15 ms·

This seems to be the research behind it: https://www.fpl.fs.usda.gov/documnts/pdf2018/fpl_2018_song001.pdf https://www.fpl.fs.usda.gov/documnts/pdf2018/fpl_2018

This seems to be the research behind it: https://www.fpl.fs.usda.gov/documnts/pdf2018/fpl_2018_song001.pdf https://www.fpl.fs.usda.gov/documnts/pdf2018/fpl_2018_song00... And there are only smaller comparisons towards steel. They are more focused on how it compares to regular wood. In summary, what they are doing: 1. Boil the wood. 2. Press the wood. 3. Done.

kragen 1y ago
Liangbing Hu at UMD, checks out. Fantastic find! This should at least be the top comment on this thread to offset the content-free journalist pablum that's linked. The strength is 483–587 MPa, I seem to see when skimming, which is indeed superior to ASTM A36 structural steel (250MPa yield strength). In Extended Data Figure 1c, they reported the density as 1.3g/cc, a sixth of the density of steel. (Extended data figure 2f plots density against lignin removal percentage.) Of course high-strength steels are stronger, but not six times stronger. As for the process, they didn't just boil the wood; they boiled it with lye (2.5M, the "food industry chemical") and sodium sulfite (0.4M, technically also a food industry chemical, used for example as an antioxidant in wine) for 7 hours before densifying it with 5MPa for "about a day", removing optimally 45% of the lignin. This is similar to the sulfite chemical wood pulping process that preceded the Kraft paper process, just carried out at high pH and not taken to completion, so in a sense I guess the result is sort of like Masonite, which is also made from cellulose fibers from wood bonded with the wood's natural lignin. Environmental concerns may be an obstacle; sulfite pulping is nasty. Also presumably to mass-produce the stuff they'll want to find ways to shorten the cycle time, and maybe already have. The burning question that arises in my mind is why nobody was doing this in 01890, 135 years ago. Sulfite pulping was going gangbusters, building materials were booming, environmental concerns were largely unknown, and there was a rage for everything newfangled, modern, and "scientific". The scientific discipline of strength of materials, needed to calculate the benefits, was already well developed. Mason put Masonite into mass production in 01929, with a process involving autoclaving wood chips at 2800kPa. So what prevented someone from selling Superwood back then? Did nobody try partial alkaline sulfite pulping and pressing the result?
- calmbonsai 1y ago
  [flagged]
- littlestymaar 1y ago
  The antibacterial properties of penicillin had been discovered many times before it was eventually realized what a big deal it was in 1940 (Howard Florey's role is much more important than Flemings' for that reason). So it's entirely possible that the process was found, and discarded straight away because they didn't realize how cool their invention was.
  - kragen 1y ago
    That's one possibility. Another is that it has a critical drawback; Masonite siding resulted in a massive class-action lawsuit verdict due to moisture damage (though the researchers say Superwood is less vulnerable) and it occurs to me that maybe structural steel's plastic deformation when overloaded as a construction material is somewhat more forgiving than the brittle fracture behavior typical of wood and evident in the photos of their ballistic testing.
    - littlestymaar 1y ago
      That it has a fatal flaw is indeed a possibility, but I don't think it could be the reason why it hasn't been invented sooner: if anything, we are detecting these kinds of flaws way faster than we used to, so it's likely that in the past it would have been produced at scale long before we found the problem, and given that consumer laws were nonexistent back then, it could have been kept on the market long after the flaw had been found, as long as it is economical enough to produce.
    - rascul 1y ago
      I've worked with masonite too many times. That stuff is garbage and doesn't belong anywhere near a house.
- permo-w 1y ago
  why are you making the choice to place leading zeroes on your years?
tapia 1y ago
If that is the case, then I don't see any novelty here. This has been done for a long time. In Germany, this is called "Panzerholz" (something like "bulletproof wood")
- mml 1y ago
  "armor wood"
- brador 1y ago
  Why isn’t panzerholz wood used everywhere? What is the article missing?
  - WJW 1y ago
    Same reason we don't build bridges out of titanium: panzerholz is more expensive than normal wood, and normal wood is good enough for most applications where it's used.
    - chronogram 1y ago
      Titanium's strength is in its weight: steel's Young modulus is almost twice as high, so you'd have to build rather large bridges to compensate. Titanium is useful where weight is a concern, like things you launch into space. Steel is perfect whenever weight isn't a concern and sometimes still works really well because you get so much strength out of so little which is why there are so many fans of the thin, shock absorbing, steel bike frames.
      - Maarten88 1y ago
        Titanium's advantage is imo not so much its weight, as aluminium is better still in that respect. Titanium is mostly better where corrosion and temperature resistance are important. Relative to weight, high grade steel, titanium and aluminium are about equal in tensile strength.
        1y ago
enopod_ 1y ago
This seems to be the original research paper: https://www.nature.com/articles/nature25476 https://www.nature.com/articles/nature25476 [edit: whoops, it's the same paper] "First, natural wood blocks were immersed in a boiling aqueous solution of mixed 2.5 M NaOH and 0.4 M Na2SO3 for 7 h, followed by immersion in boiling deionized water several times to remove the chemicals. Next, the wood blocks were pressed at 100 °C under a pressure of about 5 MPa for about 1 day to obtain the densified wood" Pretty simple and straightforward.
- IgorPartola 1y ago
  So what size will a 2x4 be after that? 0.75x1.25 just doesn’t roll off the tongue, does it? In seriousness, nominal vs actual sizing is just terrible. Do places outside of North America do this too?
  - dopidopHN 1y ago
    [flagged]
    - supermatt 1y ago
      > I never saw a house made a wood beside a ski chalet before Maybe you need to get out more? In France (where I assume you live) new public buildings are mandated to be at least 50% wood or other bio-based renewables. Also ~5% (and increasing) of new domestic builds are timber framed.
      - lukan 1y ago
        Is stone not a bio based renewable? (Concrete isn't, but plain old stone? Or bricks?)
        soulofmischief 1y ago
        Where are we growing new stones?
moffkalast 1y ago
That seems to really only provide benefits in use cases where weight isn't an issue, since this is conceptually just taking out air and adding more wood into the same amount of space to increase strength. Correct me if I'm wrong, but almost all use cases for wood rely on it to be somewhat light, for which the lattice structure is already fairly ideal.
- kragen 1y ago
  No, density is doubled, but strength is increased 11×, according to the paper. Sandwich panels with strong, stiff face sheets will always beat relatively homogeneous material like natural wood for the kinds of applications you are talking about.
  - moffkalast 1y ago
    Oh interesting, then it laminating thin sheets of this should be far lighter for the same strength, I didn't expect the strength increase to be anywhere near 2x much less 11x.
scythe 1y ago
Steel, itself, is a material with a wide range of properties. In terms of tensile strength, which is the simplest kind of strength to measure, steel ranges from mild steel at 400 N/mm^2 to piano wire alloys at about 2500 N/mm^2. "Stronger than steel" is a flashy appellation that usually means you have just reached the bottom end. A similar phenomenon occurs sometimes in papers about ceramics research. A very tough ceramic will often see a comparison of its fracture toughness to that of aluminium; as you've guessed, this usually refers to the toughness of pure unalloyed aluminium.
sharpshadow 1y ago
There was a inventor in Germany which got featured in a science show on television, which did something similar. He build a big pressure cooker where he placed the wood and a liquid mixture inside and let it cook for many hours. The wood got soak through completely, which gave it, as he claimed, resistance against rotting at every layer. For outdoor appliances the wood would not need any coating and not deteriorate. There was no mention about the hardness, but he also didn’t press it.
- jefb 1y ago
  Pressure treated wood is a very common outdoor building material.
- rajnathani 1y ago
  InventWood's research paper mentions not just boiling, but boiling it with an "aqueous mixture of NaOH and Na2SO3", which also helps with "partial removal of lignin and hemicellulose".
aitchnyu 1y ago
Can this make, say, planks out of sawdust?
- accrual 1y ago
  This is kind of how plywood is made - take wood chips and glue and press them together. I feel it wouldn't work well with sawdust, even with the chemical and heat+pressure process, since there would be little natural cohesion between the particles (larger pieces = more strength, up until you have entire logs/boards).
  - moron4hire 1y ago
    Large chips glued together is Oriented Strand Board (OSB). Small chips glued together is Particle Board. Sawdust glued together is Medium Density Fiberboard (MDF). Plywood is layers of veneer--thin sheets of wood--glued together in alternating orientations. Plywood can be nice. It doesn't expand with temperature changes like planks and doesn't have a grain direction that it can split along. The others, I hate. Any small amount of moisture and they delaminate. OSB is so ugly and rough that you need to hide it because you'll never be able to apply enough primer to cover the chip pattern. I'd rather just use regular plywood at that point. Particle board is the same, but I'm okay with the kind coated on both sides with melamine. It's pretty hard to get a much flatter surface than melamine particle board without spending ridiculously more on granite. But MDF is the worst. A lot of people like MDF because it's easy to work and can be fairly structural, if you use it right. But it's very, very easy to damage, has absolutely zero edge strength, and it makes a super-fine, extremely carcinogenic sawdust that is extremely difficult to clean up completely. Yes, all sawdust is carcinogenic, always wear a mask in the wood shop, but MDF sawdust never goes away. Frankly, it's just easier to get a bunch of sheets of birch plywood and southern pine dimensional lumber shipped direct to my house and not worry about it.
  - dodslaser 1y ago
    That would be fiberboard, not plywood. Plywood is "plies" of wood veneer layered perpendicularly (cross-grained) to improve dimensional stability.
  - deleted 1y ago
wolfi1 1y ago
in Finland they seem to have a similar method, where they bake the wood (they don't press it), the wood is then stable against rot and pests. please note: don't experiment with your oven at home, it will be unusable afterwards (because of the evaporating resins)
- jorts 1y ago
  Heat treated wood is used in the US as well. I’ve seen heat treated ash used for exterior purposes.
fho 1y ago
I would have thought that they remove the Lignin and replaced it with a (structurally better) resin.

kragen 1y ago

Liangbing Hu at UMD, checks out. Fantastic find! This should at least be the top comment on this thread to offset the content-free journalist pablum that's linked. The strength is 483–587 MPa, I seem to see when skimming, which is indeed superior to ASTM A36 structural steel (250MPa yield strength). In Extended Data Figure 1c, they reported the density as 1.3g/cc, a sixth of the density of steel. (Extended data figure 2f plots density against lignin removal percentage.) Of course high-strength steels are stronger, but not six times stronger. As for the process, they didn't just boil the wood; they boiled it with lye (2.5M, the "food industry chemical") and sodium sulfite (0.4M, technically also a food industry chemical, used for example as an antioxidant in wine) for 7 hours before densifying it with 5MPa for "about a day", removing optimally 45% of the lignin. This is similar to the sulfite chemical wood pulping process that preceded the Kraft paper process, just carried out at high pH and not taken to completion, so in a sense I guess the result is sort of like Masonite, which is also made from cellulose fibers from wood bonded with the wood's natural lignin. Environmental concerns may be an obstacle; sulfite pulping is nasty. Also presumably to mass-produce the stuff they'll want to find ways to shorten the cycle time, and maybe already have. The burning question that arises in my mind is why nobody was doing this in 01890, 135 years ago. Sulfite pulping was going gangbusters, building materials were booming, environmental concerns were largely unknown, and there was a rage for everything newfangled, modern, and "scientific". The scientific discipline of strength of materials, needed to calculate the benefits, was already well developed. Mason put Masonite into mass production in 01929, with a process involving autoclaving wood chips at 2800kPa. So what prevented someone from selling Superwood back then? Did nobody try partial alkaline sulfite pulping and pressing the result?

calmbonsai 1y ago
[flagged]
littlestymaar 1y ago
The antibacterial properties of penicillin had been discovered many times before it was eventually realized what a big deal it was in 1940 (Howard Florey's role is much more important than Flemings' for that reason). So it's entirely possible that the process was found, and discarded straight away because they didn't realize how cool their invention was.
- kragen 1y ago
  That's one possibility. Another is that it has a critical drawback; Masonite siding resulted in a massive class-action lawsuit verdict due to moisture damage (though the researchers say Superwood is less vulnerable) and it occurs to me that maybe structural steel's plastic deformation when overloaded as a construction material is somewhat more forgiving than the brittle fracture behavior typical of wood and evident in the photos of their ballistic testing.
  - littlestymaar 1y ago
    That it has a fatal flaw is indeed a possibility, but I don't think it could be the reason why it hasn't been invented sooner: if anything, we are detecting these kinds of flaws way faster than we used to, so it's likely that in the past it would have been produced at scale long before we found the problem, and given that consumer laws were nonexistent back then, it could have been kept on the market long after the flaw had been found, as long as it is economical enough to produce.
  - rascul 1y ago
    I've worked with masonite too many times. That stuff is garbage and doesn't belong anywhere near a house.
permo-w 1y ago
why are you making the choice to place leading zeroes on your years?

tapia 1y ago

If that is the case, then I don't see any novelty here. This has been done for a long time. In Germany, this is called "Panzerholz" (something like "bulletproof wood")

mml 1y ago
"armor wood"
brador 1y ago
Why isn’t panzerholz wood used everywhere? What is the article missing?
- WJW 1y ago
  Same reason we don't build bridges out of titanium: panzerholz is more expensive than normal wood, and normal wood is good enough for most applications where it's used.
  - chronogram 1y ago
    Titanium's strength is in its weight: steel's Young modulus is almost twice as high, so you'd have to build rather large bridges to compensate. Titanium is useful where weight is a concern, like things you launch into space. Steel is perfect whenever weight isn't a concern and sometimes still works really well because you get so much strength out of so little which is why there are so many fans of the thin, shock absorbing, steel bike frames.
    - Maarten88 1y ago
      Titanium's advantage is imo not so much its weight, as aluminium is better still in that respect. Titanium is mostly better where corrosion and temperature resistance are important. Relative to weight, high grade steel, titanium and aluminium are about equal in tensile strength.
      - 1y ago

enopod_ 1y ago

This seems to be the original research paper: https://www.nature.com/articles/nature25476 https://www.nature.com/articles/nature25476 [edit: whoops, it's the same paper] "First, natural wood blocks were immersed in a boiling aqueous solution of mixed 2.5 M NaOH and 0.4 M Na2SO3 for 7 h, followed by immersion in boiling deionized water several times to remove the chemicals. Next, the wood blocks were pressed at 100 °C under a pressure of about 5 MPa for about 1 day to obtain the densified wood" Pretty simple and straightforward.

IgorPartola 1y ago
So what size will a 2x4 be after that? 0.75x1.25 just doesn’t roll off the tongue, does it? In seriousness, nominal vs actual sizing is just terrible. Do places outside of North America do this too?
- dopidopHN 1y ago
  [flagged]
  - supermatt 1y ago
    > I never saw a house made a wood beside a ski chalet before Maybe you need to get out more? In France (where I assume you live) new public buildings are mandated to be at least 50% wood or other bio-based renewables. Also ~5% (and increasing) of new domestic builds are timber framed.
    - lukan 1y ago
      Is stone not a bio based renewable? (Concrete isn't, but plain old stone? Or bricks?)
      - soulofmischief 1y ago
        Where are we growing new stones?

moffkalast 1y ago

That seems to really only provide benefits in use cases where weight isn't an issue, since this is conceptually just taking out air and adding more wood into the same amount of space to increase strength. Correct me if I'm wrong, but almost all use cases for wood rely on it to be somewhat light, for which the lattice structure is already fairly ideal.

kragen 1y ago
No, density is doubled, but strength is increased 11×, according to the paper. Sandwich panels with strong, stiff face sheets will always beat relatively homogeneous material like natural wood for the kinds of applications you are talking about.
- moffkalast 1y ago
  Oh interesting, then it laminating thin sheets of this should be far lighter for the same strength, I didn't expect the strength increase to be anywhere near 2x much less 11x.

scythe 1y ago

Steel, itself, is a material with a wide range of properties. In terms of tensile strength, which is the simplest kind of strength to measure, steel ranges from mild steel at 400 N/mm^2 to piano wire alloys at about 2500 N/mm^2. "Stronger than steel" is a flashy appellation that usually means you have just reached the bottom end. A similar phenomenon occurs sometimes in papers about ceramics research. A very tough ceramic will often see a comparison of its fracture toughness to that of aluminium; as you've guessed, this usually refers to the toughness of pure unalloyed aluminium.

sharpshadow 1y ago

There was a inventor in Germany which got featured in a science show on television, which did something similar. He build a big pressure cooker where he placed the wood and a liquid mixture inside and let it cook for many hours. The wood got soak through completely, which gave it, as he claimed, resistance against rotting at every layer. For outdoor appliances the wood would not need any coating and not deteriorate. There was no mention about the hardness, but he also didn’t press it.

jefb 1y ago
Pressure treated wood is a very common outdoor building material.
rajnathani 1y ago
InventWood's research paper mentions not just boiling, but boiling it with an "aqueous mixture of NaOH and Na2SO3", which also helps with "partial removal of lignin and hemicellulose".

aitchnyu 1y ago

Can this make, say, planks out of sawdust?

accrual 1y ago
This is kind of how plywood is made - take wood chips and glue and press them together. I feel it wouldn't work well with sawdust, even with the chemical and heat+pressure process, since there would be little natural cohesion between the particles (larger pieces = more strength, up until you have entire logs/boards).
- moron4hire 1y ago
  Large chips glued together is Oriented Strand Board (OSB). Small chips glued together is Particle Board. Sawdust glued together is Medium Density Fiberboard (MDF). Plywood is layers of veneer--thin sheets of wood--glued together in alternating orientations. Plywood can be nice. It doesn't expand with temperature changes like planks and doesn't have a grain direction that it can split along. The others, I hate. Any small amount of moisture and they delaminate. OSB is so ugly and rough that you need to hide it because you'll never be able to apply enough primer to cover the chip pattern. I'd rather just use regular plywood at that point. Particle board is the same, but I'm okay with the kind coated on both sides with melamine. It's pretty hard to get a much flatter surface than melamine particle board without spending ridiculously more on granite. But MDF is the worst. A lot of people like MDF because it's easy to work and can be fairly structural, if you use it right. But it's very, very easy to damage, has absolutely zero edge strength, and it makes a super-fine, extremely carcinogenic sawdust that is extremely difficult to clean up completely. Yes, all sawdust is carcinogenic, always wear a mask in the wood shop, but MDF sawdust never goes away. Frankly, it's just easier to get a bunch of sheets of birch plywood and southern pine dimensional lumber shipped direct to my house and not worry about it.
- dodslaser 1y ago
  That would be fiberboard, not plywood. Plywood is "plies" of wood veneer layered perpendicularly (cross-grained) to improve dimensional stability.
- deleted 1y ago

wolfi1 1y ago

in Finland they seem to have a similar method, where they bake the wood (they don't press it), the wood is then stable against rot and pests. please note: don't experiment with your oven at home, it will be unusable afterwards (because of the evaporating resins)

jorts 1y ago
Heat treated wood is used in the US as well. I’ve seen heat treated ash used for exterior purposes.

fho 1y ago

I would have thought that they remove the Lignin and replaced it with a (structurally better) resin.