Lumber is a material humans have been using for literally ages. It is strong, durable and quite easy to work with. The most important thing about wood is that we have a lot of it. It is a renewable resource and we can learn to use it sustainably. However, it is not really suitable for today‘s applications – it is just not strong enough for the structures we are creating now. Scientists from The University of Maryland decided to change that.
Wood is strong when used to build houses and furniture. But everyone knows that eventually it rots and it just cannot compare with steel. Wood parts crack under bending forces and thus are difficult to use in industrial setting. Steel is just so much more durable and can withstand the test of time with minimal maintenance. However, we can still improve lumber if we decide to do so. That is what scientists from The University of Maryland set out to do.
Lignin polymer gives wood its rigidity. It constitutes the structure that supports the tree against its own weight. However, scientists decided to remove lignin altogether. This may look like a strange step, since lignin is what makes the wood strong, but it did help scientists improve wood significantly. Removal of lignin made wood easier to treat under pressure in 65.5 degrees Celsius. This compressed the wood – cellulose fibres compressed together, making the material much denser. Even knots disappear during this process. Hydrogen bonds started forming giving the wood a lot of added toughness. Of course, the piece of wood became 5 times thinner, but also twelve times stronger than natural wood and ten times tougher. In fact, creators of this “super wood” believe that in some applications this material could compete with steel of even titanium alloys.
Scientists think that this stronger wood could be used in automotive and even aeroplane industries. They say that the material is comparable to carbon fibre, but much cheaper. It is light, durable and strong, but can it really compete with any sort of metal?
Metal is not juts strong – it is easy to work with. You can cast it into any shape you want. Furthermore, metal is consistent. If a company orders hundreds of steel sheets, it can be sure that they will be within tight margins of quality and strength. Wood is still a natural material, which varies quite a bit from piece to piece. You can also weld steel – how can you easily and quickly attach different pieces of wood? Wood glue comes to mind, but clamping and waiting is not acceptable in industrial environment. Wood also shrinks and expands with humidity changes, which also limits its applications.
Finally, steel leaves virtually no waste. Even smaller pieces can be melted to make new castings. Wood can only be machined and leaves a ton of sawdust. It doesn’t hurt the environment though, which could be a big advantage. We will have to wait and see where this invention leads to.