Take you to understand the interesting story behind carbon fiber

1.How fine is the carbon fiber?

How thin is carbon fiber? In fact, the answer is very simple, the diameter of carbon fiber is between 5 and 10 microns. Speaking of which, it's kind of hard to imagine, right? So, let's compare them to something all humans have - hair! Fortunately, there's a really nice picture below that makes it easy to compare the two. This will make you realize how thin carbon fiber really is, a human hair is about 40-120 microns in diameter.

If you think that human hair is a very fragile material, you are wrong! It consists almost entirely of a protein called keratin, which has an ultimate tensile strength of about half that of steel (200MPa). If you were testing the tension on a single rope, you would only be able to measure about 100 grams of force.

Coming back to carbon fiber, the small diameter is critical as it enables higher graphite content. In this way, the probability of defect concentration in the 3D structure is greatly reduced. Generally speaking, the mechanical properties of carbon fibers are inversely proportional to their filament diameter.

2. What was the first application of carbon fiber?

 

In fact, carbon fiber is older than you might think! The first carbon fiber dates back to 1860! And in 1879, a man named Thomas Edison chose carbon fiber to make light bulb filaments.

At the time, they were not oil-based. Instead, they are produced by the pyrolysis of cotton or bamboo silk. These filaments are heat treated at high temperature to achieve carbonization.

But why were they chosen? The answer is simple, it has nothing to do with high intensity! At the time, Edison noticed that their high heat resistance made them ideal conductors of electricity. Before long, however, tungsten filament became the preferred choice for light bulb filaments in the early 20th century, and carbon fiber was phased out over the next 50 or so years.

In the 1960s, a Japanese researcher named Akio Shindo successfully used polyacrylonitrile (PAN) as a precursor to make carbon fibers. In this way, his team was able to produce filaments with a carbon content of about 55 percent using a more cost-effective production method. This new technology has brought a revival to carbon fibers, but this time, they're here to stay!

 

2. When was the first carbon fiber bike born?

 

Like any sport, competition for the best tends to lead to any possible innovation, and as all composite enthusiasts know, carbon fiber can always help make that happen!

The first full-carbon commercial production bike was the most iconic Kestrel 4000, which was released in 1986. Previously, the bike industry's use of carbon fiber was limited to gluing carbon fiber tubes to aluminum lugs.

The 1989 Tour de France kicked off the carbon fiber revolution. Over the next decade, metal bikes continued to feature heavily on the circuit, but with declining success rates.

The last time I won a Tour Championship with a steel bike was in 1994, and the last time I won a race with a non-carbon fiber bike (this time made of aluminum) was in 1998.

Carbon fiber composites allow for further weight benefits as well as more aerodynamic shapes that metal can't do!

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