A Comprehensive Overview of Glass Fiber Classifications

YONGXING Fiberglass, one of China’s leading full-spectrum glass fiber manufacturers, is renowned for its diverse range of high-quality glass fiber products. The company’s commitment to innovation and excellence ensures that it offers a wide array of glass fibers tailored to meet various industrial needs. Glass fibers are crucial in numerous applications, from reinforcing materials to insulation, and understanding their classifications is key to selecting the right type for specific purposes.

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Classification of Glass Fibers

Glass fibers can be classified based on several criteria, including raw material composition, filament diameter, fiber appearance, and specific properties. Below is a detailed overview of these classification methods:

1. Classification Based on Raw Material Composition

This classification primarily pertains to continuous glass fibers and is distinguished by the content of alkali metal oxides, particularly sodium oxide (Na2O) and potassium oxide (K2O). Alkali metal oxides are introduced through raw materials like soda ash, glauber salt, and feldspar, and they play a significant role in lowering the glass melting point. However, a higher alkali content can reduce the chemical stability, electrical insulation properties, and strength of the glass.

Types of Continuous Glass Fibers Based on Alkali Content:

Alkali-Free Fibers (E-Glass): With an R2O content less than 0.8%, E-glass fibers are composed mainly of aluminosilicate. They offer excellent chemical stability, electrical insulation, and strength, making them ideal for electrical insulation, fiberglass reinforcement, and tire cord applications.
Medium Alkali Fibers: These fibers have an R2O content ranging from 11.9% to 16.4% and consist of sodium-calcium silicate. While they are not suitable for electrical insulation due to their higher alkali content, they still exhibit good chemical stability and strength. They are commonly used in latex fabrics, grid cloth substrates, acid-resistant filters, and window screens, as well as fiberglass reinforcement where electrical performance and strength requirements are moderate. Their cost-effectiveness also makes them widely used.
High Alkali Fibers: With an R2O content equal to or greater than 15%, these fibers are often made from recycled flat glass or bottles. They are used in applications requiring water and moisture resistance, such as battery separators, pipe wrapping cloth, and mats.
Specialty Glass Fibers: These include high-strength glass fibers composed of pure magnesium-aluminum-silicon trinary compounds, high-strength, high-elasticity fibers, chemical-resistant fibers composed of silica, aluminum, calcium, and magnesium, and other specialized types like alumina-containing fibers, high-silica fibers, and quartz fibers.

2. Classification Based on Filament Diameter

Glass fibers are also classified by their diameter, which affects their performance and production processes:

Coarse Fibers: These fibers have a diameter generally around 30 µm.
Primary Fibers: With diameters greater than 20 µm.
Intermediate Fibers: Diameters range from 10 to 20 µm.
Fine Fibers (Textile Fibers): These fibers have diameters between 3 to 10 µm. Fibers with diameters less than 4 µm are known as ultra-fine fibers.

Different filament diameters not only affect the fiber’s properties but also impact production techniques, yields, and costs. Fibers in the 5-10 µm range are typically used for textile products, while those in the 10-14 µm range are suited for applications like non twisted yarns, non-woven fabrics, and chopped strand mat.

3. Classification Based on Fiber Appearance

Glass fiber appearance, including form and length, depends on the production method and intended use:

Continuous Fibers: Also known as textile fibers, these are theoretically endless fibers produced via processes like the bushing method. They can be processed into fabrics, ropes, tapes, and non-twisted yarns.
Chopped Fibers: These fibers have a limited length, typically ranging from 300 to 500 mm, but can sometimes be longer. They are often used in mats and felts and include fibers produced by steam-blowing and other methods.
Glass Wool: Also known as glass mat, this type of fiber is short, usually less than 150 mm, and has a fluffy, cotton-like texture. It is primarily used for thermal insulation and soundproofing. Other forms include short-cut fibers, hollow fibers, glass fiber powder, and milled fibers.

4. Classification Based on Fiber Properties

This classification addresses the unique properties of specialized glass fibers designed for specific applications:

High-Strength Glass Fibers: These fibers offer superior tensile strength.
High-Modulus Glass Fibers: These fibers exhibit high rigidity and resistance to deformation.
High-Temperature Resistant Fibers: Designed to withstand extreme temperatures.
Alkali-Resistant Fibers: Resistant to alkaline environments.
Acid-Resistant Fibers: Designed to endure acidic conditions.
Standard Glass Fibers: Includes both alkali-free and medium alkali fibers.
Optical Fibers: Used for transmitting light signals.
Low Dielectric Constant Fibers: Offer low electrical conductivity.
Conductive Fibers: Designed to conduct electricity.

Conclusion

At YONGXING Fiberglass, we pride ourselves on offering a comprehensive range of glass fiber products tailored to meet the diverse needs of various industries. Our classification system ensures that each product is precisely suited for its intended application, from electrical insulation to high-strength reinforcement. By understanding these classifications, our customers can make informed decisions and select the optimal glass fiber solutions for their specific requirements.