Wood pulp extract stronger than carbon fiber or Kevlar (2012) | Hacker News Reader

Wood pulp extract stronger than carbon fiber or Kevlar (2012)

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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.

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.

Snowboards are kinda similar with usually having a wooden core for tensile strength with plastic bottom for gliding, plastic top for protecting the wood and metal edges to cut into snow/ice.

Get a hole all the way to the wood (usually by hitting some rocks on the rather soft/porous plastic bottom) without keeping it dry and patching quickly will destroy the board very fast.

Also modern boards have multiple different kinds of wood in fancy layers/placements inside to give the correct amount of "pop" in the correct spots for the wanted ride. Some of the more expensive/extreme boards have started to replace parts of the wood core with carbon fiber in the cases where weight is very important and a very stiff board is preferred (mainly backcountry/split boards)

GM used balsa wrapped in carbon fiber for a previous version of the Z06 'Vette for similar reasons [0]. It's light, it's strong, and it's cheap.

[0] http://www.autonews.com/article/20050912/SUB/509120708/balsa...

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

YES!

End-grain balsa wood is a surprisingly common core material in high-performance composite structures.

Also bigger (sail)boats have been home-built using strip blanking technique. The downside is weight penalty over balsa/foam core.

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?

Yes, I often wonder too where all these new inventions are gone after the initial enthusiasm and media attention fades. Probably every weeks you can find articles about 'breakthrough' in material science, battery, memory technologies etc. Yet when I try to Google them after few years, >90% has no follow ups nor these technologies reach market. I guess this is like startups -- good idea is not enough, execution and financing is what matters.

To an extent, also a lot of these processes are incremental rather than revolutionary (despite the press releases) and do eventually make it through to production after an upgrade cycle or two.

Hell a carbon fiber (partially) plane flew around the world non-stop in 1986 but it wasn't until 2012 that carbon fiber road bikes got good enough/cheap enough for me to buy one.

I think people underestimate incremental improvements, 4% (arbitrarily) a year, year on year adds up eventually.

Look at the improvements to Li-Ion battery technology as a good example.

Recently I've been doing research on a programming problem that has come up at the new job, I pulled the related research and the canonical first representation of the problem on a computer was formulated in 1966 and the issues it addressed in the paper are identical to the way the processes are run at new employer, almost word for word.

51 years that research has existed and they are still doing things the way they did then.

> Recently I've been doing research on a programming problem that has come up at the new job, I pulled the related research and the canonical first representation of the problem on a computer was formulated in 1966 and the issues it addressed in the paper are identical to the way the processes are run at new employer, almost word for word.

Computing is weirdly ahistorical. Hardly anyone ever looks at the research; everyone prefers to invent it themselves.

Absolutely, doing a deep dive into the material has been fascinating, you can see the approaches evolve as hardware got faster.

My math level isn't quite there for some of it but the problem had been studied hugely and there are some good 'field guide' level references out there.

Its made me consider going back into education to do maths though. I don't like that I don't grok everything and with practical applications I'm actually excited by the maths.

> Its made me consider going back into education to do maths though... I'm actually excited by the maths.

Warning: One of two things will probably happen if you go back to (grad) school for math. Either you'll lose enthusiasm in the first year or two because you really love building stuff and miss it, or else you'll find you really do love the math and spend the rest of your life at a blackboard :)

What field of CS is this, if you don't mind me asking?

Flow shop scheduling, its a bunch of different approaches to optimising a seemingly simple problem (at first glance) that turns out to be np-hard at second glance.

The more I read the greater the complexity, I've never been much on the theory side and frankly as an enterprise programmer I've never really had to be, my distant A-level math has always been enough.

https://en.m.wikipedia.org/wiki/Flow_shop_scheduling

Its a practical application of some really beautiful approaches to a problem (everything from simple queue stuff through to genetic algorthithms and machine learning) I didn't know existed and at the same time a decent solution will have a really big impact on the business I work for.

It might take me quite a while to grasp even a small chunk though I'm starting from a pretty low level.

I'm not the parent poster, but for me it's confidential computing. I'm in the same boat, though I do have a B.Sci in Mathematics which helps!

articles always overhype these types of advances. Specifically in materials science, they ignore:

1. ease of synthesis. Many of the cool materials with nice properties you read about in these articles cannot yet be produced easily at scale, at requisite purity, and cheaply. Tying in to...

2. cost. Even when new materials are strictly better than widely used ones, they can still go nowhere. Obvious but everyone seems to forget this.

Yes. I feel like cancer has been cured every few weeks since Reddit first went live.

Cancer is easy to kill. The hard part is not killing the human around the cancer as well.

Add to this that there are many, many different types of cancer. There won't ever be a cure for cancer. We may find a cure for a cancer, but there are many types of cancer.

A good friend is an oncologist. He kinda hates it when people talk about a cure for cancer. I guess it just doesn't work that way.

I think the problem is the nanocrystals are about 500 nm long, of the order of 100th the width of a human hair, so it's hard actually build much with them. From another article:

>Calculations using precise models based on the atomic structure of cellulose show the crystals have a stiffness of 206 gigapascals

>"It is very difficult to measure the properties of these crystals experimentally because they are really tiny," Zavattieri said. "For the first time, we predicted their properties using quantum mechanics." (https://phys.org/news/2013-12-cellulose-nanocrystals-green-m... )

So they are strong in theory but too small to actually pull on the ends.

There's some recent research mixing them in 3d printer inks http://www.3ders.org/articles/20170531-empa-researchers-deve...

They can also be electrospun into fibers.

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.

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.

Well, the material in question degrades badly in contact with water.

If they know about it and have suppliers .. otherwise they'd stick to CF by network effect.

Pulp can move, baby!

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

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.

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.

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.

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.

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

> 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).

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...

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.

One problem with UHMWPE is it's slippery, so hard to glue to a rigid composite.

Also, don't count out the path dependence of even very competitive industries. They know carbon fiber, so that's what they use, and they then make small increments from their known territory.

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

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