[enopod_]

This seems to be the original research paper: 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.

[scythe]

The real question for practical purposes is how much of these fine chemicals are actually consumed during the process and how much can be reused. The foul-smelling Kraft process has held on to its title in paper production because the chemicals it uses can be recycled within the plant itself. There are many better, less polluting ways to make paper, but they consume an impractical amount of chemicals which drives the price way out of economic usability.

This process will need to regenerate almost all of that sodium hydroxide and sodium sulfite, or it's just peracetic paper again.

[koverstreet]

I'd rather live next to a leaky paper plant than a teflon plant any day.

[itsbenweeks]

I wouldn't. The numerous miscarriages that my grandmother had while living in a mill town, and the cancer diagnoses that followed family who worked at the mill taught me to stay upstream of mill towns.

[gertop]

I think it's clear that you're not familiar with how often paper mills have poisoned the nearby populations.

[zoklet-enjoyer]

Visit Int'l Falls, MN. They have a paper mill and then there's another one on the other side of the river in Canada. It's foul

[echelon]

I'd rather live next to neither. Paper plants stink.

[Loughla]

Absolutely not. Paper mills are fucking nightmares.

[accrual]

I wonder if this can help offset the weakness of new growth wood - trees and wood specifically designed for fast growth and quick turn around.

https://brenthull.com/article/old-growth-wood

[the_sleaze_]

My thoughts as well. I was holding a board the other day and it just seemed, forgive me, aerosol-ized. Like those Aero chocolates that are essentially full of bubbles. "This new wood doesn't feel like wood used to" and shook my fist at the passing cloud.

I have high hopes for this product as a leg of sustainability.

[m463]

I wonder if it would work for bamboo.

[ksec]

My first thought as well. Considering they are the fastest growing plants. We cant stop the world from using steel or be carbon sensitive on things. But as soon as economics incentives kicks in we could decarbonise faster than most could imagine. I really hope timber technology improves to the point like solar where we would plant forest the size of a state.

[725686]

The problem that I see is that, if the thickness is so drastically reduced as in the video posted somewhere above, you will need (much, much) thicker wood to start with.

[turtlebits]

New growth wood is sustainable and is perfectly fine in construction, if you need strength, you can buy LSL/LVLs.

[hatsunearu]

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

Here's a NileRed video replicating the process.

[clayhacks]

Ok that was super cool to see. I can see how clearly the process described in the paper has plenty of room for improvement

[metalman]

There is a great deal of prior art in aviation and automotive engineering for densified wood, which have all proven to be non competitive with metal. Lighter, stronger, but not quickly adaptable to new designs or refinements.....the molds are large, complex, heavy, and expensive. And a simple no go for beams is that they(wood) burns and steel does not, will instantly remove them(wood) from bieng used in most building codes past a certain hight, where minimum times for evacuation durring a fire can not be met.

[bradknowles]

One of the reasons why Ipe (pronounced “e-pay”) wood is so fire resistant, is because of its density. You can get Class-A fire resistant Ipe that can be used to build in the Wildland/Urban Interface environment. Other woods like Teak and Rock Maple are also super dense, but I don’t know if you can get them in Class A ratings.

Now, Ipe is very expensive. I would hope this is less expensive than Ipe, and then the trick is to make your starting materials much larger, and being able to account for the shrinkage once the densification process has been completed.

You could also do laminates of this densified wood, in order to be able to use it for beams, plywood type functions, etc…. Or even fire resistant 2x4 boards.

[foota]

I was under the impression that mass timber buildings were actually safer for fires because it takes a very long time to burn through, and unlike steel they won't lose their strength in an intense fire.

[metalman]

what maters is time to escape befor "total involvement", or confaguration, steel contributes nothing to a fire, fire cant climb or follow it, and it acts as a heat sink, vs wood, which is fuel. All of the historical mass casualty fire storms, involved wooden structure, and steel, concrete,glass, and brick, ended that. Add in modern fire suppresion and fighting equipment and the current situation is quite secure vs/vs fire. edit, another factor is comunication and road infrastructure, where the recent fire storm in California, destroyed many many wooden structures, but the loss of life was exceptionaly low compared to other firestorms in less developed countrys. woods great, love the stuff, have a lot of wood, live in a wooden house and heat with wood, but there is essentialy no way that can be done with a thousand people in a huge building, so steel, which I also love and work with. Everything in it's place.

[bluGill]

"total involvement", or confaguration, is what matters true. However fires are more complex than that. Generally the wood frame isn't a source of fuel for the fire until later. The carpet and other furniture that is the same in all builds is likely to burn first. Not long after the wood frame is burning the steel frame absorbs enough heat to fail - but either way you really want to be out long before it gets that bad (and probably are dead if you are not)

[salynchnew]

> All of the historical mass casualty fire storms, involved wooden structure, and steel, concrete,glass, and brick, ended that.

You're right insofar as lots of improvements have been made to steel-and-concrete building fire safety since the 1970s. Plastics are sometimes still a problem.

https://en.wikipedia.org/wiki/Grenfell_Tower_fire

https://nfsa.org/2023/08/22/understanding-combustible-materi...

[IgorPartola]

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?

[imglorp]

It's true that dimensions are all screwy, evidently due to variable shrinkage during drying in the old days. The mills control for it now, but meanwhile everyone got used to the weird sizes and we're stuck with them because everyone centered on the shrunk sizes for tooling and standards. Pros know but it's a pain for DIYers.

https://www.inchcalculator.com/actual-size-of-dimensional-lu...

[lesuorac]

> It's true that dimensions are all screwy, evidently due to variable shrinkage during drying in the old days.

That's just an old wives tale.

Lumber shrinks for money reasons, older lumber is bigger [1] with sequential revisions to the standard decreasing it's real size [2] [3] (the difference between 2in and 15/8in in strength is minimal however you can keep doing that math, and they did, to go down from 2in to 1.5in over a century).

[1]: https://www.reddit.com/r/mildlyinteresting/comments/vv9atu/t...

[2]: https://ntrl.ntis.gov/NTRL/dashboard/searchResults/titleDeta...

[3]: https://www.synthmind.com/miscpub_6409.pdf

[bluGill]

Lumber shrinks, but not that much. There was NO standard and so mills just did what felt they could get away with calling a 2x4. Some mills did 2x4 was 2"x4", some did other sizes, it depending on how much they felt they could cheat vs how much they felt advertising the larger size would help. I have seen houses built in 1880 that used modern dimensions for 2x4s.

[PaulDavisThe1st]

This person claims otherwise:

https://www.youtube.com/watch?v=WaJFudED5FQ

They claim that the change was driven by railroad shipping charges, and wasn't based on drying, but on pre-planing the rough lumber to reduce shipping cost. They further claim that in 1919 the US Dept. of Agriculture studied the issue and ended up defining a national standard for what the post-planed dimensions of a 2x4 should be. And they further claim that it took until the early 1960s to settle on a new standard that matches what we use today.

[bluGill]

I've seen houses built in the late 1960s that used non-standard 2x4s, so I will dispute those facts. I don't remember details (and can't be bothered to look them up), but IIRC several different standards were tried before the current one finally took.

The pre-planing is a common claim, but I don't believe it. They can make lumber whatever size they want - of course they need to plane it, but they just make it larger to account for that. Still the planing excuse it one they like to use because it doesn't show "them" as trying to cheat us.

[not_a_bot_4sho]

> In seriousness, nominal vs actual sizing is just terrible. Do places outside of North America do this too?

I understand the origins of this. But I've never understood why we haven't moved on to actual sizing given the scale at which standardized lumber dimensions are produced

[bluGill]

I'm just glad there is a standard. It doesn't matter much what size it is. What matters is that I can go to any lumber yard/mill when I need more and get it. What matters is that I and my inspector can look at (or more likely memorize!) some charts and be sure that everything is strong enough. Is actually 2"x4" lumber stronger than the standard sizes - yes, but most of the time it doesn't matter, and if it does I really want to step up to 2x6 (or something) because margin of safety is important when you get that close)

[IrishTechie]

Definitely done in Ireland and the UK anyway.

[0x1ceb00da]

So I guess boiling and pressing will get rid of the trapped air inside wood and it won't work very well as an insulator?

[seniortaco]

Wood is already a poor insulator, so if it takes up less space and you can fit more insulation, that is better.

[jkmcf]

My uncle built his home from hardwood. No insulation. In sub freezing temps, you can put your hand in the wood and it isn't cold. Compared to my (poorly) insulated home, it b is significantly better.

[bluGill]

That isn't a good way to measure because the inside of the house is warming up the walls. Hardwood is a poor insulator, but it is an insulator. If you touch wood it will feel warm, but it still loses a lot of heat compared to a properly insulated wall.

[olddustytrail]

Hearing this reminds me of the Dara O' Briain line that American houses seem to have been built by the first two little pigs.

[Loughla]

Are the walls solid hardwood? Is it a cabin? How thick are the walls?

[dlubarov]

Yes, but if it's a much worse insulator, the extra heat transfer through studs might be more significant?

I'm not sure if it's been measured, but I imagine this densified wood would probably have at least twice the thermal conductivity of typical construction lumber, since naturally dense hardwoods already approach that.

So it seems like we'd basically need to replace 2x studs with 1x studs, assuming the same stud spacing, in order to match the thermal performance of a traditional wall.

I don't think this would be a dealbreaker at all though, one could always use continuous insulation instead of cavity insulation, which has a lot of benefits anyway. Maybe it can end up being a competitor to metal studs for commercial builds, at least.

[zip1234]

If this just replaces steel beams or allows more post frame construction, the walls wouldn't change. Actually, if used in post frame style construction, it would allow for more space for insulation with less thermal bridging.

[bluGill]

In modern construction we already put continuous insulation outside the 2x4 so that we don't have to deal with the studs and how much worse insulation they are.

[dlubarov]

I think that's the best practice, also for avoiding condensation, but isn't it pretty uncommon at least for residential builds in the US? Here in Washington, codes were recently changed to require continuous insulation, but I believe that's only with the prescriptive method. From what I've seen most builders seem to continue working around it and doing cavity insulation only.

[bluGill]

Depends on where you live, but that seems to be fairly common anyway in new builds.

[djtango]

Not a materials guy but would densified wood lead to such a drastic increase in thermal conductivity?

[dlubarov]

Air has very low thermal conductivity, so for a lot of materials, thermal conductivity is primarily a function of how much air they contain and how it's structured (ideally in tiny pockets to minimize heat transfer through convection). Like spray foams, fiberglass insulation, etc are basically designed to hold air while minimizing convection.

I believe that's somewhat true of woods as well - different woods seem to range from 0.12-0.25 W/(mK) or so, which is somewhat less conductive than the underlying compounds like cellulose (0.4), thanks to the trapped air in wood.

It seems like densifying wood would mitigate the insulation contribution of trapped air, causing thermal conductivity to approache that of the underlying compounds like cellulose, though I'm not sure exactly what those compounds are with their process and how close they get to that air-free extreme.

[8note]

if you dont make any other changes, it will have some detectable impact, but conductivity is linear with all of conductivity, depth, and area; and the other dimensions can also be changed like the screw diameter/pitch or the dimensions of the stud.

its very unlikely that this change will be an important consideration for house building or shopping though. theres simpler spots to reduce heat loss, like double paning your windows

[jolt42]

"poor insulator", seems like an odd statement, but it's all relative I suppose. It's certainly better than the masonry or steel that this will replace. But if you take the air pockets out of it, then it's not going to be as good, but likely better than steel.

[nemomarx]

You probably only use this wood for the frame, or spread through the rest of the wooden structures like rebar?

[gadflyinyoureye]

Wood used in framing has a small r value because of the air. The timber on the exterior prevents all the energy transfer.

The loss of r value can be off set with two 2x4 frames. As strong as a 2x6 wall and about the same price. Added benefit is air gaps.

[HWR_14]

Probably not. But it eliminates a lot of what makes wood flammable.

I wonder how it impacts the effects of humidity and time to make wood warp.

[heywoods]

Sounds like a great candidate for decking.