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Well, not to contradict jagboy, but they're called (AFAIK) fuel bladders. Fuel cells are another gadget, to be precise.

Bladders themselves cannot be made of Kevlar: not only they would be affected by fuel, Kevlar is also affected by water (and some it's in fuel) and, again, to my knowledge, there is no impervious Kevlar. The fuel bladder is reinforced with Kevlar but the container itself it's made of another material.

Kevlar is used in HANS, or so says its inventor (at least when it was introduced). Now I have the time to google for what I read: http://www.iht.com/articles/2003/04/05/prix_ed3_.php

Of course, if you make them, you can tell us what you made them from...

What about the tires?

With all this info I now wish I wasnt soley doing it for application in aerospace

But yeah, a big thanks to people for infomation provided.

Ciro Pabón wrote:Well, not to contradict jagboy, but they're called (AFAIK) fuel bladders. Fuel cells are another gadget, to be precise.

Bladders themselves cannot be made of Kevlar: not only they would be affected by fuel, Kevlar is also affected by water (and some it's in fuel) and, again, to my knowledge, there is no impervious Kevlar. The fuel bladder is reinforced with Kevlar but the container itself it's made of another material.

Kevlar is used in HANS, or so says its inventor (at least when it was introduced). Now I have the time to google for what I read: http://www.iht.com/articles/2003/04/05/prix_ed3_.php

Of course, if you make them, you can tell us what you made them from...
What about the tires?

I dont make them anymore, I made some prototypes.

They consisted of normal woven carbon, unidirectional fibres and expanding structural foam.

They were tricky to laminate given their shape and also that they were in an enclosed mould, so you could not rely on the vacuum bag for consolidation.

We made a few scrappers before we cracked it!

As for tyres, I really dont have a clue!

Thanks for the explanations, FW21.

One last question: what did the straps for the HANS were made of? I had the idea that this is the place where Kevlar could be used.

Then, I checked tensile strengths (I had no idea of their values, I confess) and I found that carbon fiber can take the incredible amount of 5650 MPa (that's like three times the resistance of high-tension steel) but is brittle (also, I had no idea): it does not yield, like steel, it snaps suddenly, like concrete (I'm a civil engineer, sorry).

So, I don't know if I'm wrong when I think CF is not used, woven, into ropes or straps. Kevlar has a yield strength around 3700 MPa: it's less resistant than CF, but it yields.

I also found "in the Internets", to my amusement, that spider webs are NOT more resistant than Kevlar or CF, they have less strength, but they require more energy to be broken (another bit of information I did not understood very well, as the only reference I got gave spider web a puny 1200 MPa...).

Finally, if I were in PNSD position, I would somehow introduce in the presentation the story of a company from Texas that put spider genes into some goats (I am NOT making this up, I swear), sort of "Peter Parkerish" thing, so the goats were able to produce spider web protein in their milk. Apparently, the problem is in how to spin it; the company failed in their attempts: they were not able to go from purified protein to woven threads. All in the name of a better thread.

Ciro Pabón wrote:Thanks for the explanations, FW21.

One last question: what did the straps for the HANS were made of? I had the idea that this is the place where Kevlar could be used.

Then, I checked tensile strengths (I had no idea of their values, I confess) and I found that carbon fiber can take the incredible amount of 5650 MPa (that's like three times the resistance of high-tension steel) but is brittle (also, I had no idea): it does not yield, like steel, it snaps suddenly, like concrete (I'm a civil engineer, sorry).

So, I don't know if I'm wrong when I think CF is not used, woven, into ropes or straps. Kevlar has a yield strength around 3700 MPa: it's less resistant than CF, but it yields.


I also found "in the Internets", to my amusement, that spider webs are NOT more resistant than Kevlar or CF, they have less strength, but they require more energy to be broken (another bit of information I did not understood very well, as the only reference I got gave spider web a puny 1200 MPa...).

Finally, if I were in PNSD position, I would somehow introduce in the presentation the story of a company from Texas that put spider genes into some goats (I am NOT making this up, I swear), sort of "Peter Parkerish" thing, so the goats were able to produce spider web protein in their milk. Apparently, the problem is in how to spin it; the company failed in their attempts: they were not able to go from purified protein to woven threads. All in the name of a better thread.

As far as I remember, the straps were not woven carbon.

I will try to find out what they are made of, the ones I have seen lately could be kevlar as they have a similar colour.

But I dont think they are

Having never made a tub - or anything in Carbon Fibre - I have to bow to superior knowledge from those actually do it.

But it is used in some chassis - though not F1 it seems!

Kevlar is used in composite hockey sticks too, to reinforce Carbon Fibre. It works as something like a shock absorber cutting down on vibration.

The page by Dupont on Kevlar mentions it's used in:

- chin straps on HANS devices (maybe only in NASCAR?)
- engine belts
- tyres
- wheel retaining straps
- clutches
- gaskets
- hoses
- and (very useful for taking the bullets from critics in F1 ) body armour.

http://www2.dupont.com/Kevlar/en_US/use ... otive.html

FW 21 wrote:Normal carbon doesnt allow signals to pass through (or hampers them considerably), but they can pass through kevlar.

If thats the case, then why are the steering wheel and column constructed from carbon-fibre? When they are packed with plenty of crucial electronics.

F1Technical wrote:The main part of the wheel however is constructed, just like almost every car part, of carbon fibre to reduce its weight.

Steering Wheel

After reading this I've been looking for any documents that confirm the influence of carbonfibre on electric signals, but I wasn't able to find any thing.

Can anybody enlighten us on this subject.

There are articles about how carbon fiber presents a resistive load to electromagnetic waves alllll over the internet. I will say that I failed to find a particular research paper documenting it with a quick search, though.

Title : Carbon Fiber Electrical Resistance Modification - Its Relationship to Electrical Equipment Malfunction. Executive Summary.

Descriptive Note : Final rept.

Corporate Author : AEROSPACE CORP EL SEGUNDO CALIF

Personal Author(s) : Barry,W. T. ; Diefendorf,R. J. ; Dresselhaus,M. S. ; Gray,R. I. ; Hawthorne,M. F.


Abstract : A problem exists in the operation of electrical equipment if carbon fibers come in contact with critical electrical circuits when accidentally dispersed into the air by a variety of means. The extent and severity of the problem has not been fully evaluated and, indeed, may be overstated. Therefore, there is an urgent need for a comprehensive theoretical and experimental risk analysis that includes all major uses, i.e., aerospace, transportation, and consumer products and manufacturing practices. A Carbon Fiber Study Group was convened to consider whether or not the electrical resistance of carbon fibers could be increased to acceptable levels without altering other desirable characteristics. The group considered (1) the magnitude of resistance changes required to minimize electrical equipment malfunction, (2) whether or not carbon fibers can be modified to meet these requirements, (3) the ease of hardening confined spaces, and (4) the disposal of carbon fibers and composites after use. Conclusions, recommendations, and background information are presented herein. (Author)

Descriptors : *CARBON FIBERS, *ELECTRICAL RESISTANCE, *CIRCUITS, *ELECTRICAL EQUIPMENT, MODIFICATION, PROCESSING, INSULATION, ACRYLONITRILE POLYMERS, NITROGEN, COATINGS, CONTAMINATION, MALFUNCTIONS.

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