The first carbon fibers
The synthetic carbon industry had its official beginning in 1886 with
the creation of the National Carbon Company. Based in Cleveland, Ohio,
the company would eventually merge with Union Carbide in 1917 to form
Union Carbide & Carbon Corp., which changed its name to Union Carbide
Corp. in 1957.
Electricity was mostly a lab curiosity until the late 1800s, when carbon
arc lamps began lighting the streets of major U.S. cities. The lamps were
composed of two carbon rods connected to a current source and separated
by a short distance. A blazing hot path of charged particles — the
“arc” — formed between the two rods, giving off an intense
light. National Carbon got its start by producing carbon electrodes for
streetlamps in downtown Cleveland.
In 1879, Thomas Edison invented the first incandescent light bulb, which
uses electricity to heat a thin strip of material, called a filament,
until it glows. He may also have created the first commercial carbon fiber.
To make his early filaments, Edison formed cotton threads or bamboo slivers
— into the proper size and shape — and then baked them at
high temperatures. Cotton and bamboo consist mostly of cellulose, a natural
linear polymer made of repeating units of glucose. When heated, the filament
was “carbonized,” becoming a true carbon copy of the starting
material — an all-carbon fiber with the same exact shape. Tungsten
wire soon displaced these carbon filaments, but they were still used on
U.S. Navy ships as late as 1960 because they withstood ship vibrations
better than tungsten.
Near the end of World War II, Union Carbide began investigating a replacement
for tungsten wire in vacuum tubes by carbonizing rayon — another
cellulose-based polymer, like cotton, that became popular in clothing.
The end of the war brought an end to the government’s funding for
this project, but carbon fibers were still raising interest in the commercial
sector. Barnebey-Cheney Company, in 1957, briefly manufactured carbon
fiber mats and tows (rope-like threads without the twists) from rayon
and cotton. These were used as high temperature insulation and filters
for corrosive compounds. A year later, Union Carbide developed a carbonized
rayon cloth and submitted it to the U.S. Air Force as a replacement for
fiberglass in rocket nozzle exit cones and re-entry heat shields.
While finding a certain degree of success in their respective niches,
all of these early carbon fiber materials had poor mechanical properties,
making them unsuitable for structural use. It took a chance discovery
to set the age of high performance carbon fibers in motion.