How much do you know about fiberglass roving?

Glass fiber yarn/roving is an inorganic non-metallic material with excellent performance. It is usually used as a reinforcing material in composite materials, electrical insulating materials and thermal insulation materials, circuit substrates, etc., and is widely used in various fields of the national economy.

What is roving

Roving fiberglass is made of glass balls or waste glass through high temperature melting, wire drawing, winding, weaving and other processes. Finally, various products are formed. The diameter of glass fiber monofilament ranges from a few microns to more than 20 microns, which is equivalent to 1/20-1/5 of a hair. It is composed of thousands of monofilaments, and is usually used as a reinforcing material in composite materials, electrical insulating materials and thermal insulation materials, circuit substrates, etc., and is widely used in various fields of the national economy.

Properties of fiberglass roving

Glass is generally considered to be a hard and fragile object, and it is not suitable for use as a structural material. However, if it is drawn into silk, its strength will be greatly increased and it has flexibility. Therefore, it can finally become an excellent structural material after being given a shape with resin. Glass fibers increase in strength as their diameter decreases. As a reinforcing material, glass fiber has the following characteristics. These characteristics make the use of glass fiber far more extensive than other types of fibers, and the development speed is far ahead. Its characteristics are listed as follows:
1.High tensile strength and small elongation (3%).
2.High elastic coefficient and good rigidity.
3.The amount of elongation within the elastic limit is large and the tensile strength is high, so the absorption of impact energy is large.
4.It is an inorganic fiber, which is non-flammable and has good chemical resistance.
5.Low water absorption.
6.The dimensional stability and heat resistance are all good.
7.Good processability, can be made into different forms of products 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 was completed.

10.The price is cheap.

Classification

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 glass fiber, etc.

E-glass
Also known as alkali-free glass fiber, it is a borosilicate glass. It is 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 destroyed by inorganic materials. Acid attack, so it is not suitable for use in acidic environment.

C-glass
Also known as medium-alkali glass roving, its characteristics are chemical resistance, especially acid resistance, which is better than that of alkali-free glass, but its electrical properties are poor, and its mechanical strength is 10%~20% lower than that of alkali-free glass fiber. amount of boron trioxide, while China's medium-alkali glass fibers are completely boron-free. In foreign countries, medium-alkali glass fiber is only used for the production of corrosion-resistant glass fiber products, such as the production of glass fiber tissue mats, etc., and is also used to strengthen asphalt roofing materials, but in China, medium-alkali glass fiber accounts for more than half of the glass fiber output. (60%), 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 and has strong competitiveness.

high strength glass fiber
It is characterized by 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 the strength of E-glass fiber. The FRP products produced with them are mostly used in military industry, space, bulletproof armor and sports equipment. However, due to the high price, it cannot be promoted in civilian use, and the world's output is only about a few thousand tons.

AR fiberglass
Also known as alkali-resistant glass fiber, it is mainly developed to strengthen cement.

E-CR glass direct roving
It is an improved boron-free and alkali-free glass used to produce glass fiber with good acid and water resistance. New varieties developed for underground pipelines, storage tanks, etc.

Application of fiberglass roving

Untwisted rovings are bundled from parallel strands or parallel monofilaments. According to the glass composition, roving can be divided into: alkali-free glass roving and medium-alkali glass roving. The diameter of glass fibers used in the production of glass rovings ranges from 12 to 23 μm. The number of rovings ranges from 150 to 9600 (tex). Untwisted roving can be directly used in some composite material forming methods, such as winding and pultrusion process, because of its uniform tension, it can also be woven into fiberglass roving fabric, and in some applications, the untwisted roving is further chopped .

Fiberglass roving for spray up

The twist-free roving suitable for FRP injection molding should have the following properties: Good cutting performance, less static electricity generated during continuous high-speed cutting; The efficiency of the untwisted roving to be dispersed into raw yarn after cutting is high, that is, splitting High rate, usually more than 90%; The chopped strand has excellent mold coverage and can cover all corners of the mold; The resin penetrates quickly, it is easy to be flattened by rollers and easy to drive out air bubbles; It has good degradation performance and uniform thick yarn density, which is suitable for various spray guns and fiber conveying systems. The untwisted rovings for jetting are made of multiple strands of strands, and each strand contains 200 glass fiber monofilaments.

Fiberglass Roving for SMC

Roving for pultrusion

Pultrusion is used to manufacture various profiles with consistent cross-sections, which are characterized by high glass fiber content and high unidirectional strength. Rovings for pultrusion can be a combination of multiple strands or straight rovings with linear densities ranging from 1100 to 4400. The various performance requirements are roughly the same as those for winding rovings.

Direct roving for weaving

Status and Prospects

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 construction, transportation, electronics, electrical, chemical, metallurgy, environmental protection, national defense and other industries. Due to its wide application in many fields, glass fiber has been paid more and more attention by people. The world's largest glass fiber production and consumption countries are mainly developed countries such as the United States, Europe, and Japan, and their per capita glass fiber consumption is relatively high. Europe remains the largest region for glass fiber consumption, accounting for 35% of the global total.

The rapid development of China's glass fiber industry in recent years is driven by the domestic and foreign markets. The expansion of the international market is not only due to the growth of total demand, but also from the development space left for domestic companies in the international market after international companies withdrew from the industry due to low profit margins in the early stage; while the growth of the domestic market comes from downstream consumption. rapid development of the industry. After more than 50 years of development, China's glass fiber has become quite large.

In the long run, the strengthening and transformation of infrastructure in the Middle East and Asia-Pacific has increased the demand for glass fiber by a large amount. The outlook for the fiberglass industry remains positive. In addition, the application field of glass fiber has expanded to the wind power market, which may be a bright spot for the future development of glass fiber. The energy crisis has prompted countries to seek new energy sources, and wind energy has become a focus of attention. China has also begun to increase investment in the field of wind power. By 2020, China will invest 350 billion yuan in the field of wind power generation, of which about 20% (ie, 70 billion yuan) will need to use glass fibers (such as wind turbine blades, etc.). This is a big market for Chinese glass fiber enterprises.