Carbon Fiber Classification: Based on Tensile Strength and Elastic Modulus

Elastic modulus refers to the material's elasticity during stretching, with its value representing the ratio of the force required to stretch a unit length of material to its cross-sectional area (expressed in M values). The higher the tensile modulus, the stronger the material's resistance to stretching, meaning that under external force, the material's shape is less likely to change and it can withstand greater tensile forces, thus exhibiting better tensile properties.

Tensile strength refers to the maximum tensile stress a sample can withstand in a tensile test, typically expressed in MPa (T value), until the sample breaks. The domestic advancement of carbon fiber technology mainly focuses on the development and engineering application of processes for producing higher-strength (e.g., T1100 grade) and higher-modulus (e.g., M55 grade) carbon fibers.

Carbon Fiber Classification: Large Tow Fibers Have Lower Costs, Small Tow Fibers Offer Better Performance

Carbon fibers can be classified into small tow and large tow based on the number of fibers. Small tow carbon fibers have reached high levels of mechanical properties and other indicators, but their production process is difficult and costly. They are mainly used in high-tech fields such as aerospace and military industries, as well as in high-value products in sports goods, such as airplanes, missiles, rockets, satellites, fishing rods, golf clubs, and tennis rackets. On the other hand, large tow carbon fibers have relatively lower performance but also lower production costs. Therefore, they are typically used in basic industrial fields, including wind turbine blades, building reinforcement, automotive components, and hydrogen storage tanks. Compared to small tow fibers, large tow carbon fibers' main advantage is their ability to significantly increase the single-filament production capacity under the same production conditions, thus reducing production costs. Their layup efficiency in composite material preparation is also higher, with production costs reduced by over 30%. This helps overcome the price limitations of carbon fiber and expands its application range, laying the foundation for broader use of carbon fiber composites. Once the raw material costs of large tow carbon fibers are reduced, the downstream production costs for processing finished products also decrease, improving profitability. Therefore, the competitive advantage of the large tow carbon fiber industry's upstream and downstream supply chain lies in this cost reduction.