Carbon fiber (CF) is a special material composed of carbon elements. Its carbon content usually exceeds 90%, and it has excellent mechanical properties such as being lightweight, high-strength, high-modulus, temperature-resistant, corrosion-resistant, and fatigue-resistant.

The production of carbon fiber generally involves two main steps:

1. Precursor Filament Production: Using polyacrylonitrile (PAN), pitch, rayon, or phenolic resins as precursors, a continuous filament is produced through a spinning process.

2. Carbonization: The precursor filament is subjected to high-temperature pre-oxidation and carbonization in an oxygen-free environment, transforming it into a high-purity carbon fiber.

Carbon fiber is typically used in the form of tow, fabric, felt, chopped fibers, or prepregs. It is often combined with a resin matrix (like epoxy resin) to form Carbon Fiber Reinforced Polymers (CFRPs), which are widely used in aerospace, automotive, sporting goods, wind power, and construction industries.

I. Classification of Carbon Fiber

There are many ways to classify carbon fibers. Here are a few common methods:

1. By Mechanical Properties

This is the most common classification method, based on the carbon fiber’s tensile strength and tensile modulus.

• High-Strength (HS) Carbon Fiber: High tensile strength but relatively low modulus. It’s often used in applications requiring high strength, such as aerospace structural components and high-pressure vessels.

• High-Modulus (HM) Carbon Fiber: High tensile modulus but relatively low strength. It’s often used in applications requiring high rigidity, such as satellite skeletons, optical instruments, and golf club shafts.

• High-Strength and High-Modulus (HSHM) Carbon Fiber: Possesses both high strength and high modulus. This type of carbon fiber has a balanced performance and is a key direction for future development.

2. By Precursor Material

Based on the precursor (raw filament) used to produce the carbon fiber, it can be classified as:

• Polyacrylonitrile-based (PAN-based) Carbon Fiber: This is the most widely produced and used type of carbon fiber. Its production process is relatively mature, and it offers excellent performance.

• Pitch-based Carbon Fiber: Made from petroleum or coal tar pitch. This type of carbon fiber usually has a very high modulus but relatively lower strength.

• Rayon-based Carbon Fiber: Made from rayon fiber, this type is now less commonly used.

• Phenolic-based Carbon Fiber: Made from phenolic resin, this type of carbon fiber has excellent high-temperature resistance and ablation resistance.

3. By Form

Based on the form in which the carbon fiber is used, it can be classified as:

• Continuous Filament: In the form of a continuous strand, typically used for weaving or filament winding to create structural components.

• Chopped Fiber: Continuous carbon fibers are cut into short lengths, often used to reinforce plastics, concrete, etc.

• Carbon Fiber Fabric: Continuous carbon fibers are woven into a cloth-like material for easier layering and composite molding.

• Carbon Fiber Mat: A non-woven mat of randomly oriented fibers, often used for non-structural or filler applications.

II. Multifunctional Advantages: Why Chinese Carbon Fiber Stands Out

The Chinese carbon fiber industry has been developing rapidly in recent years, demonstrating unique advantages in technology, cost, and market aspects. Here are some key advantages of Chinese carbon fiber:

1. Complete Industrial Chain and Large-Scale Production

China has established a complete industrial chain, from precursor fibers and prepregs to finished carbon fiber products and composite material applications. According to data from Carbon Fiber Circular (CCF), the total carbon fiber capacity in mainland China exceeded 160,000 tons in 2023, accounting for half of the global capacity. The actual production reached 97,600 tons, an increase of 41.3% year-on-year. This large-scale production capacity ensures a more stable supply of carbon fiber products, meeting the growing market demand.

2. Cost-Effectiveness

Compared to some traditional carbon fiber-producing countries, China has a cost advantage in labor, energy, and raw materials. Although carbon fiber production is a technology and capital-intensive industry, China’s technical advancements and economies of scale have given its products a good cost-performance ratio in the international market. For example, the price of domestic T700-grade general-purpose carbon fiber is often more competitive than imported products, especially in price-sensitive fields like wind turbine blades and sports equipment.

3. Strong R&D Capabilities and Technological Breakthroughs

China has invested significant resources into carbon fiber technology research and development. Some enterprises and research institutions have made remarkable progress in the R&D of high-performance carbon fiber. For instance, Zhongfu Shenying Carbon Fiber Co., Ltd. (SYT) has successfully achieved stable mass production of T1100-grade ultra-high-strength carbon fiber, which indicates that China is now among the world’s leaders in the high-performance carbon fiber sector. These technological breakthroughs provide solid support for high-end applications like aerospace and defense.

4. Huge Domestic Market Demand

China has one of the world’s largest manufacturing systems, with huge demand for carbon fiber in industries such as wind turbine blades, automobiles, and sports equipment. According to CCF data, the total demand for carbon fiber in mainland China was approximately 79,000 tons in 2023, with wind turbine blades contributing over 40,000 tons of that demand, accounting for the vast majority. The vast domestic market provides a solid foundation for Chinese carbon fiber enterprises and a broad testing ground for the application of new technologies and product iterations, creating a virtuous cycle.

III. Main Specifications and Parameters

The performance of carbon fiber is typically measured by a series of key parameters that determine its suitability for various applications.

1. Strength

Tensile Strength: This is the maximum stress a carbon fiber can withstand before breaking under tension. It is the most important parameter for measuring the fiber’s tensile capacity, typically measured in Megapascals (MPa) or Gigapascals (GPa). For example, the tensile strength of T700-grade carbon fiber is usually around 4.9 GPa.

2. Modulu

Tensile Modulus: Also known as Young’s Modulus, it indicates the stiffness of the material during elastic deformation. A higher modulus means the material is more resistant to deformation. The unit is typically GPa. For example, the tensile modulus of high-modulus carbon fiber (such as M55J) can exceed 540 GPa, while T700-grade is around 230 GPa.

3. Density

Density: Refers to the mass per unit volume of the carbon fiber. One of the key advantages of carbon fiber is its high strength-to-weight ratio. The density of carbon fiber is generally between 1.7 and 2.0 grams per cubic centimeter (g/cm³), which is significantly lower than steel (7.8 g/cm³) or aluminum (2.7 g/cm³).

4. Filament Count (Tow Size)

Filament Count: Refers to the number of individual filaments in a single tow of carbon fiber. Common sizes include:

• • • Small Tow: Typically 1K, 3K, 6K, or 12K, where K represents 1,000 filaments. Small tows are used for high-precision applications, such as aerospace and high-end sports equipment.
    • Large Tow: Typically 24K, 48K, or higher, such as 320K and 480K. Large tows are more cost-effective and are commonly used in industrial applications, such as wind turbine blades and automotive parts.

5. Sizing

Sizing: A chemical coating applied to the surface of carbon fibers. This treatment improves the interfacial adhesion between the fiber and the matrix resin (e.g., epoxy resin), thereby enhancing the mechanical properties and processability of the composite material. Different sizing formulations are designed for specific resin systems.

IV. Industrial Clusters: Where to Find Carbon Fiber Manufacturers in China

The development of China’s carbon fiber industry shows distinct regional cluster characteristics, primarily concentrated in a few core areas. These clusters integrate R&D, production, and application resources, forming a complete industrial chain ecosystem.