img(height="1" width="1" style="display:none" src="https://www.facebook.com/tr?id=2939831959404383&ev=PageView&noscript=1")

If you think this is hard...

Header Image

Words:
Stephen Cousins

Researchers produce compressed wood which is as strong as steel – but six times lighter

Ballistic test
Ballistic test

For once, news of bullets being fired isn't a cause for concern. This time it's researchers in lab coats at the University of Maryland that are firing at inanimate planks of wood. The University’s department of materials science has ‘battle-tested’ a new form of super-wood that is 12 times stronger than natural wood and 10 times tougher. They claim the substance is so strong, durable and cheap to produce that it could become a viable competitor to steel or even titanium alloys.

Using a ballistic air gun used to test the resistance of military vehicles, bullet-like projectiles were fired at five laminated layers of the material. These were stopped in their tracks, while those fired at natural wood passed through with relative ease. Teng Li, co-leader of the team, said in a statement: ‘It is both strong and tough, a combination not usually found in nature. It is as strong as steel, but six times lighter. It takes 10 times more energy to fracture than natural wood. It can even be bent and moulded at the beginning of the process.’ 

  • Densified wood
    Densified wood
  • Natural wood
    Natural wood
  • University of Maryland department of materials science co-leader Teng Li and assistant professor Liangbing Hu compare laboratory samples.
    University of Maryland department of materials science co-leader Teng Li and assistant professor Liangbing Hu compare laboratory samples.
123

The discovery, described in the latest edition of Nature magazine, involves a relatively straightforward treatment process. First the wood is boiled for seven hours in a bath of sodium hydroxide and sodium sulfite, to remove certain compounds that surround cellulose in the wood to create additional space within it. Then the block is then compressed at 100°C for an entire day to reduce it to one fifth of its original thickness and increase its density threefold.

The supreme strength is a result of crushing the cellulose tubes that bind the wood together to the point where they interlock. Scientists found it was crucial to remove approximately 45 percent of the compound lignin from the wood (a type of polymer that binds the cellulose) to prevent it from becoming too brittle and to achieve the correct density. The process will work on any kind of timber, potentially making softwoods more viable in construction.

Liangbing Hu, assistant professor at the department of materials science, said: ‘Soft woods like pine or balsa, which grow fast and are more environmentally friendly, could replace slower-growing but denser woods like teak – in furniture or in buildings.’

Latest

Steel is resilient, but fire still poses a risk. Specifying a frameless encasement system from a single manufacturer can help keep compliance and installation simple

Sourcing a frameless encasement system from a single manufacturer makes sense

A new BBA-certified membrane system is providing specifiers with a hydro-reactive and self-healing method of protecting underground structures

Discover the new hydro-reactive and self-healing product that protects underground structures

From working kitchens and tap displays to seminars and 'Grab and Go' samples, the RAK Ceramics' new Design Hub in Clerkenwell lets architects get hands-on with washroom products

RAK Ceramics opens London Design Hub

An innovative installation at Make architects' red brick HM Revenue & Customs offices in Salford manages the people flow with ease while providing a bold, spacious entrance

Innovative installations at Make's Three New Bailey, Salford

As well as having high embodied carbon, concrete is also draining the world's supplies of fine-grained sand. Now researchers have shown that recycled glass could provide a suitable replacement for 3D-printed buildings

With concrete production draining world supplies of fine-grained sand, recycled glass could provide a substitute