Carbon fiber (CF), also known as graphite fiber, is a polymer that has a chemical structure of a long bonding chain of carbon atoms. Carbon fiber is a lightweight material and is thinner than a strand of human hair that has a diameter of about 5 to 10 micrometers. However, it offers high tensile strength and high stiffness. Owing to excellent properties such as high chemical and temperature resistance and low thermal expansion, CF is widely used by several high end-users including aerospace, military & defense, automotive, and motorsports industries.
One key advantage of CF is that the materials can be manufactured and shaped according to specific requirements. For instance, when several CF are combined, it becomes extremely strong and can be produced as a yarn, which can be further woven to produce a fabric. However, the relatively high cost of the CF materials as compared with other types of fibers such as plastic or glass fibers remains a key disadvantage of the fiber material.
These fiber materials or fabric are normally combined with other polymers to form various composite materials. Carbon fiber reinforced plastic (CFRP) is a composite material that uses carbon fibers, as the principal structural component and is produced by mixing carbon fiber with a plastic resin. This combination of reinforcing carbons and a polymer matrix leads to high-performance materials and provides a highly effective strength-to-weight ratio. These composite materials offer high-temperature tolerance and high tensile strength that have a wide range of applications across several industries.
Classification and Manufacturing of Carbon Fiber
The classification of CF is mainly based on the tensile modulus of the fiber, which is broadly categorized into low modulus, standard modulus, intermediate modulus, high modulus, and ultrahigh modulus. CF offers a tensile modulus below 34.8 million psi (240 million kPa), which comes under the category of low modulus, while the ultrahigh modulus carbon fibers have a tensile modulus of 72.5 -145.0 million psi (500 million-1.0 billion kPa). However, the strongest carbon fibers are ten times stronger than steel and eight times that of aluminum, and also are much lighter compared to both materials, nearly 5 and 1.5 times respectively.
The process for making carbon fibers is called carbonization, which is conducted with the support of both chemical and mechanical instructions. Carbonization is a process to extract a fiber composed of long and tightly interlocked chains of carbon atoms, with a little presence of non-carbon atoms in the fiber. The process is conducted using a very high heat temperature without the contact of oxygen and the high temperature expels all non-carbon atoms present in the fibers. During the process, a variety of gases and liquids are used to achieve a special effect, which either acts to prevent certain chemical reactions with the fiber or to initiate a particular reaction with the fiber.
In this process, three types of raw materials, shortly called the precursor, namely polyacrylonitrile carbon fibers (PAN-based CF), pitch-based carbon fiber, and rayon-based carbon fiber are used to produce CF. The PAN-based CF is the most popular raw material and nearly 90% of the carbon fibers produced are made from polyacrylonitrile (PAN), while the rest 10% are made from using either rayon or petroleum pitch. These three materials are organic polymers having a long chain of molecules forged together by carbon atoms but the composition of each precursor is different from one manufacturer to another.
History and Development of Carbon Fiber
The first development of carbon fiber can be traced back to the mid-19th century, when an English scientist, Joseph Swan developed a carbon filament for his light bulb. Swan improved his carbon filament by treating carbon fibers with another acid to achieve highly effective solutions. Using cotton threads in the carbonization was started by Thomas Edison, which paved the way to supply the first incandescent light bulbs used to illuminate using electricity.
The wide expansion of research on carbon fiber can be seen in the late 1950s with the introduction of high-performance fibers by an American physicist, Roger Bacon. The carbonization process of carbon fiber was conducted using heating strands of rayon but was found ineffective as it contained only about 20% carbon. The mass expansion in the production of carbon fiber wad was made possible in the early 1960s after a Japanese scientist started using polyacrylonitrile (PAN) as a raw material in carbon fiber production, which contained a high level of carbon atoms. Later, many scientists have started developing several high ended-carbon content fibers that contained nearly 99% using rayon or petroleum resin as a precursor. These fibers provided high strength in terms of tensile and elasticity module, high-temperature tolerance being light weighted at the same time.
Till the 1990s, the UK and Japanese manufacturers dominated the carbon fiber market with the leading companies such as Courtaulds (UK) and Toray, Nippon Carbon, Toho Rayon, and Mitsubishi (Japanese). CF produced from these companies was widely used in various aerospace applications by giving priority to defense and military equipment. With the rising adoption of CF by companies such as McDonnell Douglas, Boeing, Airbus, and United Aircraft Corporation, the application was expanded to civil aircraft manufacturing later on. Today, CF is widely used in the production of various equipment such as wind turbines, automobiles, and sporting goods applications.
Key Industries of CF
The major consumer of CF is the aerospace & defense industry due to the rising huge spending from countries both from developed and developing regions for modernization and upgrading of their existing air defense vehicles and equipment. Moreover, the rapid growth of commercial aircraft or passenger airlines across the globe, despite the trend was skewed substantially during the last month of 2019 till now due to the COVID-19 outbreak, is expected to increase the demand for CF in the industry in the coming years.
Demand for CF and carbon fiber reinforced plastic are growing at a healthy rate due to the wide adoption of the materials for the production of vehicle components. Factors such as eco-friendly substances, high tensile strength, and impact resistance, the materials are widely used in the automotive industry especially in the manufacturing of top-end sports cars that require strong and light material. On top of that, the materials are ideal for overall vehicles as they offer fuel-efficiency factor and reliable performance.
Wind Energy Industry
Wind energy is one of the fast-growing industries and the global shift to a renewable source of energy solutions present a key driving factor for the growth of the industry. The materials of CF and CFRP are widely used in the manufacturing of several components of wind energy systems such as wind turbines and engines.
As per the recent report published by Growth Market Reports (GMR), the global carbon fiber market was valued at USD 3,340.5 million in 2019 and is projected to reach USD 6,935.9 million by 2027, expanding at a CAGR of 9.6% during the forecast period.
The global carbon fiber & carbon fiber reinforced plastic market is segmented into raw materials types, resin types, applications, sales channels, and regions. The raw materials types include polyacrylonitrile carbon fibers (PAN-based CF), pitch-based carbon fiber, and rayon-based carbon fiber. The resin types consist of thermosetting CFRP and thermoplastic CFRP. In terms of applications, the market is divided into aerospace & defense, sports & leisure, wind energy, automotive, pressure vessels, construction & infrastructure, chemical, oil & gas, and others. The sales channel is further bifurcated into manufacturers and distributors. The market is widely expanded over five key regions, namely North America, Latin America, Europe, Asia Pacific, and Middle East & Africa. North America is a promising region for the market. Growing research and development activities in the aerospace and defense sector in the US is expected to boost the demand for CF and CFRP during the forecast period.
Some of the key players in the market include TEIJIN LIMITED, Formosa Plastics Corporation, Hexcel Corporation, TORAY INDUSTRIES, INC., and others. These companies are considered to be key manufacturers of the market on the basis of product availability, regional presence, better supply chain management system, and the increasing demand for the products. The majority of them are actively engaged in the adoption of several market strategies such as acquisition, and geographical expansion to enhance their presence in the carbon fiber & carbon fiber reinforced plastic extraction. Some of the key market strategies are listed below:
- On December 19, 2017, SGL Carbon completed the purchase of 50% shares of BENTELER Carbon Composites Beteiligungs-GmbH in the joint venture Benteler SGL GmbH & Co. KG, Paderborn. The transaction resulted in SGL Carbon being the sole owner of the company, thus strengthening its production capabilities for components produced from fiber-reinforced composites.
- On December 3, 2019, Solvay and SGL Carbon entered into a joint development agreement (JDA) to commercialize composite materials based on large-tow intermediate modulus (IM) carbon fiber. This agreement has helped Solvay strengthen its hold in the aerospace industry.
Being an environment-friendly product, the market of CF and CFRP has a wide range of lucrative opportunities to grow in the coming years. Strict regulations regarding the implementation of environmental standards across the globe especially in developed countries prove to be a key aspect that can push the market at a significant pace.