Basic Knowledge and Application of Glass Fiber

 

 

Basic Knowledge of Glass Fiber

Glass fiber (original English name: glass fiber or fiberglass) is an inorganic non-metallic material with excellent performance. There are 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 as raw materials through high-temperature melting, wire drawing, winding, weaving and other processes. The diameter of its single filament is several 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.

 

Physical Properties of Glass Fiber

Melting point 680 ℃

Boiling point 1000 ℃

Density 2.4-2.7g/cm³

 

Chemical Composition

The main components are silicon dioxide, aluminum oxide, calcium oxide, boron oxide, magnesium oxide, sodium oxide, etc. According to the alkali content in the glass, it can be divided into alkali-free glass fiber (sodium oxide 0%~2%, alumina borosilicate glass), medium alkali glass fiber (sodium oxide 8%~12%, boron-containing or non-boron-containing sodium-lime silicate glass) and high alkali glass fiber (sodium oxide more than 13%, sodium-lime silicate glass).

 

Raw Materials and Their Applications

Glass fiber is more heat-resistant than organic fiber, non-flammable, corrosion-resistant, heat-insulating and sound-insulating, with high tensile strength and good electrical insulation. But it is brittle and has poor wear resistance. Used to make reinforced plastics or reinforced rubber, glass fiber has the following characteristics as a reinforcing material. These characteristics make the use of glass fiber far more extensive than other types of fibers, and the development speed is also far ahead. Its characteristics are listed as follows:

(1) High tensile strength and small elongation (3%).

(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) Dimensional stability and heat resistance are both good.

(7) Good processability, can be made into products in different forms such as strands, bundles, felts, and woven fabrics.

(8) Made into transparent products that can transmit light.

(9) The development of surface treatment agents with good adhesion to resins has been completed.

(10) Low price.

(11) Not easy to burn, can be melted into glass beads at high temperatures.

According 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 (alkali-resistant) glass fiber, etc.

 

Main Raw Materials for Glass Fiber Production

At present, the main raw materials for domestic glass fiber production are quartz sand, alumina and pyrophyllite, limestone, dolomite, boric acid, soda ash, mirabilite, fluorite, etc.

 

Production Method

It can be roughly divided into two categories: one is to make molten glass directly into fibers;

 

The other is to make molten glass into glass balls or rods with a diameter of 20mm first, and then heat and remelt it in various ways to make very fine fibers with a diameter of 3 to 80μm.

 

The infinitely long fibers drawn by mechanical drawing method through platinum alloy plates are called continuous glass fibers, commonly known as long fibers.

 

The non-continuous fibers made by rollers or airflow are called fixed length glass fibers, commonly known as short fibers

 

Glass Fiber Classification

Glass fiber is divided into different grades according to its composition, properties and uses.

According to the standard grade regulations, E-grade glass fiber is the most commonly used and widely used in electrical insulation materials;

 

S-Grade is a Special Fiber

The glass used to produce glass fiber is different from the glass used in other glass products.

The glass components used for commercialized fibers internationally are as follows:

 

1) E-glass

Also known as alkali-free glass, it is a borosilicate glass. It is currently the most widely used glass component for glass fiber. It has good electrical insulation and mechanical properties. It is widely used in the production of glass fiber for electrical insulation and is also widely used in the production of glass fiber for FRP. Its disadvantage is that it is easily corroded by inorganic acids, so it is not suitable for use in acidic environments.

 

2) C-glass

Also known as medium-alkali glass, its characteristics are that its chemical resistance, especially acid resistance, is better than that of alkali-free glass, but its electrical properties are poor, and its mechanical strength is 10% to 20% lower than that of alkali-free glass fiber. Usually, foreign medium-alkali glass fibers contain a certain amount of boron trioxide, while my country’s medium-alkali glass fibers do not contain boron at all.

In foreign countries, medium-alkali glass fiber is only used to produce corrosion-resistant glass fiber products, such as glass fiber surface felt, and is also used to reinforce asphalt roofing materials. However, in my country, medium-alkali glass fiber accounts for more than half (60%) of glass fiber production and is widely used in the reinforcement of FRP and the production of filter fabrics, wrapping fabrics, etc. Because its price is lower than that of alkali-free glass fiber, it has strong competitiveness.

 

3) High-Strength Glass Fiber

Its characteristics are high strength and high modulus. Its single fiber tensile strength is 2800MPa, which is about 25% higher than that of alkali-free glass fiber, and its elastic modulus is 86000MPa, which is higher than that of E-glass fiber. The FRP products produced by them are mostly used in military industry, space, bulletproof armor and sports equipment. However, due to its high price, it cannot be promoted in civilian use today, and the global output is only about a few thousand tons.

 

4) AR Glass Fiber

Also known as alkali-resistant glass fiber, alkali-resistant glass fiber is the rib material of glass fiber reinforced (cement) concrete (GRC for short). It is 100% inorganic fiber and is an ideal substitute for steel and asbestos in non-load-bearing cement components.

The characteristics of alkali-resistant glass fiber are good alkali resistance, which can effectively resist the erosion of high-alkali substances in cement, strong bond strength, extremely high elastic modulus, impact resistance, tensile strength, and bending strength, non-flammability, frost resistance, temperature and humidity resistance, excellent crack resistance and impermeability, strong designability and easy molding. Alkali-resistant glass fiber is a new type of green and environmentally friendly reinforcement material widely used in high-performance reinforced (cement) concrete.

 

5) A Glass

Also known as high-alkali glass, it is a typical sodium silicate glass. Due to its poor water resistance, it is rarely used in the production of glass fiber.

 

6) E-CR Glass

It is an improved boron-free alkali-free glass used to produce glass fibers with good acid and water resistance. Its water resistance is 7 to 8 times better than that of alkali-free glass fibers, and its acid resistance is much better than that of medium-alkali glass fibers. It is a new variety developed specifically for underground pipelines, storage tanks, etc.

 

7) D Glass

Also known as low-dielectric glass, it is used to produce low-dielectric glass fibers with good dielectric strength.

 

In addition to the above glass fiber components, a new alkali-free glass fiber has now appeared. It is completely free of boron, thereby reducing environmental pollution, but its electrical insulation and mechanical properties are similar to those of traditional E glass.

 

There is also a glass fiber with a double glass component, which has been used in the production of glass wool and has potential as a fiberglass reinforcement material. In addition, there is fluorine-free glass fiber, which is an improved alkali-free glass fiber developed for environmental protection requirements.

 

Identify High-alkali Glass Fiber

The simple method of inspection is to put the fiber in boiling water and boil it for 6-7 hours. If it is high-alkali glass fiber, after boiling in boiling water, the fibers in the warp and weft directions become loose.

 

There are two types of Glass Fiber Production Processes

1. a) Two-time molding-crucible drawing method;
2. b) One-time molding-tank kiln drawing method.

The crucible drawing method has many processes. First, the glass raw materials are melted at high temperature to form glass balls, and then the glass balls are melted again and drawn at high speed to form glass fiber raw yarn. This process has various disadvantages such as high energy consumption, unstable molding process, and low labor productivity. It has basically been eliminated by large glass fiber manufacturers.

 

Typical Glass Fiber Process

The tank kiln drawing method melts raw materials such as pyrophyllite in the kiln into a glass solution, removes bubbles, and transports them to the porous leak plate through the passage, and draws them into glass fiber raw yarn at high speed. The kiln can connect hundreds of leak plates through multiple passages to produce at the same time.

This process is simple, energy-saving and consumption-reducing, has stable molding, high efficiency and high yield, and is convenient for large-scale fully automated production. It has become the mainstream international production process, and the glass fiber produced using this process accounts for more than 90% of the global output.

 

 

Introduction to Common Qualities of Glass Fiber

 

Untwisted Roving

Untwisted roving is made of parallel raw filaments or parallel monofilaments. Untwisted roving can be divided into alkali-free glass untwisted roving and medium-alkali glass untwisted roving according to the glass composition. The diameter of glass fiber used to produce glass roving ranges from 12 to 23μm. The number of untwisted roving ranges from 150 to 9600 (tex). Untwisted roving can be directly used in some composite material forming methods, such as winding and pultrusion processes. Because of its uniform tension, it can also be woven into untwisted roving fabrics. In some uses, the untwisted roving is further chopped.

 

(1) Untwisted Roving for Spraying

Untwisted roving suitable for FRP spraying molding should have the following properties:

①Good cutting performance, less static electricity generated during continuous high-speed cutting;

②High efficiency of dispersion of untwisted roving into raw yarn after cutting, that is, high bundle rate, usually required to be more than 90%;

③The raw yarn after short cutting has excellent mold coverage and can cover every corner of the mold;

④Quick resin penetration, easy to be rolled flat by rollers and easy to drive away bubbles;

⑤Good raw yarn decomposition performance, uniform yarn density, suitable for various spray guns and fiber delivery systems. Untwisted roving for spraying is made of multiple strands of raw yarn, each strand of raw yarn contains 200 glass fiber monofilaments.

 

(2) Untwisted Roving for SMC

SMC is sheet molding compound, which is mainly used for pressing automotive parts, bathtubs, water tank panels, septic tanks, various seats, etc. When manufacturing SMC sheets, the SMC roving must be cut into lin (25mm) lengths and dispersed in the resin paste.

 

Therefore, the requirements for SMC roving are good short-cutting properties, less lint, excellent antistatic properties, and the chopped strands will not adhere to the knife roller during cutting. For colored SMC, the roving must be soaked in the resin paste with a high pigment content. Usually, SMC roving is generally 2400tex, and in a few cases, 4800tex is also used.

 

(3) Winding Roving

The winding method is used to manufacture glass fiber reinforced plastic pipes, storage tanks, etc. of various calibers. The number of winding roving ranges from 1200 to 9600. Winding large pipes and storage tanks tends to use direct roving, such as 4800tex direct roving.

 

The requirements for untwisted roving for winding are as follows:

① Good tape-forming property, in the form of a flat tape;

② Good untwisted roving debonding property, no unwinding when unbundling from the yarn tube, and no “bird’s nest”-like messy yarn;

③ Uniform tension, no drooping phenomenon;

④ Uniform linear density, generally less than ±7%;

⑤ Good permeability of untwisted roving, easy to be wetted and permeated by resin when passing through the resin tank.

 

(4) Untwisted Roving for Pultrusion

Pultrusion is used to manufacture various profiles with consistent cross-sections. It is characterized by high glass fiber content and high unidirectional strength. Untwisted roving for pultrusion can be a combination of multiple strands of raw silk or a direct untwisted roving, and its linear density ranges from 1100 to 4400. Various performance requirements are roughly the same as those for winding untwisted roving.

 

(5) Untwisted Roving for Weaving

An important use of untwisted roving is to weave gingham or unidirectional untwisted roving fabrics of various thicknesses, which are mostly used in the hand lay-up FRP forming process. The following requirements are imposed on untwisted roving for forced weaving:

①Good wear resistance;

②Good tape-forming property;

③Untwisted roving for weaving must be forced dried before weaving;

④The tension of the untwisted roving is uniform, and the drape should meet certain standards;

⑤The untwisted roving has good decomposition property;

⑥The untwisted roving has good permeability.

 

(6) Untwisted Roving for Preform

In the preform process, the untwisted roving is chopped and sprayed on a net of a predetermined shape, and a small amount of resin is sprayed at the same time to fix the fiber mesh into shape. Then the formed fiber mesh is moved into a metal mold, and the resin is injected and hot-pressed to obtain the finished product. The performance requirements for untwisted roving in this process are basically the same as those for spray-on untwisted roving.

 

Untwisted Roving Fabric

The gingham is a plain woven fabric with untwisted roving, which is an important base material for hand-laid FRP. The strength of the gingham is mainly in the warp and weft directions of the fabric. For occasions requiring high strength in the warp or weft directions, it can also be woven into a unidirectional gingham, which can arrange more untwisted roving in the warp or weft directions.

 

The quality requirements for the gingham are as follows:

① The fabric is uniform, the edges are straight, the surface is flat and mat-like, without stains, fuzz, creases, wrinkles, etc.;

② The warp and weft density, area weight, cloth width and roll length all meet the standards;

③ It is wound on a firm paper core and wound neatly;

④ Rapid and good resin permeability;

⑤ The dry and wet mechanical strength of the laminated material made of the fabric should meet the requirements.

The composite material formed by paving with gingham is characterized by low interlayer shear strength, poor pressure resistance and fatigue strength.

 

Glass Fiber Mat

 

(1)Chopped Strand Mat

Cut the glass strands (sometimes untwisted roving) into 50 mm long and lay them randomly but evenly on a mesh belt. Then apply an emulsion binder or sprinkle a powder binder on it and heat and cure it to form a chopped strand mat. Chopped Strand Mat is mainly used in hand lay-up, continuous board making, die pressing and SMC processes. The quality requirements for chopped strand mat are as follows:

 

①Uniform area quality along the width direction;

②The chopped strands are evenly distributed on the mat surface, no large holes are formed, and the binder is evenly distributed;

③It has moderate dry mat strength;

④Excellent resin impregnation and permeability.

 

(2) Continuous Strand Mat

The glass strands formed during the drawing process or the continuous strands decomposed from the strand tube are laid in an 8-shaped pattern on a continuous moving mesh belt and bonded with a powder binder. The fibers in the continuous glass fiber strand mat are continuous, so its reinforcing effect on the composite material is better than that of chopped strand mat. It is mainly used in processes such as pultrusion, RTM, pressure bag and glass mat reinforced thermoplastic (GMT).

 

(3) Surface Veil

FRP products usually need to form a resin-rich layer, which is generally achieved by using medium-alkali glass surface felt. Since this type of felt is made of medium-alkali glass (C), it gives FRP chemical resistance, especially acid resistance. At the same time, because the felt is thin and the glass fiber diameter is fine, it can also absorb more resin to form a resin-rich layer, covering the texture of glass fiber reinforced materials (such as gingham cloth) and playing a surface modification role.

 

(4) Needle Felt

Needle felt can be divided into short-cut fiber needle felt and continuous filament needle felt. Short-cut fiber needle felt is made by cutting glass fiber roving into 50mm and randomly laying it on a substrate pre-placed on a conveyor belt. It is then needled with a barbed needle. The needle pierces the short-cut fibers into the substrate, and the hook lifts some fibers upward to form a three-dimensional structure. The substrate used can be a thin fabric of glass fiber or other fibers. This needle-punched felt has a fluffy feel. Its main uses include use as thermal insulation and sound insulation materials, heat lining materials, and filter materials. It can also be used in the production of FRP, but the strength of the produced FRP is low and its scope of use is limited. Another type of continuous strand needle-punched felt is a felt in which continuous glass strands are randomly thrown onto a continuous mesh belt by a throwing device and needled by a needle plate to form a three-dimensional structure in which the fibers are interconnected. This felt is mainly used in the production of glass fiber reinforced thermoplastic stampable sheets.

 

(5) Stitched Mat

Short-cut glass fibers ranging from 50 mm to 60 cm in length can be stitched into short-cut fibers or long-fiber felts by a stitching machine. The former can replace traditional short-cut felts bonded with adhesives in some applications, while the latter can replace continuous strand felts to a certain extent. Their common advantages are that they do not contain adhesives, thus avoiding pollution in the production process. At the same time, they have good penetration and bonding properties and are relatively low in price.

 

Grinded Fibers

 

(1) Chopped Strands

Chopped strands are divided into dry chopped strands and wet chopped strands. The former is used in the production of reinforced plastics, while the latter is used in papermaking. Chopped strands used for FRP are divided into two categories: chopped strands for reinforcing thermosetting resins (BMC) and chopped strands for reinforcing thermoplastic resins. The requirements for chopped strands for reinforcing thermoplastics are that they use alkali-free glass fibers, have high strength and good electrical insulation, and that the chopped strands have good bundling, good fluidity, and high whiteness. Chopped strands for reinforcing thermosetting plastics require good bundling, easy to be quickly impregnated by resin, and have good mechanical strength and electrical properties.

 

(2) Grinded Fibers

Grinded fibers are made by grinding chopped fibers in a hammer mill or a ball mill. Milled fiber is mainly used as a reinforcing material in the reinforced reaction injection molding process (RRIM). It is used as a filler for resin in the manufacture of cast products, molds and other products to improve surface cracking and reduce molding shrinkage. It can also be used as a reinforcing material.

 

Glass Fiber Fabrics

The following introduces various glass fiber fabrics woven with glass fiber yarns.

 

Glass Cloth

The glass cloth produced in my country is divided into two categories: alkali-free and medium-alkali. Most of the foreign ones are alkali-free glass cloth. Glass cloth is mainly used to produce various electrical insulation laminates, printed circuit boards, various vehicle bodies, storage tanks, boats, molds, etc. Medium-alkali glass cloth is mainly used to produce plastic-coated packaging cloth and for corrosion-resistant occasions. The characteristics of the fabric are determined by the fiber performance, warp and weft density, yarn structure and weave. The warp and weft density is determined by the yarn structure and weave. The warp and weft density plus the yarn structure determine the physical properties of the fabric, such as weight, thickness and breaking strength. There are five basic weaves: plain, twill, satin, rib and mat.

 

Glass Tape

Glass tape is divided into woven edge tape and non-woven edge tape (raw edge tape). The main weaving method is plain weave. Glass tape is often used to manufacture high-strength electrical equipment parts with good dielectric properties.

 

Unidirectional Fabric

Unidirectional fabric is a four-warp broken satin or long-axis satin fabric woven with coarse warp yarn and fine weft yarn. Its characteristic is that it has high strength in the main direction of the warp yarn.

 

Three-dimensional Fabric Three-dimensional Fabric

Compared to flat fabric, its structural characteristics have developed from one-dimensional and two-dimensional to three-dimensional, so that the composite material with it as a reinforcement has good integrity and conformability, and greatly improves the interlaminar shear strength and damage tolerance of the composite material. It has developed with the special needs of aerospace, aviation, weapons, ships and other departments. Today, its application has expanded to automobiles, sports equipment, medical equipment and other departments. There are five main categories: woven three-dimensional fabrics, knitted three-dimensional fabrics, orthogonal and non-orthogonal non-woven three-dimensional fabrics, three-dimensional woven fabrics and other forms of three-dimensional fabrics. The shapes of three-dimensional fabrics include blocks, columns, tubes, hollow truncated cones, and special-shaped cross-sections with variable thickness.

 

Special-Shaped Fabrics

The shape of special-shaped fabrics is very similar to the shape of the product they are intended to reinforce, and must be woven on a special loom. Symmetrical special-shaped fabrics include: round caps, cones, caps, dumbbell-shaped fabrics, etc., and can also be made into asymmetrical shapes such as boxes and hulls.

 

Grooved Core Fabrics

Grooved core fabrics are made of two layers of parallel fabrics connected by vertical strips, and their cross-sectional shapes can be triangular or rectangular.

 

Glass Fiber Stitched Fabrics

Also called knitted felt or woven felt, it is different from ordinary fabrics and felt in the usual sense. The most typical stitched fabric is a layer of warp yarns and a layer of weft yarns overlapped, and the warp yarns and weft yarns are woven together by stitching to form a fabric.

 

Combined Glass Fiber

Since the 1970s, there have been reinforcing materials that combine chopped strand mat, continuous strand mat, untwisted roving fabric and untwisted roving in a certain order. There are generally the following types:

(1) Chopped strand mat + untwisted roving fabric

(2) Chopped strand mat + untwisted roving cloth + chopped strand mat

(3) Chopped strand mat + continuous strand mat + chopped strand mat

(4) Chopped strand mat + random untwisted roving

(5) Chopped strand mat or cloth + unidirectional carbon fiber

(6) Chopped strand + surface mat

(7) Glass cloth + unidirectional untwisted roving or glass thin rod + glass cloth

 

Glass Fiber Wet-Laid Mat

Glass fiber non-woven fabric series products originated in Europe and were later introduced to the United States, Japan, China and other countries. my country has established several large-scale production lines, with the main technology coming from German technology, such as Changzhou Zhongxing Tianma and Shaanxi Walter.

 

The main categories of domestic glass fiber wet-process felt are as follows:

 

(1) Roofing Veil: used as the base material for waterproof materials such as modified asphalt waterproofing rolls and colored asphalt tiles

(2) Pipeline Veil: used for covering oil and gas pipelines, combined with asphalt to prevent underground pipeline corrosion

(3) Surface Veil: used for shaping and surface polishing of FRP products

(4) Veneer Tissue: used for walls and ceilings to prevent cracking and orange peel of paint, mostly used for decorating large conference rooms and high-end hotels

(5) Floor Tissue: used as the base material for PVC floors

(6) Carpet Veil: used as the base material for square carpets

(7) Copper-clad Laminate Veil: attached to copper-clad laminate to enhance its punching and drilling performance

(8) Battery Separator Tissue: used as the base material for aluminum-acid battery separator felt.

 

Glass Fiber Cloth

Main use: FRP industry (accounting for about 70%). Glass fiber cloth is also used in the construction industry, and its main function is to increase strength. It is also used as building exterior wall insulation, interior wall decoration, interior wall moisture and fireproof, etc.

 

Glass fiber cloth varieties: glass fiber mesh cloth, glass fiber lattice cloth, glass fiber plain cloth, glass fiber axial cloth, glass fiber wall cloth, glass fiber electronic cloth.

 

Function of Glass Fiber:

 

Enhance Rigidity and Hardness. The increase of glass fiber can improve the strength and rigidity of plastics, but the toughness of the same plastic will decrease. Example: bending modulus;

 

Improve heat resistance and heat deformation temperature; taking nylon as an example, the heat deformation temperature of nylon with added glass fiber is at least twice as high. The general glass fiber reinforced nylon can reach a temperature of more than 220 degrees

 

Improve Dimensional Stability and Reduce Shrinkage;

 

Reduce Warping Deformation;

 

Reduce Creep;

 

For flame retardant properties, the candle wick effect will interfere with the flame retardant system and affect the flame retardant effect;

 

Reduce the Gloss of the Surface;

 

Increase Hygroscopicity;

 

Glass Fiber Treatment:

The length of glass fiber directly affects the brittleness of the material. If the glass fiber is not properly processed, short fibers will reduce the impact strength, while long fibers will increase the impact strength. In order to prevent the brittleness of the material from decreasing significantly, it is necessary to select glass fibers of a certain length.

 

Conclusion:

To obtain good impact strength, the surface treatment of glass fiber and the length of glass fiber are crucial!

 

Fiber Content:

The fiber content of the product is also a key issue. my country generally adopts integer contents such as 10%, 15%, 20%, 25%, 30%, etc., while foreign countries determine the glass fiber content according to the purpose of the product.

 

9 Anti-skid on ice

In April 2015, Canadian scientists developed a cheap and effective method to embed glass fiber into elastic rubber. This new material can be used to make anti-skid shoes in winter. The material is made of a rubber plastic called thermoplastic polyurethane. Thousands of glass fibers are embedded in it and extend to the outside of the rubber like tiny nails, making the rubber feel like fine sandpaper.

 

International Market

Glass fiber is a very good substitute for metal materials. With the rapid development of the market economy, glass fiber has become an indispensable raw material for industries such as construction, transportation, electronics, electrical, chemical, metallurgy, environmental protection, and national defense. Due to its wide application in many fields, glass fiber is increasingly valued by people. The major countries in the world in terms of glass fiber production and consumption are mainly developed countries such as the United States, Europe, and Japan, which have high per capita glass fiber consumption. Europe is still the largest region for glass fiber consumption, accounting for 35% of the global total consumption.

 

Domestic Market

After years of development, the quality of my country’s glass fiber enterprises has reached the upstream level, and the proportion of deep-processed products has increased year by year. The gross profit margin of leading enterprises in China’s glass fiber industry is between 25-35%, which is significantly higher than the 10% gross profit margin of foreign giants. The world’s glass fiber industry has long been an oligopoly. As a new force, China has an average annual capacity growth rate of more than 20% in recent years. It is expected to occupy more than 60% of the global market this year and become a new oligopoly in the international glass fiber market.

 

The rapid development of China’s glass fiber industry in recent years has been driven by both domestic and foreign markets. The expansion of the international market is due to both the growth of total demand and the development space left for domestic enterprises in the international market after international enterprises withdrew from the industry due to low profit margins in the early stage; while the growth of the domestic market comes from the rapid development of downstream consumer industries. After more than 50 years of development, China’s glass fiber has become quite large.

Compared with the international market, my country’s glass fiber products have fewer varieties and specifications and a narrow range of applications. However, these situations also show from another perspective that there is still a lot of market space in my country’s glass fiber industry that has not been tapped, especially in some application areas, and many market segments have not even been developed at all.

 

In the last few years of the 20th century, in order to meet market requirements, the glass fiber industry has seen gratifying changes in both overall output and output changes of various advanced glass fiber products.

 

my country’s glass fiber industry belongs to an export-oriented structure, and imports and exports have been growing in both directions. Especially with the vigorous development of the glass fiber industry, imports and exports have maintained rapid growth. In 2021, exports have reached 61.1% of the total glass fiber output. The high import and export ratio shows that my country’s glass fiber industry has been fully integrated with the international glass fiber market, and the improvement in product output and quality has greatly enhanced the international market competitiveness of my country’s glass fiber industry. On the other hand, the continued steady development of my country’s economy has also increased domestic demand for advanced foreign glass fiber products. This healthy export-oriented structure leads to a virtuous circle.

 

my country’s glass fiber industry has always been in a deficit state in the past, but the difference between exports and imports has been narrowing. In the first half of 2004, it achieved a trade surplus of 59.1755 million US dollars for the first time, completely reversing the situation where imports exceeded exports in the entire industry.

 

Because of this, domestic excellent glass fiber industry manufacturers pay more and more attention to the research on the industry market, especially the in-depth research on the development environment of enterprises and the changes in customer demand trends. A large number of domestic excellent glass fiber enterprises have risen rapidly and gradually become the leaders in the glass fiber industry!

 

In the long run, the strengthening and transformation of infrastructure in the Middle East and Asia-Pacific will increase the demand for glass fiber. With the growing global demand for glass fiber in glass fiber modified plastics, sports equipment, aerospace and other aspects, the prospects for the glass fiber industry are still optimistic. In addition, the application field of glass fiber has expanded to the wind power market, which may be a highlight of the future development of glass fiber. The energy crisis has prompted countries to seek new energy. Wind energy has become a focus of attention today, and China has also begun to increase investment in the field of wind power. By 2022, China will invest 1 trillion yuan in wind power generation, of which about 20% (or 200 billion yuan) will require the use of glass fiber (such as wind turbine blades, etc.).

 

Application of Glass Fiber

 

Glass fiber products are widely used in various fields of the national economy, among which electronics, transportation and construction are the three main application fields, and also represent the development trend of the world’s glass fiber industry in the next few years.

 

In summary, the application of glass fiber in abrasives and grinding tools accounts for a small proportion, and it is only one type of glass fiber products. In order to improve the overall quality level of abrasives and grinding tools, especially resin abrasive slices and grinding discs, the focus is on improving the high strength and high lateral impact resistance of the products. We also need to introduce some new varieties in the glass fiber industry and make good applications. It becomes easy to achieve ultra-high speed of resin slices and grinding discs. As a reinforcing material for abrasives and grinding tools, glass fiber still has a lot of room for development and expansion, and colleagues are required to work together.