Is CFRP overrated or Why do we use it

Carbon fiber become so common in many products that it lost its magic for me. It is used in many products that its properties are not necessary. I do not want to see another product with irrelevant CFRP on it. It has excellent properties but probably most users do not even know what it is good for. Here is a short article about its properties:

It is not the material of choice in many applications for solely its strength. Also there are many better materials than it at many applications (well excluding price, if we take price into account it can rarely be used, as it is now).
By the way, I do not want a watch with a CFRP face, a car with CFRP dash or any other non-structural place. I still love a car with CFRP chassis, or a bike or a knife with CFRP handle, where CFRP does what it should.

You didn’t even get into the faux ‘carbon fiber’ decals, applied to many of the products you mentioned!

Its hard to pin down exactly when a raw, black woven fabric became synonymous with the appearance of performance, to the relative detriment of more honest materials. My titanium bike gets less looks than the latest swoopy carbon frame, and the carbon fairings on my moto look like ass due to the UV breaking down the resin.

Is it over-rated? Absolutely. But check this: “wheel set and mudguards made from aluminum glass fiber coated carbon composite”

Good article posting by the way.

Reading about carbon fiber today reminds me of reading about fiberglass in the 1960’s. Sure, there are great applications, but we shouldn’t toss out our old materials without balancing the real needs and costs.

My favorite Carbon Fiber application to date was a student project for - I kid you not - a sh*t bucket. Literally a wheel barrow for carting around horse manure. The girl designed the entire thing out of “carbon fiber” and when asked why said “Because it’s light and durable”.

I couldn’t help but shout out “so is plastic”

I wouldn’t say it’s “overrated,” it’s just often inappropriately used. There is no better material when you need something strong and stiff, and when weight is your major constraint, and cost isn’t. So airplanes, race cars, road cars in some applications, bicycles, laptops, are all good places for it. Desk accessories and toilets are not.

With RTM and short strand injection molding, the cost is coming way down, so you’re only going to see more of it.


It also seems to be tailored a bit to a certain demographic. Like you mentioned, the main applications (or the ones that make sense anyways) are for transportation. I’ve seen race-heads go nutso for CF…like crazy nuts…

They get excited when they see faux CF on a button or a wallet (even shirt prints…). It’s almost like now they’re able to live just like their favorite racers or something…It’s definitely a mindset for a lot of people.

I am not trying to defend the overuse of Carbon fiber here. I’m just saying that it does add a nice texture detail to a product.

@Cyberdemon, seriously, the carbon fiber “shit barrow” was awesome. I NEED one.

Low weight or low density of a material is not the key to lightweight design. When the topic is on materials (there are other options, e.g. stress-related engineering/design), the real question is:
What specific yield strength Rp0,2/(ρg) or specific E-modulus E/(ρg) values can the material provide?
For bending, torsion and pressure load, the I/A and W/A ratios of the used profile sections are also important.
You have to determine the loads on the structure and you have to decide whether a high maximum load or a minimum elastic strain is the major constraint. After that, you can make a reasonable choice of the right materials for your specific use :sunglasses:
You also have to be carefull no to weaken the structure due to inappropriate joining locations.
Someone who says: “CFRP is an excellent material for lightweight design” just proves he has no clue what he’s doing :confused:
CFRP is an option when you need a high specific yield strenght and can accept high elastic strain (much higher than aluminium or steel). You have to consider that CFRP is difficult to work and fragile. Even small bubbles or cracks can cause a CFRP structure to fail.

gold is over rated, but these exotic materials just has sex appeal so it sells.

At least, by using gold you make no attempt to create a pseudo-lightweight look :laughing:

yeah, and it’s not like people are making things out of fake gold, I mean can you imagine…fake gold???

oh wait…

As with most things, it comes down to context and application, when applied correctly in the right context, Great.

Yes, for the interior of chinese restaurants, fake gold is as appropriate as CFRP for fake lightweight design :stuck_out_tongue:

So I am not alone thinking like this. Even big manufacturers use CFRP for just its appearance.

Titanium does not have such fake usage as far as I see. It has great properties, it is the material of choice in many applications. Half of F-22 is made of titanium alloys, I think this one example is enough to show how great it is. It also has a distinctive look too. However it is used where ever it is appropriate. Hmmm.

Hehe, it’s harder to impress a connoisseur than “John Doe”.

Titanium isn’t as faked or used improperly because most people won’t be able to tell the difference between different metals. Where people know how carbon fiber, gold, diamonds, gems, chrome, silver, (or what ever else) looks like so they are more commonly used (and faked) as an aesthetic trim rather than function to “increase” the quality of perception of that product.

@nicanor: That’s the point. Exactly.

If anything, titanium has less of a ‘sheen’ than other metal materials. The dull warm gray doesn’t have an inherent bling that is readily apparent. That’s why I think its cool - when you see it, 99% of the time its needed.

The only carbon fiber I encounter daily is in bike products, although I’ve seen fancy S4 dash boards with carbon overlays. Utterly useless!

Here’s a 2.7kg (5.95 lbs) bike - couldn’t have gotten there with anything but refined petroleum products…

It looks like even Apple is getting into it now.

They could build their freekin’ product from duranium or tritanium and power it up with a warp core and I still won’t buy it because there’s no reasonable use for it.

I’ll wager $0.77 that the new iPad doesn’t use CF. Pointless, not suited for the application, and goes against their ‘green’ story.

Unless of course they invent some new process or material and have us all flabbergasted and needing to incorporate it in our design work immediately.