Go into any manufacturing facility and you are likely to see one of the following four materials in abundance: aluminum, steel, petroleum-based plastics, and wood. Carbon fiber is starting to show up here and there, but not nearly as often as the other four materials.
So, will carbon fiber ever rule the manufacturing world? A carbon fiber evangelist would likely say ‘yes’. But step back and look at it a bit more realistically and it is hard to conclude that carbon fiber will ever become the de facto replacement for the other four dominant materials.
This is not to say that carbon fiber is inherently inferior to aluminum, steel, plastics, and wood. Quite to the contrary, it is superior in most areas of performance and integrity. But the one thing all those other materials have going for them is cost. Compared to carbon fiber, they are extremely cheap to work with.
Manual Layups with Prepregs
To understand why the cost of carbon fiber is so prohibitive, look no further than a February 2017 article published by Popular Mechanics. The author of the article, Ezra Dyer, paid a visit to one of Lamborghini’s facilities in Italy. He discovered quite quickly why the world isn’t driving around in carbon fiber Kias.
One of the first things Dyer did was learn about the manual layup process. When Lamborghini engineers need only a small number of parts, they make them manually by layering multiple sheets of carbon fiber fabric, known as prepregs, into a mold.
As a side note, Utah-based Rock West Composites explains that prepregs are sheets of carbon fiber fabric that come already impregnated with epoxy resin right from the factory. Techs use them for manual layups that require a bit more precision along with even epoxy saturation.
Anyway, getting back to Dyer, he learned how to do a manual layup using a mold and prepregs. His finished layup went into a high-heat autoclave for five hours of curing. Dyer soon figured out that the combination of time and labor would make the parts he helped produce quite expensive.
Chopped Mat Carbon Fiber
After learning all about the manual layup process, Dyer was introduced to the concept of creating forged parts from a product known as chopped map carbon fiber. Unlike prepregs made with virgin carbon fiber fabric, chopped mat is a recycled product.
Shredded carbon fiber parts are used to create the chopped map material, a material that can be pressed into molds using a forge that applies both high heat and pressure to create parts in just about every size and shape. Those parts also spend time in the autoclave after forging.
Because forging can be automated, Lamborghini uses it to produce high-volume parts. It is faster, cheaper, and more flexible than manual layups. Lamborghini doesn’t sacrifice any safety with forged parts, but they do sacrifice some weight.
Cannot Compete on Cost
At the conclusion of his time in Italy, Dyer was clear in his understanding that carbon fiber cannot yet compete with aluminum, steel, and other materials based solely on cost. So for manufacturers, the question is one of cost versus benefit. Is it worth it to them to embrace carbon fiber over their other materials, or does the added benefit of carbon fiber not justify its higher cost?
Answering that question will ultimately determine whether carbon fiber ever rules the manufacturing world. In all likelihood, it will not. Carbon fiber will continue to be an attractive option for certain kinds of applications, but the other four materials are not going away.