Carbon fiber is a light and strong fiber composed mostly of carbon. Carbon fiber is made by flame-proofing an organic compound in fibrous form, followed by a high-temperature heat treatment (sintering) at 1,800°F or higher to remove hydrogen and nitrogen atoms from the raw organic compound, resulting in a carbon atom content of 90% or higher. Applications of Carbon Fiber Carbon fiber is used in many fields as a substitute for metal materials, taking advantage of its ability to reduce weight while maintaining strength. In addition, its flexibility, electronic conductivity, corrosion resistance, and flame resistance make it suitable for a wide range of applications. Carbon fiber is rarely used on its own; instead, it is generally used as a composite material combined with materials such as resins, ceramics, and metals. Specifically, carbon fiber is used in aircraft, rockets, and satellites, which require lightweight and high strength. It is also used in surgical orthotics such as artificial limbs, and nursing care equipment such as wheelchairs and nursing care beds, because of its lightness and ease of handling. Particularly in the automotive industry, carbon fiber can contribute to lower fuel consumption by reducing the weight of vehicles. For this reason, carbon fiber has attracted attention and has been used in racing vehicles since the early days of its development. Carbon fiber also has applications in the sporting goods field, such as golf shafts, fishing rods, reels, bicycle frames, tennis rackets, skis, and snowboards, due to its high strength and elastic modulus. In the future, carbon fiber is also expected to be used in the construction and civil engineering fields, for example, by attaching carbon fiber sheets to concrete structures to reinforce their earthquake resistance and as a substitute material for cables and steel frames in suspension bridges. Types of Carbon Fiber Carbon fiber is classified into two types based on raw materials: PAN-based carbon fiber and pitch-based carbon fiber. Currently, PAN-based carbon fiber is the mainstream, accounting for 90% of the global production of carbon fiber. 1. PAN-Based Carbon Fiber Carbon fiber made from PAN (polyacrylonitrile) fiber has extremely high strength and modulus and is widely used in industrial fields that require high reliability, such as the space industry, and in more familiar applications, such as leisure goods and sports. The most common use of carbon fiber is in the industrial field. In the automotive field, it is used in hoods, spoilers, gasoline tanks, and many other parts. It is also used as a substitute material for metal parts, such as leaf springs and gears. 2. Pitch-Based Carbon Fiber Pitch-based carbon fiber has the feature of adjustable modulus of elasticity. For this reason, it is used in parts that do not require high elasticity and, conversely, in products that do require high elasticity. Pitch-based carbon fiber is further classified into mesophase pitch fiber and isotropic pitch fiber. Mesophase pitch is a high-performance carbon fiber (HPCF) with high strength and high modulus. Isotropic pitch, on the other hand, has randomly oriented molecules and is optically isotropic. The resultant isotropic pitch fiber exhibits lower mechanical properties, such as strength and elastic modulus, compared to mesophase pitch fiber. However, it performs similarly in other aspects and is a general-purpose carbon fiber (GPCF) with a lower elastic modulus. Other Information on Carbon Fiber How Carbon Fiber is Produced Carbon fiber can be produced from either PAN-based carbon fiber or pitch-based carbon fiber, depending on the raw material. Flame-Proofing: Fibers are oxidized by heating at a temperature of 400~500°F in air to prevent melting in the subsequent process. Carbon Fiber: Heating at 1500-2900°F in an inert atmosphere removes hydrogen, nitrogen, and oxygen from the fiber. Graphitization: Graphitization of carbon by heating to 4,500~5,400℃ in an inert atmosphere to improve the modulus of elasticity. 1. PAN Carbon Fiber PAN-based carbon fiber is made from acrylic fiber (PAN fiber). In the flame retardant process, the acrylic fiber molecules are heated at 400-500°F in air to form a cyclic structure. In the carbonization process, the heat of 1,850°F or higher is applied in an inert gas to change the molecular structure of a crystalline carbon structure. Carbon fiber with high strength and high elastic modulus is produced at the end of the carbonization process. However, graphitization, in which a heat of 3,650°F or higher is applied, produces graphite fiber with slightly lower strength but high elastic modulus. 2. Pitch-Based Carbon Fiber Coal and petroleum pitches, which remain after distillation of tar obtained by dry distillation of coal and petroleum, are converted into fiber and sintered. Long fibers are made from the pitch in a melt-spinning process before the flame retardant process, and the precursor fiber is obtained by stabilizing the fibers. The precursor fiber is flame retarded, carbonized, and graphitized in the same manner as PAN carbon fiber to produce pitch-based carbon fiber. re write for blogChatGPT
Title: Unveiling the Marvels of Carbon Fiber: A Lightweight Powerhouse in Modern Manufacturing
Introduction: Carbon fiber, a remarkable material known for its exceptional strength-to-weight ratio, is a staple in various industries. This blog explores the production process, types, and diverse applications of carbon fiber, shedding light on its significance in fields ranging from aerospace to healthcare.
Production Process: Carbon fiber can be derived from either PAN-based or pitch-based sources. The process involves flame-proofing and subsequent heat treatments. Fibers are oxidized to prevent melting, followed by high-temperature sintering to eliminate hydrogen and nitrogen atoms, resulting in a carbon content of 90% or higher. Graphitization further enhances the modulus of elasticity.
- PAN-Based Carbon Fiber:
- Produced from polyacrylonitrile (PAN) fibers.
- Flame retardant process involves heating in air.
- Carbonization process at 1,850°F or higher in an inert gas.
- Optional graphitization at 3,650°F or higher for higher elastic modulus.
- Pitch-Based Carbon Fiber:
- Derived from coal or petroleum pitches.
- Melt-spinning process creates long fibers.
- Stabilization, flame retardation, carbonization, and graphitization processes mirror PAN-based methods.
- Offers adjustable modulus of elasticity.
Types of Carbon Fiber:
- PAN-Based Carbon Fiber:
- Mainstream, constituting 90% of global production.
- High strength and modulus.
- Widely used in aerospace, automotive, and sporting goods.
- Pitch-Based Carbon Fiber:
- Adjustable modulus of elasticity.
- Mesophase pitch for high performance, isotropic pitch for general use.
- Aerospace: Utilized in aircraft, rockets, and satellites for its lightweight and high strength.
- Automotive: Reduces vehicle weight, contributing to lower fuel consumption. Used in hoods, spoilers, and various components.
- Medical: Applied in surgical orthotics like artificial limbs due to its lightness and ease of handling.
- Sports and Leisure: Used in golf shafts, fishing rods, bicycle frames, tennis rackets, skis, and snowboards for strength and elasticity.
- Construction: Potential use in reinforcing concrete structures for earthquake resistance and as a substitute for cables and steel frames in suspension bridges.
Future Prospects: Carbon fiber’s future holds promise in construction and civil engineering, showcasing its potential in enhancing earthquake resistance and replacing traditional materials in infrastructure projects.
Conclusion: Carbon fiber stands as a testament to human ingenuity, revolutionizing industries with its unique combination of lightness and strength. As technology advances, the applications of carbon fiber are likely to expand, opening new frontiers in manufacturing and engineering.