used as reinforcing materials to make reinforced plastics or reinforced rubber, reinforced gypsum, and reinforced cement products. Coating glass fibers with organic materials can improve their flexibility and be used to make packaging cloth, window screens, wall cloths, covering cloths, protective clothing, and electrical and sound insulation materials.
Secondly, continuous glass fibers are infinitely long fibers drawn by mechanical drawing methods through platinum alloy plates, commonly known as long fibers. Fixed-length glass fibers are non-continuous fibers made by rollers or airflows, also known as short fibers. Fine, short, and 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, board, tube, etc.
Finally, E-grade glass fiber is the most commonly used and widely used in electrical insulation materials; S-grade is a special fiber. Although the output is small, it is very important. Because of its super strength, it is mainly used in military defense, such as bulletproof boxes; C-grade is more chemically resistant than E-grade and is used for battery separators and chemical gas filters; A-grade is alkaline glass fiber, which is used to produce reinforcement materials.
Application of glass fiber in the aerospace field:
The aerospace field brings together the most advanced scientific and technological achievements in the world today, and is also a concentrated display of the scientific and technological level of new materials. High-performance glass fiber composites have become an indispensable material in the aerospace industry, and together with aluminum alloys, steel and titanium alloys, they have become the cornerstone of supporting the development of the aerospace industry.
In aviation, both civil airliners and military aircraft use glass fiber composite materials. Glass fiber reinforced materials effectively reduce the weight of aircraft, increase commercial load, save energy, and achieve the effect of light weight and beautiful appearance. It has the properties of corrosion resistance, high temperature resistance, radiation resistance, flame retardancy, and aging resistance.
Application of glass fiber in the field of electrical insulation:
Due to the characteristics of light weight, high strength, good insulation, fatigue resistance, corrosion resistance, convenient processing and molding, and easy maintenance, glass fiber composite materials have been widely used in the power industry. In addition to traditional power transmission and transformation equipment and facilities, glass fiber reinforced plastic towers and composite cable cores have become one of the hot spots of industry attention. Electrical insulation materials products can be divided into 8 categories, and there are 6 categories related to glass fiber, which is enough to illustrate the wide application of glass fiber in this industry. These 6 categories include:
(1) Insulation impregnation products
(2) Glass fiber reinforced plastic laminates
(3) Glass fiber molding compounds
(4) Mica products
(5) Insulation adhesives and replication products
(6) Electromagnetic wires
Application of glass fiber in the environmental field:
Ecological environment is an ecological factor necessary for human survival and development. The Chinese government has clearly pointed out that protecting the environment is a basic national policy that my country has long adhered to. Glass fiber has a wide range of applications in the atmosphere, water, biology, soil and other environmental fields due to its excellent performance.
For example, glass fiber filter materials have made considerable contributions in improving exhaust gas, composition, and reducing dust emissions. In addition, a glass fiber air filter paper can be used in air conditioning systems to remove odors from the air, thereby achieving the purpose of purifying the air. Glass fiber has a good application in water environment and soil environment. It is combined with organic fiber materials to be processed into geotechnical materials for preventing soil erosion.
Application of glass fiber in the biomedical field:
Due to the excellent properties of glass fiber, glass fiber fabric has the characteristics of high strength, non-hygroscopicity, and dimensional stability. Therefore, it can be used as orthopedic and repair materials, dental materials, medical equipment, etc. in the biomedical field.
Compared with traditional cotton plaster bandages, orthopedic bandages made of glass fiber fabric and various resins overcome the characteristics of low strength, hygroscopicity, and dimensional instability of previous bandages. In addition, practice has proved that glass fiber membrane filters have strong adsorption and capture capabilities for white blood cells, have a high white blood cell removal rate, and have excellent operating stability. In addition, glass fiber has been used as a gas filter for respirators for many years. This filter material has very little resistance to air and has a high bacterial filtration efficiency.
Application of glass fiber in the field of building materials:
Glass fiber reinforced cement
As we all know, the outstanding feature of cement-based building materials is high compressive strength but low bending, tensile and impact strength. With the in-depth research and development of glass fiber, the advent of alkali-resistant glass fiber has produced a new type of glass fiber reinforced cement material that overcomes the defects of cement matrix. This material can not only improve the bending and tensile strength of the cement matrix, but also improve its impact strength.
Glass fiber reinforced plastic has the main characteristics of light weight and high strength, and has good heat resistance, alkali resistance, corrosion resistance and electrical insulation. The application of glass fiber reinforced plastic in building materials includes lighting, sanitation, decoration, water supply and drainage, heating and ventilation, enclosure civil engineering, electrical, tooling and equipment, etc.
Application of glass fiber in the automotive industry:
Glass fiber and its composite materials can be used in automobiles to make: front end panels, air conditioning pipes, exhaust valves, engine hoods, bumpers, trunk lids, body panels, roof inner panels, chassis, seat components, instrument panels, mufflers, exhaust filters, fuel cylinders, interior materials, friction materials, etc.
The application field of glass fiber is constantly expanding. Glass fiber and its composite materials, with their light weight and high strength, can promote energy conservation and emission reduction in related industries. The construction industry and transportation industry are the largest application fields of glass fiber. At the same time, the demand for glass fiber in industries such as electronic information, new energy and electricity will continue to grow.
(1) High tensile strength and small elongation. 
