Is CFRP overrated or Why do we use it

Same here

There seldomly is a real need for new materials. Many CFRP products could have been made from modern steel alloys as well, without making them heavier or weaker but surely cheaper.
And apple should stop its development of pure consuming frontends, which in some way behave like parking meters. When I think back, as a kid in the early 90s, when I was playing with a gameboy, the limitations were obvious and I quickly realized that there are also real computers to create your own stuff on. Apple re-intruduces the gameboy’s limitations again, but now it’s harder for the up-growing generation to get the idea that there has to be more than that.

I believe there is always a real need for new materials. New materials are not necessarily life CFRP, new can be cheaper, environmentally friendly, stronger, tougher etc. A better material always can improve many things. But if they are used properly.
And I again agree with gameboy limitation stuff. I think it is like fashion. People just follow. Most don’t even consider other options.

Just saw this hot mess on the new A3 sedan concept:

Check this watch:

It is from a very high-end company and has a CFRP case. The point is the case is made by stirring Carbon fiber vigorously in a cup and molding it to a shape. So it is made of a random bundle of Carbon fibers, and this way carbon fiber cannot provide any strength in traverse directions i.e. directions perpendicular to the flow direction. It is basically not different from a epoxy case in terms of strength. They even call the process Carbon Forging. Carbon cannot be forged, it is completelt irrelevant. There are many ways to make a CFRP case utilising the strength of CFRP, and I have seen no watch that uses any of those methods. Actually I highly doubt that the watch compaines want to utilize the properties of CFRP other than its looks. If they make a proper case it would be too light, and lightness resembles cheapness in watch world.

Hmm maybe I shall start producing proper CFRP cases. Does anyone have connections with Swiss watch industry?

Aren’t the fibers in glass-reinforced nylon arranged in a similar way? Seems like it must offer some strength improvement.

There are many kinds of composites. Relevant to this topic, there is particle reinforced composites, whisker reinforced composites, short fiber reinforced composites, continous fiber reinforced composites. Particles are basically dust, whisker is a very short rod with and aspect ratio of say 10. Short fibers are a few mm to cm long fibers, continous is trivial. As you see from the first one the lenngth of the fiber gets longer. So does strength, and stiffness. Former ones are used as they are cheap and easy to produced. They are also rather isotropic, i.e. their properties are the same in every direction. When you want top notch performance (like you do when you pay a watch some 30+ K USD) there is one choice, continuous fibers. But their properties vary on the direction, and you need to lay the fibers carefully in alternating directions, based on calculations, to get the best performance. This makes them hard to produce, labor intensive etc.

Glass-reinforced nylon is cheap and strong, but here customer pays enough mony to buy a CFRP race car chassis, but gets this. Sure it provides some reinforcment, but nowhere near what we would expect.

You think this wrong just because you don’t understand the benefit of it use in this application. Perhaps if you had knowledge of the situation your narrow mindedness wouldn’t show through so well.

I use a “sht bucket" everyday, not only for horses, but pigs and cows. A carbon fiber wheelbarrow capable of holding 200 liters would be noticeably lighter than one made out of plastic. The real question is if the container is the best place to utilize carbon fiber on such a "Sht bucket”. The wheel rims and basic frame would be a better application, as the tines of the pitchfork used to transfer the waste to the wheelbarrow would easily destroy the carbon fiber. But, if it were a composite of carbon fiber coated with a polymer, it would be just as durable and much lighter. When you are pushing 50-80 LBS of waste over 100 yards several times a day that lighter weight would help.

People who have horses also spend a lot of money on them, as do boarding farms, trainers and veterinarians. This is a product that would sell in high income areas.

Shouting out “so is plastic” just makes you arrogant. A better response would have been to discuss the application and where carbon fiber would be most efficient. Even if the student didn’t really understand why they had utilized that material, you could have shown leadership and a willingness to help other students. Those are traits that will get you much farther than ridiculing someone.

I agree that Carbonfiber is overused, but that seems to be part of a materials regular cycle in consumer products.

@PreDesign: Gotcha, thanks.

Gratuitous use of CF here, to great effect. How about that paint color.:exclamation:

"The Aventador J has a new monocoque and seats made of forged composites, a technique devoloped with the lab’s founder, Paolo Feraboli, a UW professor who also worked with Boeing on the carbon technology in the 787.

Carbon pieces are all over the Aventador J, which also uses a new carbon fiber fabric called “Carbonskin” that’s made of woven carbon fibers soaked with epoxy resin. It coats the cockpit and is used in seat inserts. Lamborghini’s release said other products may use this newly patented material, incuding high-end clothing.

Other carbon pieces include the large rear diffuser, a new X-shaped engine cover and fins on the bumpers “that act as flow deviators.”"

I respectfully disagree with you on this. Traditional alignments of fiber, cloth, tape or mandrel laid, are very strong in the directions of the fiber and weak directions across the fibers. Described as isotropic as you know. It is hard to provide strength across the layer leading to the risk of delamination, interlaminar shear. The compressed random arrangement can be very intertwined and can be used for very structural parts. I have seen some work that is in research and development that is only about strength and zero about aesthetics that uses this method.

Lamborghini calls the process “forged composite” because it is compression molded in a net shape. The analogy and the tooling of compression fits although there is zero flow with carbon as to be expected. I think it is pretty cool. The aesthetic is more interesting than twill as well, especially when the surface can be machined to reveal the random fiber effects.

MFP is the manufacturing weapon for Duqueine’s latest target: replacing complex metallic structures with composites that approach the high physical properties and precision of forged metal, but with the low unit cost of compression molding.
Applications in MFP’s crosshairs are aerospace parts, including aircraft seat fixations, or attachment rails — which are currently machined aluminum — and other aluminum or titanium seat parts such as handles, elbow rests and brackets. Their complex geometry makes them difficult to make in prepreg, but they are high in volume. The investment in the matched metal mold is justified by the greater volume. The material used is typically steel (e.g., 40CMD8, a hardened French alloy tool steel) to ensure sufficient resistance to the high compression pressures.

According to Aubry, “MFP also reduces the weight of the parts because we produce the same mechanical properties, keeping the same shape as the original aluminum.” The MFP part retains the same volume, but at a lower density — the density of aluminum is 2.6 to 2.7g/cm3 (0.09 to 0.1 lb/in3), and the density of CFRP using MFP is 1.6g/cm3 (0.06 lb/in3). Mass reduction is one of the principle drivers behind the use of the MFP process. Reportedly, MFP also is well suited for parts like clips, and it can make shapes with evolutions of sections (e.g., a box beam that “evolves” into a curved or tapered section), which are not easily reproduced in autoclaved prepreg.

Shaw, I see your point. And the example is very good too. However it is very different than what watchmakers does. It is probably carefully and statistically random oriented “beams” consolidated into a laminar structure, than pressed to shape. This careful preperation process shall ensure good properties. And during this, they probably soak the beams with thermoplastics, so that they can form it later with heat etc. I will look further into this process. It is still a process to save money, despite they say that it is as strong as usual methods, they do not give any specific strength values etc. And looking at their website they are still doing classical textile based. Anyway, I think what AP does is nowhere near this one.

And the “forged” name is just hype. How actual forging works has nothing to do with this. As there is no possible plastic deformation in the actual carbon strands, there is no meaning in calling it forging. Still they are free it call anything, but if I were them, I would not call it so.

I am now strongly considering to show the watch industry how it should be done by actually doing it the right way :slight_smile: . I have found some nice connections with some important figures. Wish me luck.

This thread makes me think of an old story of one of the Big Name Designers…for the life of me I can’t remember who…

The story I remember hearing is that they were interviewed by someone about Chrome and they went off on it. Saying how it is like the most useless, ugly finish around. This comment bit them in the a$$ when some big opportunity to design a product out of chrome crossed their table…I think it was faucets, or automobiles…or…

Sigh…the comment worked way better in my head.

I don’t think this tread resembles Chrome stuff. Chrome is almost never functional, and when it is functional it is sometimes in a place thats not visible (hard chrome coating). Contrarily CFRP when used right, is fucntional and very efficient. So if I get a chance to show how it should be used properly, I think I shall use it.
However your story is right to a big extent. Actually we are not artist and we cannot do whatever we feel is right. If the public wants it and if the company that you work for wants it, you usually have to do things that you do not believe in. So if a customer comes and tells that he wants a non-functional CFRP product, depending on many factort, biggest factor being usually money, one simply accepts the offer. Not that such stuff occurs too often.

You’re mixing messages. Because I can do the same thing and make a defense for chrome that is the same as CFRP:

“Contrarily CHROME when used right, is functional and very efficient.”

They’re material/finishes that play both an aesthetic and functional role. They’re very much part of the same discussion. You may not LIKE chrome. But that doesn’t make it any less appropriate or functional “when used right”.

There was an IDSA conference maybe 20 years ago. The opening speaker talked about how awful and polluting black dye in clothing was (is?). The next day, everyone was in blue jeans. The third day, 2/3 were back in black pants or jeans.

“Contrarily CHROME when used right, is functional and very efficient.”

Yeah, I guess that phrase can be used for almost any material, if one wishes to do. I still don’t think they are comparable in the context of this tread. Using one of the best materials ever for just looks is something that I do not believe in. After some research and calculations one can see that CFRP is the best material available for so many possible usages. Most of them stiffness related. For more details Ashby’s Material Selection book is a great resource. I think all designers and engineers alike shall have a look at this book.

Interestingly in many situations, beryllium alloys are on par with CFRP, but they are poisonous. Wood is usually a great candidate, it is not preferred due to its variable nature in high performance applications. But again, many times wood is selected for many applications.

Using one of the best materials ever for just looks is something that I do not believe in.



But again, many times wood is selected for many applications.

And what were burnt umber (oxides of manganese) , ocher (oxides of iron), and sienna (oxides of iron) first used for?

Paint. Which was used to conceal or change the appearance of another material. Interior trim panels of carbon fiber, or aromatic sandal wood … it doesn’t make any difference (discounting endangered species), in the context of much of this discussion, the “use” of material is as much on the aesthetic, as much as the structural.

Is CFRP overrated? Structurally no. It may even be underrated.

Why do we use it (assuming for the moment the OP meant, 'use it excessively)? Starting in prehistory, man has embellished everything he has made with anything he could lay hands on. Why should the use of CFRP any different?

You realize, right, that this is a purely subjective statement?

Not that the original question of whether it is overrated, isn’t subjective, either. But how do you define “best materials ever”? As designers we have to be able to tune a discussion that is founded in subjectivity to a context that allows everyone to have some kind of rational discussion that doesn’t get mired in “I like blue, blue’s the best color ever”.

The primary reason for my comparison of chrome to CFRP is that they are both materials that serve specific purposes. They both get (over)used in situations that are, subjectively, inappropriate. Chrome has served the pick-up truck market very well.

The other reason for the comparison of chrome to CFRP, is that there was a very well known Designer who publicly trashed Chrome in an interview, or something, and then was trying to woo a client who uses a LOT of chrome and effectively got told off because of it. I still have zero recollection of who the designer was, and who the client was…heck, I am so tired from staying up with a barfing 5 year old, I don’t know if the story is even true. But in my head it is a fantastic anecdotal commentary on this thread :slight_smile: