Maryland University Engineers found a way to make wood more than ten times more stronger, creating an inexpensive and easy alternative to most metals and alloys.
Durable materials are now, as a rule, expensive, require mining, complex production processes and high energy costs. Therefore, technology processing cheap and environmentally friendly wood continue to improve. However, the existing methods of increasing the density of natural material do not allow to achieve the necessary indicators.
The team of American engineers presented new wood compression technology up to 20% of its original thickness, which allows you to completely get rid of emptiness and partly from natural glue (hemicellulose and lignin). For this, the material is first boiled in a solution of NaOH / Na2SO3, which makes it more porous and flexible, and then pressed perpendicular to the growth direction at 100 ° C. In this case, the cellulose remains untouched, and the hydrogen bond between the closely located microscopic fibers additionally enhances the strength.
The slow motion of how compacted wood stops a cylindrical bullet.
The wood compacted in this way may slightly swell and lose its density under conditions of 95% humidity, but oil-based coating completely solves this problem. The tests have shown that the indicators of the strength of the material are not inferior to steel, but its mass is 6 times less. It can even be bent, and for destruction takes 10 times more energy than for ordinary tree.
According to the developers, such wood in terms of reliability and durability is capable of competing with most metals and even titanium alloys or carbon. They plan to commercialize the invention through the subsidiary of Inventwood and argue that the material will soon be able to replace steel in cars, airplanes, sea containers and buildings.
Swiss scientists also developed a unique