Is Carbon Fiber Going Mainstream? 152
cartechboy (2660665) writes "To date, carbon fiber has been expensive and presents different production challenges than traditional steel and aluminum. But now it seems as if the advanced material is about to become truly mainstream--BMW has announced it plans to triple carbon fiber reinforced plastic output at its Moses Lake facility in Washington state. Currently, the SGL Group plant, a joint venture partner of BMW Group, has the production capacity for about 3,000 tons of carbon fiber per annum. Two productions lines are currently going with the output dedicated to BMW's i3 and i8 plug-in vehicles. SGL is already working on a third and fourth production line which would double production to 6,000 tons per year, but a fifth and sixth are on the way, set to triple capacity to 9,000 tons every year. This extra output won't be reserved exclusively for BMW's i range. Several future BMW models will make use of the lightweight material. Now the only question is how long before carbon fiber vehicle construction becomes as common as aluminum?"
CF in Cars (Score:5, Informative)
BMW has already been putting CF into weight-sensitive areas of the car, like the roof panels on certain models. Up high is one of the worst places to carry weight from a vehicle dynamics perspective; it makes nearly every aspect of vehicle handling worse.
One practical difficulty of CF for general automotive use is that it's not really repairable.
Of course, modern autobody repair is often about replacing affected panels with pristine replacements (either new or from junk yard cars), as opposed to trying to repair an existing panel. So, in that sense, CF might be a fine choice, as the lack of reparability is in practice a non-issue.
BMW is already gluing cars together -- for almost 10 years they have been building the front clip on certain models out of aluminum, and in effect gluing it to the remainder of the unibody, which is conventional steel.
Also, BMW has been designing recyclability into its cars also for at least 15 years. I seem to recall that the E46 3 series was something like 90% recoverable.
I don't expect they would turn away from their recyclability commitment, so they must have a plausible plan for how they would like to apply it to CF parts.
Re:Recycling (Score:5, Informative)
We went through this exact thing with bicycle frames about 10 years ago. CF is lighter and more rigid than aluminum, but if it gets a crack or gouge in it, the frame can't be mended... it has to be tossed, and the only real way to "recycle" CF is to toss it into a thermal depolymerization machine and "boil" the epoxy and CF (using lots of water and heat) back to crude oil.
CF has its place, but on a vehicle where weight is less a limiting issue than on bicycles, it might be best off to stick with recyclable stuff like aluminum because of the volume of vehicles made. Aluminum can be recycled fairly easily... CF can't be used for much once it hits the scrapyard.