Report by Jacopo Prisco, CNN:
The material “is much stronger and better than wood in practically every aspect we tested,” say the scientists.
A U.S. company has developed a new type of wood that it claims has up to 10 times the strength-to-weight ratio of steel, while being up to six times lighter.
Called “Superwood,” the product has just been commercially launched by InventWood, a company co-founded by materials scientist Liangbing Hu.
More than a decade ago, Hu embarked on a mission to reinvent one of humanity’s oldest known building materials. While working at the Center for Materials Innovation at the University of Maryland, Hu — now a professor at Yale — found innovative ways to redesign wood. He even made it transparent by removing part of one of its main components, lignin, which gives wood its color and part of its strength.
His true goal, however, was to make wood stronger, using cellulose, the main component of plant fiber and “the most abundant biopolymer on the planet,” according to Hu.
The breakthrough came in 2017, when Hu first strengthened ordinary wood by chemically treating it to enhance its natural cellulose, turning it into a better building material.
The wood was first boiled in a bath of water and selected chemicals, then hot-pressed so it collapsed at the cellular level, making it significantly denser. After the week-long process, the resulting wood showed a strength-to-weight ratio “superior to that of most metals and structural alloys,” according to the study published in Nature.
Now, after years of refining the process and filing more than 140 patents, Superwood has been commercially launched.
“From a chemical and practical standpoint, it’s wood,” explained InventWood CEO Alex Lau, who joined the company in 2021. In buildings, this could allow structures potentially up to four times lighter than current ones, Lau said — meaning they would be more resistant to earthquakes, easier on foundations, and faster and simpler to build.
“It looks like wood and, when you test it, it behaves like wood,” Lau added, “except that it’s much stronger and better than wood in virtually every aspect we tested.”
Competing with steel?
InventWood is manufacturing Superwood at its plant in Frederick, Maryland, and while production time is now measured in hours rather than days, scaling up will take some time, Lau said.
Initially, the company plans to focus on outdoor applications such as decks and cladding, before moving on to indoor uses like wall panels, flooring, and residential furniture next year.
“People always complain that furniture breaks over time, and that usually happens because it bends or breaks at the joints — which are currently made of metal because regular wood isn’t strong enough,” Lau said. Superwood could replace those parts, he added, as well as screws, nails, and other metal fasteners.
Eventually, Lau envisions an entire building constructed from Superwood, though that will require further testing.
As in Hu’s original experiment, the wood is strengthened through a chemical process that alters the cellulose structure and is compressed under great force, preventing it from returning to its original shape. “In theory, we can use any kind of wood material,” said Lau. “In practice, we’ve tested 19 different types of wood, plus bamboo — and it worked with all of them.”
InventWood claims Superwood is up to 20 times stronger than regular wood and up to 10 times more dent-resistant, since the wood’s natural porous structure has been collapsed and hardened. This makes it immune to fungi and insects. It also earns the highest rating in standard fire-resistance tests.
Currently, Superwood costs more than regular wood and has a higher manufacturing carbon footprint, but Lau said that compared with steel production, its carbon emissions are 90% lower.
He added that the goal “is not to be cheaper than wood, but to be competitive with steel” as production scales up.
The wood trend
Other forms of engineered wood have long existed as construction materials, but InventWood says those are simply rearranged pieces of wood held together by adhesives, rather than wood that has been transformed at the molecular level — like Superwood.
Fonte: https://www.cnnbrasil.com.br
