
Wood pulp extract stronger than carbon fiber or Kevlar (2012) - jtraffic
http://newatlas.com/cellulose-nanocrystals-stronger-carbon-fiber-kevlar/23959/
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slackingoff2017
Im not too surprised. The strength of plywood is well known in aero and racing
circles. For parts like stringers plywood is used instead of fiberglass when
higher stiffness is required.

Plywood is similar strength/weight as fiberglass which isn't too far off from
carbon fiber.

The issue with all popular composite materials like fiberglass, carbon fiber,
and plywood is that their strength is highly directional. It takes a lot of
skill and testing to make sure your part is strong enough in all directions
force will be applied.

There's some omnidirectional "mat" type materials you can get easily for
fiberglass but you exchange the directional strength of weave for a non-
directional but overall inferior strength of randomly oriented strands.

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pacaro
Strip planking is popular amongst canoe builders. A 1/4inch thick core of
cedar has fiberglass on either side. The glass provides tensile strength and
the wood provides both compression strength and a useful offset between the
fiber layers.

I can lift the bare hull of an 18 foot long sailing canoe with one hand.

The downside is in maintenance/repairs, and the critical requirement to keep
through holes absolutely watertight. If water gets into the core it's a total
PITA

Also, strips of cedar that are 3/4" by 1/4" by 18' are really weird to handle.

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KGIII
The Mosquito, a plane from WWII, was largely made of wood and is considered
one of the best planes from that era.

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andyidsinga
YES!

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omarforgotpwd
Stronger at 10% of the price of carbon fiber. So why haven't we seen more
people using this material in the last five years?

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Maarten88
I was watching America's Cup sailing last week and these boats were all carbon
fiber, completely. If there was a material stronger and lighter, even by a few
percent, at any price, they'd be using that. They would do just anything to
gain an advantage.

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rogmet
I didn't read the rules for the most recent Cup but previous editions have
limited the allowable materials and processing techniques in the rules,
setting a limit on fibre modulus to prevent the better funded teams from going
all out on eye-wateringly expensive M55J carbon for example. Cure pressures
were limited to 1 bar vacuum (atmospheric) to keep the rich guys out of big
and expensive autoclaves for their hulls and primary structure. There was a
maximum density requirement for the keel bulb material forcing you to use lead
rather than platinum, gold or depleted uranium! These (nano? micro? mini?)
fibres would likely be used as an additive to the resin, then laminated with
everyday carbon - usually the first failure method to occur is resin
microcracking which these little guys could helpfully and cheaply delay.

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mixedbit
Also take a look how strong and abuse-resistant cross laminated timber is:
[https://alexschreyer.net/engineering/much-abuse-can-cross-
la...](https://alexschreyer.net/engineering/much-abuse-can-cross-laminated-
timber-clt-take/)

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eutectic
Carbon fiber works so well in composites because it is possible to create
long, continuous fibers which can be woven into cloth for directional
reinforcement.

Maybe it is possible to use the strengths of each by adding CNCs to carbon
composites.

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chroem-
Nitpick: fabric lay-ups are rarely used in industry because the weave exerts
shear stresses on the fibers, making them weaker under load. Aerospace
composites are all unidirectional.

But fiber blends are very common. It's typical to mix CF, glass, and aramids
to get the price and properties you want, though I don't think it would make
much sense to mix chopped and continuous fibers.

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eutectic
Thanks for the correction, my bad. The technical term for the kind of thing I
was thinking of is 'multiscale composites', and there already seems to be a
lot written about carbon fiber/carbon nanotube mixed composites which would
presumably be similar to carbon fiber/nano-cellulose composites. I obviously
can't claim to be an expert, but there at least seems to be some precedent.

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dsfyu404ed
Hmmmm. I wonder how its material properties change in the -40 to +300F range
and if the chemicals involved can tolerate immersion in oils.

With the weigh/strength characteristics and requirement that it not see water
I can see this material being used in indoor (or sealed inside a gearbox
somewhere) applications to reduce rotating mass.

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JonRB
I'm delighted by how in-depth and detailed this is!

I'd be interested in seeing the numbers for how much the final product
_weighs_ in comparison to Kevlar/Carbon Fibre...

I'd also love to know if this research went anywhere since 2012

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Scaevolus
> CNCs... bulk density is low at 1.6 g/cc, but they exhibit incredible
> strength. An elastic modulus of nearly 150 GPa, and a tensile strength of
> nearly 10 GPa.

This is the same as carbon fiber (1.57-1.7g/cc), and slightly higher than
kevlar (1.44g/cc).

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imaginenore
I think it since got surpassed by UHMWPE, which has a tensile strength of
~20GPa. They make cheap body armor out of it.

[https://en.wikipedia.org/wiki/Ultra-high-molecular-
weight_po...](https://en.wikipedia.org/wiki/Ultra-high-molecular-
weight_polyethylene)

~~~
owenversteeg
UHMWPE is a beautiful thing. As easy to cut as wood, you can bend and mold it
at temperatures over 300F, and it's strong enough that a 0.9" thick plate can
stop bullets. Specifically, by "bullets", I mean a NIJ-0101.06 level III
threat. That could be up to 24 shots from an AK-47, FN FAL, or AR-15.

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AdmiralAsshat
No wonder it's so popular as a binding agent for fake cheese.

