Wood for Aircraft Construction
University of Maryland engineers have found a way to make wood more than ten times stronger by creating an inexpensive, lightweight alternative to most metals and alloys..
Durable materials are now generally expensive, require mining, complex manufacturing processes, and high energy costs. Therefore, technologies for processing cheap and environmentally friendly wood continue to be improved. However, the existing methods for increasing the density of natural material do not allow achieving the required indicators..
A team of American engineers presented a new technology for compressing wood to 20% of its original thickness, which allows you to completely get rid of voids and partly from natural glue (hemicellulose and lignin). For this, the material is first boiled in a NaOH / Na2SO3 solution, which makes it more porous and flexible, and then pressed perpendicular to the growth direction at a temperature of 100 °C. At the same time, the cellulose remains intact, and the hydrogen bond between its closely spaced microscopic fibers further enhances the strength.
Time-lapse footage of compacted wood stopping a cylindrical bullet.
Wood compacted in this way can swell slightly and lose its density in 95% humidity conditions, but an oil-based coating completely solves this problem. Tests have shown that the strength indicators of the material are not inferior to steel, but its weight is 6 times less. It can even be bent, and it takes 10 times more energy to shatter than a regular tree..
According to the developers, In terms of reliability and durability, such wood can compete with most metals and even titanium alloys or carbon fiber. They plan to commercialize the invention through subsidiary Inventwood and argue that the material could soon replace steel in cars, airplanes, shipping containers and buildings..
Swiss scientists have also developed a unique porous material that is able to quickly recover residual gold from sea water, fresh water, waste water, as well as sludge and complex solutions..
text: Ilya Bauer, photo: clipgoo, thechemicalengineer