The history of carbon fiber

Carbon fiber dates back to 1879. Inventor, Thomas Edison, used carbon fibers as filaments for early light bulbs (Hegde, 2004). Although these fibers lacked the tensile strength of today's carbon fibers, their considerable tolerance to heat made these fibers ideal for conducting electricity. Edison’s carbon fibers were made out of cellulose-based materials, such as cotton or bamboo, unlike the petroleum-based precursors used today. Carbonization took place by baking bamboo filaments at high temperatures in a controlled atmosphere. This is a method known as "pyrolysis," which is still used today. The resulting carbonized bamboo filaments were fire-resistant and capable of enduring the intense heat needed for incandescence.

It wasn't until the late 1950's that high tensile strength carbon fibers were discovered. Rayon became the first precursors used to create these modern fibers. Ultimately, it was replaced by more effective materials such as polyacrylonitrile (PAN) and pitch.

The benefits of these high-strength fibers were clear. They weighed a fraction of the weight of steel yet contained much greater tensile strength than steel. Another important benefit of carbon fiber was its high modulus, or resistance to stretching. This inelasticity plays an important role in reinforcing rigid structures such as the nose cones in hypersonic aircraft.

In recent decades, carbon fibers have found wide application in commercial and civilian aircraft, recreational, industrial, and transportation markets. Carbon fibers are used in composites with a lightweight matrix. Carbon fiber composites are ideally suited to applications where strength, stiffness, lower weight, and outstanding fatigue characteristics are critical requirements. They also can be used in the occasion where high temperature, chemical inertness and high damping are important. The suppliers of Advanced Composites Materials Association released 1997 industry statistics on worldwide shipments of carbon fibers for composites [1,2] (Table 1). However, from 1997 to 1999 there was a global slowing of carbon fiber demand [3]. According to Mitsubishi Rayon Co. Ltd. (Tokyo, Japan), a carbon fiber producer, worldwide consumption for sporting goods is nearly 11 million lb of carbon fiber

Table 1: Worldwide shipment of carbon fibers for composites

Year	Pounds
1992	13,000,812
1993	14,598,544
1994	17,425,452
1995	19,714,671
1996	20,672,741
1997	25,900,000

Currently, the United States of America uses nearly 60% of the world production of carbon fibers and the Japanese account for almost 50% of the world capacity for production. The largest producer of this fiber is Toray Industries of Japan. The world production capacity of pitch-based carbon fiber is almost totally based in Japan [4].

Table 2: Us composite Shipment in 1998

Market	Percent of total volume
Transportation	31.6
Construction	20.8
Corrosion- resistant	11.8
Marine	10.1
Electrical/Electronics	10.0
Consumers	6.3
Appliances/Business equipment	5.5
Aircraft	0.6
Others	3.3

REFERENCES

1. SACMA Releases “Carbon Fiber Industry Statistics”, Composites News, No. 1, 1998
2. SAMPE Plenary Describes “ Carbon Fiber Capacity, Trends”, Composites News, No. 6, 1998
3. Carbon fibers Seen as Having Big Long Term Growth Infrastructure is Next Big Trend Driver, “Advanced Materials & Composites” News, No. 3, 1999
4. Composites Edge; 1992
5. US5536486, “Carbon fibers and Nonwoven Fabrics“
6. Rehabilitation Bridges: Carbon Fiber-reinforced Polymer Shows Promise for Repairing
7. Structures, Advanced Materials & Composites News, No. 2, 1999
8. New Company Launches Carbon Fiber Fabrics for Decorative Applications, Advanced
9. Materials & Composites News, No. 8, 1998
10. Carbon fibers Electrical Conductivity Found to Offer New Uses, Composites News, No. 3, 1998 9Jean-Baptiste Donnet, Roop Chand Bansal, “ Carbon
11. “Fibers”, published by Marcel Dekker Inc., 1990, p370.