Stronger than steel and a fraction of the weight, carbon fiber is a brilliant invention. Has been for decades. Junior Johnson was building rule-bending Nascar racers out of the stuff back in the '80s. But even with all that time to come up with new sourcing and production methods, carbon fiber just won't stop being expensive. The cheapest new car with a carbon-fiber tub, the Alfa Romeo 4C, is sized for Stuart Little, yet costs as much as a Mercedes E-Class. And the real chariots of the carbon gods, the McLarens and Koenigseggs and Lamborghini Aventadors of the world, are strictly six-figure propositions. We still haven't managed to mass-produce the stuff at anything approaching the price of aluminum, let alone steel. Why hasn't anyone figured out how to make this stuff cost less?
That question is why I'm here in Sant'Agata Bolognese, Italy, at Lamborghini's carbon-fiber facility, laboriously squeegeeing air bubbles out of a sheet of carbon weave. I want to ask the guys in (black) lab coats who make this material: Why aren't we rolling around in carbon-monocoque Hyundais?
Carbon vs. Steel
In 2017, to create the metal components at the core of most cars, you pour your super-hot liquid aluminum or steel or magnesium in a mold, and cast it. You can smash it into shape, you can carve it with a CNC machine, you can weld pieces together. You've got options, all of them reasonably speedy and affordable. To make a part out of carbon fiber . . . well, first you get the raw material out of the freezer.
The glossy woven rolls of carbon fiber, filled with resin (called pre-preg) and backed with adhesive, are stored at zero degrees Fahrenheit. Any warmer and the resin will harden. That temperature sensitivity also means you can't cut the material into shape with a CNC laser—to keep it cool and malleable, you need to use a blade, which eventually wears out. Even then, the clock is ticking. From the time the first weave of these plastic carbon threads is cut, you have about a day to shape it.
So you make haste with the plastic spatulas and force the black and silver sheets into a mold, which will be good for only about 300 uses before it's deformed and gets trashed. Piera, the woman tasked with explaining all this to me, seems flummoxed at my plodding pace. She produces a hair dryer and heats the material to make it more pliable. But of course, you don't want too much heat, lest your pre-preg prematurely calcify into the wrong shape.
Futuristic but Handcrafted
About a decade ago, I visited another one of Lamborghini's plants. I watched a woman lovingly stitch the seats on a Murciélago, practicing a brand of methodical craftsmanship that would be too laborious, too inefficient for a mass-market car. Now, here I am again, witnessing a similar degree of manual artistry invested in the creation of a material that we think of as far more futuristic. I mean, you'd expect that Lamborghini's leather was stitched by hand. But those aerospace-looking wings and spats, the big carbon tub at the heart of the Aventador? It all looks like it was reverse-engineered from a captured extraterrestrial landing craft, not handmade by an Italian woman named Piera. And yet, this is still the most economical way to produce carbon fiber. On a small scale, anyway.
"If I have to do ten parts, handmade is still the best way," says Luciano De Oto, head of Lamborghini's Advanced Composite Research Center. "Above 2,000 parts, I need to increase automation and use chopped fiber." That would be "forged" carbon fiber, but we'll get to that. First, I've got to vacuum-bag my part.
To ensure that the first layer of carbon fiber conforms to the mold, I seal the sheet in plastic and suck out any air pockets between layers. Then, I cover that with heavier cloth before placing the whole thing inside another thicker plastic vacuum bag, the sort you'd use to shrink down your duvet for summer storage. After removing trapped air, we set four more layers, then one more vacuum routine after the final layer. It's tedious. Companies like BMW are building robotic production lines to do this faster than humans. But even then, it's slow.
Besides being time-intensive, the carbon-fiber manufacturing process is also an energy hog. The storage freezers and occasional blast with the hair dryer are minor compared to the autoclave, a pressurized oven used to cure finished parts. My particular hunk of hand-laid goodness will bake in the oven for six hours at nearly 400 degrees, all while under six times the normal atmospheric pressure. At least Lamborghini has a 1.2-megawatt photoelectric solar array on the roof of the factory.
A Mass-Production Solution
While my componentcures, I head over to the area where Lamborghini makes forged parts. Instead of the neatly woven pre-preg I worked with earlier, machines here use a rough carbon fiber known as chopped mat. A square of this material is pressed into basic shapes over a mold, then moved into the eight-piston forge, which applies 300 degrees of heat and 2,900 psi of pressure. Unlike pre-preg, chopped mat can be smashed into exotic shapes—screw anchors, thin ridges—that aren't possible when you're hand-wrapping fabric. The process is mostly automated, and in 20 minutes we'll have the same part that still needs about five more hours in the autoclave.
A forged product isn't as light or strong as the hand-laid stuff, but if carbon fiber is ever going to go mainstream, this looks like the way. "Diamonds have a higher cost than gold," De Oto says. "Hand-laid carbon fiber won't achieve the cost of aluminum, but in the next ten years, chopped mat might." Even if cars just get the chopped-mat carbon fiber, as on the BMW i3, that's still a huge upgrade from aluminum. Lighter, more mpg, and no lost safety.
But the sophisticated hand-laid stuff, with its freezers and autoclaves, vacuum bags and squeegees and fragile molds? That will always be an exotic material for exotic cars. Lamborghini needs three weeks to produce each Aventador body-in-white. That pace is never gonna fly at the Accord plant in Ohio.
By 17:00, the factory is clearing out, and I join the workers in black lab coats flowing through the gate. I never do see the part that I made. It's still in the autoclave, and I don't have time to wait.
Thomas Edison made carbon fibers out of bamboo and cotton, using them as filaments in lightbulbs.
Boeing can repair minor damage to the 787's carbon composites at the gate, in less than an hour.
About 70 percent of carbon fiber is produced by Japan.
Dumbest thing made out of carbon fiber: the carbon-fiber fedora.
The Flying Doctors
When an Aventador crashes, Lamborghini sends out the Flying Doctors, technicians trained to repair carbon-fiber parts. The team keeps six oversize steamer trunks with ultrasound equipment and portable curing machines strategically positioned around the world. Why not check it with their luggage? "Customs doesn't like to deal with chemicals," says Casper Steenbergen, head of carbon-fiber materials repair. Besides, no need for additional delays. "We had to make new jigs for a whole rocker-panel section for a car in China," he says. "That repair took two weeks." Technicians excise the damaged section and rebuild, layer by layer, until the carbon fiber is certified to the original spec. In fact, Lamborghini wrote the standard, ISO 17065, which means that Ferrari has to follow Lamborghini's rules to certify the repair of a broken Enzo. And yes, the Flying Doctors do seem to get a kick out of that.
This story appears in the March 2017 Popular Mechanics.