The future of carbon fiber? Affordable for most vehicles ?
 

Bellow I explain about the 2 new ways to make carbon fiber affordable in near future.
(I need just 1 more post to be allowed to post links and images).

We kow carbon fibar it's very expansive. Expansice to produce the fabric sheets, and expansive (slow time consuming) way to work with.

Bu I remambered about two interesting news about carbon fiber, about possible dramatically reduce cost of manufacture and cost of working labor, one from my country Brazil, and other from EUA ands other researchs.

The brazilian research developed a carbon fiber made from petroleum tar, with very reduced cost, about 15 dollar per kg.

https://exame.abril.com.br/tecnologi...ra-de-carbono/
http://www.tecnologiademateriais.com...bro/piche.html
(I didn't found a english news about it, so use translator)


The other research is finding ways to better and faster place and shape layers of carbon fiber, by using powerfull infrared lasers. Article from 2016, but since 2010 or so they talk about use of lasers.

https://www.nextbigfuture.com/2016/0...matically.html
https://newatlas.com/fraunhofer-lase...process/14635/

If both researches get succcess, we can predict a near future with a lot of carbon fiber being used in many more aplications. Let's cross fingers.

I know carbon fiber aone it's not ideal, since it's not very eleastic and bracks suddenly insteadof bend first. But it can be used combined with other materials for reach specific goals.

BMW and other 3rd parties have been stating for 10 years that fiber can be produced at the same cost as steel.

A few 3rd parties claim to have the tech to make fiber at 1/10 the cost of steel but have no takers due to 10+ year design cycles

Meanwhile we need all cars and trucks to be under 2000lbs to meet efficiency standards, there are some who believe this is fully possible but auto companies are slow to adopt and loath being stuck with the same dies and design for 10+ years.
It has also been found big lightweight vehicles are just as safe as big heavy vehicles due to the crumple zone being the same.

Beyond government I see no way to make these parties come together, I also doubt GM and Ford would be willing to share dies to get the cost out either.

Ah well, fiber is always 10 years away, see if that ever changes.

I hope alternative vehicles industry arrive, instead of we wait to the big ones change.

The brazilian carbon fiber from petroleum tar already had a semi industrial instalation. If the cost for carbon fiber sheets get better, people would at least have lower price for DIY projects.

Cars can be safer with reinforced driver area, but the crumple zone it's important to absorb impact.

One thing anoys me. The carbon fiber shappingg made in home, like we see in youtube videos, do not use autoclaves, and many carbon fiber sheets looks very crap, not even solid. I presume that withouty a autoclave it's impossible to create really resistant carbon fiber like in formula one cars.

Problem is carbon fiber has amazing compressive strength, then it fails catastrophicly. Where steel and aluminum by nature bend when they fail, not shatter.
I worked with carbon fiber many years ago and I'm not saying it can't be done, I just don't know how it would be done.

Gonna be a PITA to recycle a mostly carbon-fiber vehicle, at a guess. But it would be nice if it became commonplace for sports cars and eco cars...

Things like carbon fiber and fiberglass have pretty limited recyclablity.

If it doesn't rust it can be repaired "forever".

When it cant be repaired any more, it's energy can be recovered by burning it.

Burning carbon fiber and epoxy was a small part of a class action lawsuit in the 90s against the DoD for civilian contractors who worked in locations where the waste from classified projects was burned to get rid of it and later on developed a large number of rather unusual health related problems.
Burning carbon fiber may not be a good idea.

Carbon fiber can't be recycled to the same quality. You would get a second class carbon fiber, not god enough for standarts asked for cars. It could be used in other applications perhaps.

If you have a large piece of carbon fiber, like a car's hood, and it broked in a small place, you need to change the entire piece. At least at present day.
Perhaps in near future the high end layers could have a portable hand version tool to"solder" a nem piece of carbon fibar to fill just the hole and keep most of the original strength.


If the carbon fiber it's so flexible, like a pepar, looking just the fabric in rolls, is it just the epoxi resin that give it hardness, or the autoclave process indeed have a hardening direct in the carbon fiber sheet ?

I found that carbon fiber need to get pyrolisis, but I don't knoiw if it's just in the manufacture of the sheet rolls, or if it's also for the shape process.

I saw a video once, about little fine sticks of carbon fiber resisting hard strikes with a metal bar. But in other videos, like from carbon fiber pieces from bikes and videos of carbon fiber pieces made without autoclave, the pieces broked easily with hammer, and didn't look very hard or rigid.
A bike made of carbon fiber broked easier than steel and aluminiun :

https://www.youtube.com/watch?v=bOraxyz8HZ0
https://www.youtube.com/watch?v=Sp40gAkdV3w

And this other was weak for weight presure :


https://www.youtube.com/watch?v=nvk63bmVpck

I know it depends of how many layers and final thickness and the direction of fibers, the way to combine sheetas in different direction. But something that is suposed to be many times stronger than steel... It would be more resistant, do you agree ?

When they compare carbon fiber's resistance to a given number times the resistance of steel, is the comparison what is the reference ? The same thickness for both, or same weight for both ?
One video used weight as reference, but I don't know if it's the official reference or not.

Carbon fiber can be great, otherwise it would not save Formula-1 drives so often, I know. So I'm not challenging science or creating conspiracy theories. But watching these videos above we get a bad feeling, like it appears poor for impacts, poor for pressure and weight, poor for resistance for cutting or drill... What what is left for quality ???

Maybe there are good and also very crap carbon fiber products.

Why carbon fiber it's always made with epoxi resin together ? Why not other resin or composite?
Aptera car shell had good resistance to a hammer impact test, made in a silica-based fabric composite. It deformed a little and returned to original shape, dissipating energy.

They could create a new carbon fiber, with other composite together, to behave with some of the energy dissipating approach.

it isn't always epoxy, there are other resins and binders in use. Epoxy is generally used in the home-manufactured parts because epoxy is not as stringent to control , less toxic, available, cheaper.

I just don't see anybody with a 4 ft x 4 ft x 4ft oven in their backyard to do exotics or ceramic.

remember when GM shaves a buck from each car they make, it is a multi million dollar annual profit.

I could of sworn BMW said all their cars would be CF in the near future.

Looking that up I found this article instead.

BMW is selling its stake in SGL carbon fiber joint venture
November 24, 2017
http://www.autonews.com/article/2017...bonfiber-stake
Steel is not going away without a good fight, and aluminum is here to stay.

There is a future for CF, just not going to be a slam dunk we once thought it was going to be.

I think I'd rather see cars made from more wood than carbon fiber. As stated by others, the sharply reduced usefulness of recycled CF is part of the reason. There's less entrained energy in a part made from wood, and you can engineer wooden members with known, predictable strengths and yields.

It wouldn't shatter as abruptly as CF when it fails, either. I think it's completely within the scope of existing technology to engineer wooden structural chassis members that can contribute to predictable crash force dissipation.

Did you watched these videos (since it was in the very end of page 1 thread) ?


https://www.youtube.com/watch?v=bOraxyz8HZ0
https://www.youtube.com/watch?v=Sp40gAkdV3w

https://www.youtube.com/watch?v=nvk63bmVpck

I believe a autoclave made a big difference. But I would like to understand why, what it do to the carbon filaments, or if do some extra thing just to the epoxi resin. It wasn't important they would not use.
It carbon fiber without a autoclave it's weak, not really rigid, why take the expanse of carbon fiber fabric sheet ?

There is a intermediary process, a oven and so without high pressure of a autoclave, but just high temperature, like the one used for produce this carbon fiber chello :


So I conclude there are 3 qualitt degree for carbon fiber shaping, not considering the quality of the fabric sheet.

1-Non autoclaved (trash or almost) and nohigh temperature : Produces trash carbon fiber.
2-Hight temperature (not sure if high as in a autoclave : Intermediary rersults.
3- Autoclave treatment, with high temperature and high pressure combined : Produce true carbon fiber ressistance.

Steel reinforced concrete I can understand, since the rigid steel and the flexibility of steel under high forces make the concrete stronger, as a skeleton makes our body stronger. But carbon fiber... if the carbon filaments of the carbon sheet do not get rigid, the only thing to make the final piece rigid is the epoxi resin. So the rigidity would come just from the resin and nothing more.

I know there is more things, like forces of tension and traction. But we must or art least should expect rigidity for carbon fiber.
People said carbon fiber can be up to 0 times stronger than steel, but all tests I saw was only up to 3 times stronger. I wonder if 10x stronger are reality or just talk.

Is the comparisons based in carbon fiber of same weight of a piece of steel, or based in the same tickness of a piece of a steel piece?

I'm laughing hard with this video, since the carbon sheet looks like a papersheet after epoxy cure :

https://youtu.be/243L3yeoe0c?t=764

Is he making carbon fiber or preparing to cover a book with protective plastic ?
The guy said it's because it'sw just one sheet bu a single sheet steel would never be such flexible. And if the made a 3 layers sheet, it would be flexible if was 3 times larger.

I challenge anyone to prove to me that these home made carbon fiber are stronger than steel. If even the carbon fiber bikes was a joke... worse for impact, for pression of weight and for drill and cut.

One more evidence that home made carbon fiber it's a garbage, if compared to the proposed 4x stronger than steel clains we always heard on TV.

https://www.youtube.com/watch?v=oDo5z96Y6_g

The usual lame crap excuse many carbon fiber home made people said is : It have just few layers".

But in this video, in you response to the comments, the guy said it had 3mm or 4mm.
Honestly if was a 3mm or 4mm steel plate it would not broke by a person with strong hands.
And if carbon fiber is at least 3 times stronger than steel, it's like he was broking a 9 mm or 12mm tick steel plate at least.

I still challenge someone to prove me that a home made carbon fiber is stronger than steel. Right now for me, based in these videos, it's just crap.

Strength claims are based on weight, not thickness or volume. As you know, the strength of both steel and CF depend on what kind it is.

I think there is huge potential in the automotive industry to implement CF, but costs must come down and the automation process must improve.

Weight is relatively unimportant for automobiles compared to other vehicles. As I've read elsewhere, the larger the percentage of a vehicle is comprised of fuel, the more important it is to reduce weight. Rockets are about 90% fuel by weight, so exotic lightweight materials are cost effective. Airplanes are about 40% fuel, so they have a medium need for lightweight materials. Cars are only 10% fuel, so they don't benefit as much by expensive forms of weight reduction.

Uhhnnn... But they always told us : "Carbon fiber... a lot stronger than steel and a lot lightweight than steel, so now we can build cars much more stronger and much more lighter."

So it's not so stronger and lighter at same time. And based in your information I conclude the pices of CF need to be much more ticker to compare or surpass steel.
It would take countless layers (and $$$$$) to get really 3 times stronger than steel. Unviable for DIY projects of eco vehicles (unless we accept a not resistant final work).

Sorry to disagree with you now. But a rocket it's mostly fuel in weight, so if you cut for the weight of the empty body of a rocket in 99%, it would still be incredible heavy (98,99% of weigh if with fuel added), due the weight of fuel.
A Airplane would take some benefit.
But a car, with only 10% of fuel weight of total weight, and so a90% of weight for the car's body (shape/reels/motor...) and if we could cut 70% of the body weight, the final car (with fuel) would be 40% of the initial car's weight with fuel.
You had reversed the fuel weight important analysis.

Ok but I need several parameters defined: weight / mass of finished product, resistance to how much force applied where and how, binder materials and their specs, resins specs for filling the matrix, cure process, Attach points, etc. If it is a simple pull test then the comparison can be done easy peesey. How strong is 10 mill steel 1" wide? (I already know this.


Btw when you say home made, what do you really mean?

I find this the earliest, clearest statement of your question.

To my understanding (YMMV), the hurdle for mass production isn't cost so much as speed (and possibly yield rate). And the lack of high-speed production is down to the vacuum-bagged autoclaving. It's purpose is to minimize the amount of binder — epoxy or whatever — in ratio to the fibers, to maximize strength (toughness, whatever) for weight.

On to the larger question, the future of carbon fiber. That would be in 3D printing:
https://upload.wikimedia.org/wikiped...ti_overall.jpg
https://en.wikipedia.org/wiki/Strati_%28automobile%29

OTOH it's future will include competition:

https://en.wikipedia.org/wiki/Basalt_fiber
Read it and weep.

Same is true for fiberglass and resin--too much resin actually weakens the final product at the same time as it's heavier than it needs to be. All those "crap" homemade carbon pieces probably suffered from this.

To my knowledge, the autoclave process does not harden the fibers themselves. I've examined smashed bicycle frames, for instance, where the fibers tore, and they're still quite flexible.

With carbon fiber, you have to look at where the force is applied and in what direction. Depending how you orient and lay the sheets, the finished product will be stronger in one direction than another. Those bicycle forks, for instance, were not designed to resist a concentrated force on the side of one leg; they were designed to resist vertical forces from the mass of the rider transferred to the wheel and then road. (Same theory as a spoked bicycle wheel--they can be quite strong vertically, but you can easily pull a tensioned spoke from the side and rip it out of the hub or rim). Gram for gram, carbon fiber bikes are much stronger than steel or aluminum, and thus can be made lighter (and made into complex shapes more easily). They're also more comfortable than aluminum, as carbon fiber absorbs more road vibration.

I forgot one. The big competitor might turn out to be densified wood.https://www.scientificamerican.com/a...-s-super-wood/

They then go on to discuss a transparent wood-Lucite composite!

It's too much information... Jesus...
It would lead to dozen possible combinations. I want to know about the average carebon fiber made in small garages/home, following rightfully the manufacturer specifications, without autoclave or ovens.

The worse carbon fiber fabric sheet, if well used, is at least 3 or 4 times stronger than steel.

About the weigh be the right reference to comparison with steel, in this video about failure of carbon fiber, the weight it's not so different, near aluminiun weight and more more than 50% the weight of steel.
CF: 1.15
Aluminium: 1.45
Steel: 2.16

If you work or had worked with carbon fiber, I apologyse if my comments sounded rude ar unkind. Maybe it's just some ignorance of mine about some technical aspect somewhere.

Maybe the best would be the composite used in Aptera car, made of silica, strong to resist hammer impact, aborbing energy by some few deforming (reversible if not much). But we don't know the price for such materail and labor.

https://youtu.be/nvk63bmVpck?t=41

I looked that and found this:

https://www.reviewjournal.com/uncate...-entirely-new/
Also read a story about disenchanted workers taking forklifts and crushing some body shells in spite, posted on Youtube it said.

https://www.youtube.com/watch?v=yGqhKLFS62k

https://www.youtube.com/watch?v=dGGhH1LlUUE

Every time I see those videos I get angry.

Such a beautiful car, destroyed by a bunch of pump-and-dumpers.

English as a 2n language aside, I went back though the thread and find everyone helpful and un-antagonistic.

On to the subject of homemade carbon fiber. I haven't worked with it, I don't like stuff that gives off fumes. But my understanding is that carbon fiber is limp but it resists draping. IOW you wind up poking it into recesses and it pops back out. Sorta passive-agressive.

Vacuum bagging is a low-cost way to avoid needing a two-part form, the air pressure is conformal.

Simply put, your mileage may vary. Are you making a gear shift knob or a whole car? Do you have a clean dry work space with a finished floor? Working out at the curb or under a tree (like Eastern Oregon)?
We have a member that is in the jungle of Costa Rica, we probably have members is upscale communities in New Zealand.

Why do you disallow vacuum bagging? You can probably do it with a second-hand water bed and a vacuum cleaner.

Since you are still poised to dive in, I'd have you consider basalt. https://www.basalt.guru/

http://www.pulwellfrp.com/editor/att...55935_4556.jpg
http://www.pulwellfrp.com/editor/attached/image/20151204/20151204155935_4556.jpg

Basalt doesn't shatter like carbon fiber, it dents instead. To make an arbitrary shape you could start with an open mesh, cut and stitched, and then lay fabric on to surface it.

The challenge is completely wetting the fibers without excessive resin.

Sorry, only now I saw this post of yours.

Interesting, and it's true, but I read about they use CF sheets in layers with different fiber orientations, to get strong in many directions.

And the simple fact of use a region with local angle different, turn it less prone to bend (flexible in a given direction). For othjer side less flexible also means more prone tp broke :

https://www.youtube.com/watch?v=0MuXV3ywH_U

But watching videos like this, https://www.youtube.com/watch?v=Dj2kUqb8Tac
I can't imagine/feel it as stronger than still. 270 nestons are not much, since a little hydraulic shock absorber used in closets or kitchen cabinets have 150 newtons.
Carbon fiber it's a cable, a strong cable on a jail of epoxi resin. If epoxi resin are not strong enough to keep the fiber on jail under pressure... we have a problem.


Again, one more crap carbon fiber product :

https://www.youtube.com/watch?v=gOjs84ShSp0

Who knows a carbon fiber product for sale that do not behave like a crap ?




Like the feeling of watch EV-1 holocaust ?

Maybe these aptera's shells wasn't finished, not all layers, or the little car that puledl it against the wal was really very strong.

Anyway his topic is going about to be collection of "Super Material" going fail. What is the kryptonite of all that stuff?

Most of the fuel in a rocket is consumed merely accelerating the weight of the fuel. To add a small amount of payload or rocket structure, more fuel must be added, but then a lot more fuel must be added to simply accelerate the weight of the additional fuel. For this reason, a small difference in weight translates to big differences in fuel consumption.

Aircraft have a higher payload to fuel ratio than rockets, but it is still not great. Adding a little weight has a medium impact on the additional amount of fuel required.

Automobiles have a very high payload to fuel ratio. Adding a small amount of weight has little impact on the fuel consumed. Add 200lbs to your car and drive 100 miles on the highway, and you won't even be able to tell the difference in fuel consumed. Any fuel consumed going up hill is recaptured coming back down the other side. In fact, moderate hills can be more efficient for driving a petrol car than flat roads (forced pulse and glide).

The higher the ratio of payload to fuel, the less important weight reduction is.

As shown in this forum, aerodynamic improvements are much more effective at improving fuel economy than weight reductions.

As you point out, carbon fiber is strong as long as it is engineered to take advantage of its strengths and avoid its weakness.

How much would a bow rod made of steel weigh? A similar diameter and thickness steel rod could be stronger, but it would also be much heavier.

Most bicycle enthusiasts prefer a carbon fiber front fork both for weight reduction and bump absorption. There are plenty of consumer products where CF is the appropriate material of choice.

Am I interpreting that correctly? 'Kryptonite' would be Polymetal:

http://ecomodder.com/forum/member-fr...1-100-0866.jpg

It's prefinished. A 3mm sheet is equal to 5/8" plywood. (The same stuff that clad the Grenfell Tower.)

Once you are on the road, the weight it's not very important and aerodynamics it's the main issue. I totally agree with you, in these terms.
But once you are in a ascent/clive, the overal weight it's very important. And every time you need to desaccelerate and accelerate again, like driving in the city, weight became important.

About carbon fiber, I'm judging in pracvtical ways. The products I saw on videos broke too easily. To me this is enough to say carbon fiber, in real world aplications for non miliomaires consumers, it's a crap.
Sure it's great for Formula-1 driver and for the army, but not much for us.

I bet many people are doing carbon fiber in home, paying a ot, to get a poor finished product. They are not NASA to calculate fiber direction interaction model to a given type of impact or forse, to be suitable to given number of specific aplications.

Kryptonite is the bad resin curing, the bad fiber orientations shape, bad project, poor layers... the high costs that lead manufactures to use a small amounts...

You have to look at how fuel is spent in each application. In automotive applications, most energy is spent overcoming aerodynamic drag. The amount spent accelerating mass is relatively small. I'm not saying weight reduction doesn't matter, only that it matters very little compared to other applications.

For rockets, most of the fuel is spent accelerating mass, therefore reducing mass is critical, and spending money on exotic lightweight materials is justified.

Shaving 50 lbs off of a vehicle doesn't much impact fuel economy.

I agree that home use and low grade consumer CF is not so good. This is why we don't see it commonly used. To do it right is expensive, and to do it wrong is pointless.

What about solar photovoltais area in the upper surface, compared to two kinds aerodynamic values ?

I was wondering if, for example, a 0,05 drag with low area for solar cells, could be worse than a 0,1 or 0,12 drag vehicle with a huge area for solar cells.

I will make a drawing about a solar "Morelli" or "solar Aptera" I imagined.

Bambu it's a super wood, in ecologic terms. It grows super fast, grown super together (close each other) and it's very strong, much better than plywood.

There is some bambu boards used tom cut meat, really strong, made by many pieces of bamboo glued together in high pressure.
There are projects fo try crerate a MDF made of bambuu fibers.

University of Maryland's engineering professors; Teng Li, a mechanical engineering professor and Liangbing Hu created a process to make wood stronger than titanium and metal alloys and it is six times lighter! The team modified the material and mechanical properties of natural wood to make it 10 times tougher and 11.5 times stronger. The process involves chemical and mechanical processing to alter the plant cell structures. Toughness refers to the durability of the material, whereas its strength depends on how much stress it can take. They see it a replacement in designing and manufacturing vehicles.

https://www.nature.com/articles/nature25476

https://www.engineering.com/Designer...-Titanium.aspx

You would need to use a computer model to calculate the projected power increase vs the projected aerodynamic penalty, or create a scale model and test. Many variables involved.

My sense is that solar is useless on a vehicle. Under ideal conditions (pointed directly at sun and no clouds), there is 1kW of sun energy available for every 1m^2. You might get 25% of that in electricity, so 250 watts. That's roughly 1/3 of a horsepower (746 watts) for every square meter of direct sunlight.

The added weight, cost, and aerodynamic penalty for using solar cannot be offset by the meager output.

https://youtu.be/-lI_0iIcmdU?t=370

Supose you already have the drag for both. Drag, weight, power of electric motors, all for both.

A solar panel do not need to have the same power output as the power of the electric motor. With batteries you can store some energy everytime you park on sun or reduce speed a lot. On road in cruiser mode you only use a fraction of the power of electric motor, if have good aerdynamics and the road have no climb.

Solarworld No1, Morelli based, similar to Aptera, have a 1800W solar array, using 29% efficient solar cells.

http://www.upontheroof.org/wp-conten...ar-600x354.jpg

Yes, it's very neat as an engineering feat, but not practical or applicable to consumer vehicles. 1800W is only 2.4 horsepower, which might drive that car at 55 MPH under ideal conditions. Even if the car were left in the sun to charge, 1.8 kWh is a very low rate.

Vehicles are among the worst place for solar panels. Much better to put them on a roof and angle them to be efficient.

All this talk about carbon fiber reminded of this car, photographed yesterday at the Chicago Auto Show:

http://ecomodder.com/forum/member-vm...219-150127.jpg