What Is Carbon Fiber, Exactly?

Carbon fiber is a polymer, also known as graphite fiber. It is strong and lightweight—five times stronger than steel and twice as stiff. Though carbon fiber is stronger, lighter, and stiffer than steel, making it ideal for many parts, there are many other reasons why engineers and designers favor carbon fiber for manufacturing.

Carbon fiber is a material that is made from thin, strong filaments of carbon. Each filament can be thinner than a strand of human hair and gets its strength when twisted together like yarn. Then it can be woven together to form cloth, and if needed to take a permanent shape, carbon fiber can be laid over a mold and coated in resin or plastic.

As well as being strong, Carbon Fiber is:

Is high in stiffness
Is high in tensile strength
Has a low weight-to-strength ratio
Is high in chemical resistance
Is temperature tolerant to excessive heat
Has low thermal expansion

Due to these characteristics, carbon fiber is used widely in many industries, including aerospace, automotive, military, and recreational applications.

What Is Carbon Fiber, Exactly?

A Short History of Carbon Fiber

Carbon fiber dates back to 1879 when Thomas Edison carbonized cotton threads and bamboo silvers at high temperatures. By 1958, high-performance carbon fibers were invented just outside of Cleveland, OH. Although they were inefficient, these fibers contained around 20% carbon and had low strength and stiffness properties.

In 1963 a new manufacturing process was developed at a British research center, and this led to the discovery of carbon fiber's strength potential.

How Carbon Fiber Is Made?

A Quick Look at the Carbon Fiber Manufacturing Process:

Carbon fiber is made by drawing long strands of carbon fibers, heating them to a very high temperature without allowing contact to oxygen to prevent burning, and then carbonizing the fibers. Carbonization is a process by which the atoms inside of the fibers vibrate violently, expelling most of the non-carbon atoms. This leaves behind a fiber composed of long, tightly interlocked chains of carbon atoms with only a few non-carbon atoms remaining.

What Is Carbon Fiber, Exactly?

A typical sequence for making carbon fibers from polyacrylonitrile involves spinning, stabilizing to make the fibers more durable, carbonizing, treating the surface, and sizing.

What Can Carbon Fiber Be Used For?

We can make just about anything out of carbon fiber. If you want a carbon fiber pint glass, that's no problem. We've made many different shapes with both composite and aluminum materials, including:

Bike frames
Aircraft Wings
Automotive drive shafts
Tubing
Containers
Propeller blades
Car components

According to the Energy Department's website, an article at energy.gov, carbon fiber composites could reduce a passenger car's weight by 50%, thereby improving its fuel efficiency by nearly 35% without compromising either its performance or the safety of its passengers.

What Is Carbon Fiber, Exactly?

Here are some frequently asked questions about carbon fiber:

1. Is Carbon Fiber metal or plastic?

Carbon fiber is a polymer—that is, it's made of long chains of molecules that are bonded together. It's also sometimes called graphite fiber because it's made of carbon atoms and the same substance found in pencil lead. Carbon fiber is very strong and very lightweight, so it's used in many different ways, from aerospace parts to golf club shafts. It's five times stronger than steel, yet twice as stiff!

2. What is the price of Carbon Fiber?

The price of aerospace-grade carbon fiber currently ranges from $80 to $120 per pound. In other industrial, sporting goods, and wind energy applications, the price ranges from $10 to $20 per pound.

3. Why is Carbon Fiber used in cars?

Carbon fiber is a stronger material than steel but is also lighter. In the auto world, it's ideal because it lowers the vehicle's weight while still being able to withstand the stresses of racing at high speeds. For many years now, supercars and even some expensive sports cars use carbon fiber as a primary build material.

4. Does Carbon Fiber crack easily?

Yes! That's because carbon fiber has an incredible stiffness-to-weight ratio but is quite brittle and prone to splitting or cracking.

5. Is Carbon Fiber harmful to humans?

However, we do know that inhaling carbon fiber dust is harmful. Exposure to dust can cause lung cancer, mesothelioma, and asbestosis. Just because it might not be as bad as asbestos doesn't mean that it's safe. However, the known potential health risks are severe enough to warrant protection.

6. Does Carbon Fiber melt with fire?

Carbon fiber is so stable that it would be tough to burn it. If heated to 750 degrees, it will burn slowly as long as a burning fuel source is applied to it. But even at this point, the fire will go out as soon as the fuel source is removed.