Subject: Superwood
https://edition.cnn.com/scienc...

Maryland-based InventWood has created a high-strength “Superwood.”

A US company has engineered a new type of wood that it says has up to 10 times the strength-to-weight ratio of steel, while also being up to six times lighter.

“Superwood” has just launched as a commercial product, manufactured by InventWood, a company co-founded by material scientist Liangbing Hu.

“It looks just like wood, and when you test it, it behaves like wood,” Lau added, “except it’s much stronger and better than wood in pretty much every aspect that we’ve tested.”

The wood was first boiled in a bath of water and selected chemicals, then hot-pressed to collapse it at the cellular level, making it significantly denser. At the end of the weeklong process, the resulting wood had a strength-to-weight ratio “higher than that of most structural metals and alloys,” according to the study published in the journal Nature.

Much like in Hu’s original experiment, the wood is strengthened via a chemical process that alters the basic structure of the cellulose and is compressed very tightly without springing back. “In theory, we can use any kind of wooden material,” Lau said. “In practice, we’ve tested with 19 different kinds of species of wood as well as bamboo, and it’s worked on all of them.”

InventWood says Superwood is up to 20 times stronger than regular wood and up to 10 times more resistant to dents, because the natural porous structure of the wood has been collapsed and toughened. That makes it impervious to fungi and insects. It also gets the highest rating in standard fire resistance tests.

Superwood currently costs more than regular wood and also has a larger manufacturing carbon footprint, but Lau said that compared to steel manufacturing, the carbon emissions are 90% lower.

Other types of engineered wood have existed as construction materials for a long time, but InventWood says that these are simply rearranged pieces of wood that are held together with adhesives, rather than wood that has been altered at the molecular level like Superwood. He added that the target is “not to be cheaper than wood, but to be competitive with steel,” when manufacturing scales up.

Initially, the company plans to focus on external applications such as decking and cladding, before moving on to internal applications such as wall paneling, flooring and home furniture sometime next year.

“Wood products can be considered a long-term carbon storage system, and construction with wood could see our cities ‘lock in’ carbon emission in buildings for long periods of time.” “The barrier to more timber buildings isn’t really the need for more strength, it’s that the construction industry is risk averse and slow to change.”

Jeff