New “Super Wood” Could Rival Steel and Titanium Alloys
March 7, 2018
Newly Developed “Super Wood” Could Rival Steel and Titanium Alloys
Two-step process alters wood’s density, increasing its strength tenfold
Researchers at the University of Maryland’s James Clark School of Engineering, under the direction of team co-leaders Teng Li and Liangbing Hu, have discovered a way to transform ordinary wood into “super wood” – so-called because of its exceptional strength. Speaking about the properties of the material, Teng Li claims, “It takes 10 times more energy to fracture than natural wood. It is as strong as steel, but six times lighter.”
This modified wood shows potential as a promising substitute for steel, in particular. “It's comparable to carbon fiber, but much less expensive," according to Liangbing Hu. Plus, “It can even be bent and molded at the beginning of the process,” adds Teng Li.
Another advantage of super wood is its sustainability. Hu points out, “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 buildings.”
The process the research team devised to create this super-strong wood involves boiling wood in a mixture of sodium hydroxide (an inorganic compound also known as lye or caustic soda) and sodium sulfite (a soluble sodium salt of sulfurous acid) to partially remove hemicellulose and lignin, which add rigidity to cell walls in wood. Next, the wood is subjected to heat and mechanical pressure – a process known as hot pressing – to crush the wood’s cellular walls and to create in their stead ultra-strong nanofibers.
It’s these fibers - with diameters equal to one billionth of a meter – that provide superior strength and resistance to make this wood “super.” In a test designed to measure resistance, projectiles were fired into two wood samples – one natural wood sample and one modified wood sample. Whereas the projectile shot into the natural wood sample flew right through it, the projectile fired into the super wood did not exit it.
In the decades ahead, it’s likely that super wood will replace many different types of material used in the transportation and construction industries, including natural wood. Asked whether she anticipates a shift from natural to super wood in the construction of custom wood countertops, which account for the lion’s share of sales for her employer, Butcher Block Co., Kathleen Grodsky, the company’s Marketing VP, expressed skepticism. “While hardness is an important factor to consider when choosing a countertop material, aesthetics is far and away a more important criterion,” she explained. “More than anything, consumers select wood for their countertops because of its coloration and grain patterns. While super wood provides superior strength, it’s hard to imagine much demand for wood that has been boiled and compressed.”
For more information, please visit Butcher Block Co.
Name: Kathleen Grodsky
Organization: Butcher Block Co.
Address: 10448 N 21st Pl Phoenix, Arizona 85028
Phone: (877) 845-5597