Toyota Setusma wooden concept car

With the signing of the Paris Climate Agreement, the risks posed by climate change are in sharper focus than ever before.

In order to achieve the target of keeping the average global temperature increase from pre-industrial times below 1.5 degrees, there must be step changes in the way industry operates. For example, one study estimates that in order to cut emissions sufficiently the building sector as a whole must become carbon neutral by 2020, and automakers must increase  electric vehicle sales to around 20% over the next 2 years.

These might sound like impossible feats, especially given the inertia of the lumbering giants of heavy industry. But what if material innovation could provide some of the answers.

Organic materials such as wood harbour tremendous opportunities. Over the growth period of wood, carbon is absorbed into the physical structure of the material. This means that anything constructed from wood becomes a carbon storage vault, preventing CO2 from being released into the atmosphere.

In the construction industry, the facts are stark. Whilst concrete and steel have fantastic physical properties, their reputation in terms of environmental impact are less stellar. Concrete and steel production combined account for 8 percent of global greenhouse emissions. Wood in its raw form does not have the consistency in physical properties to be a suitable replacement in the 21st century. However advances in engineered wood technology now make it a viable option for the first time.

Render of world's tallest wood framed skyscraper planned for construction in Tokyo by Sumitomo Forestry
© Sumitomo Forestry

CLT, Glulam and Ply

Engineered wood have one central common factor. Simply put, they essentially take the raw material, process it into its smaller constituent parts, and then rearrange the pieces and stick them back together. This results in a stronger, dimensionally stable, cost effective material without being constrained to the original shape of the tree it was made from.

CLT is formed from layers of sawn planks, arranged in a tight, layered cross hatch. This gives it the ability to make load-bearing walls, floors and ceilings, without the need for a supporting substructure. CLT buildings can be manufactured offsite and then assembled at incredible speed, sometimes in a matter of days.

Glulam is also composed of sawn planks, but instead they are glued longitudinally to form beams. In addition to offering strength-to-weight ratio 10x better than steel beams, they also have no limit to manufactured length, allowing enormous design freedom.

Ply is layered from thin sheets which are peeled from a log on a continuous roll, almost akin to a giant pencil sharpener. Again the layers are arranged with an alternating grain direction. An uneven number of layers creates a balanced structure and prevents warping.

CLT coupled with other engineered wood materials have the potential to reduce our dependency on concrete and steel by around 80 percent. The benefits don’t stop above ground either. Once the main structure is replaced with wood, the overall weight of the construction is vastly reduced. This means that foundation can be shallower, so even though concrete still needs to be used, we can use less of it.

These materials are available to be used now, but looking towards the not-too-distant future, many more innovations are in the pipeline.

In Stockholm, scientists have created optically clear wood, by removing the lignin pigment which gives wood its natural colour. Thereby opening the possibility of windows or solar cells constructed from organic materials.

Once we start breaking wood down into its chemical components, the true scope of what could be possible is revealed. Nanocellulose, the main fibrous component of wood, is starting to be refined and used as an alternative to hydrocarbon materials in adhesives, paints, and other staples of manufacture.

Meanwhile in the car industry, Toyota are already showing their interest in the engineering potential of wood, with the admittedly whimsical Setsuna. This open-top two-seater is just a concept for now, but underlines a more serious point. For the automotive industry, weight, cost as well as environmental impact are more important than ever.

Toyota Setusma wooden concept car with its body panels laid out on the floor
© Toyota

Steps are being taken to transition to low carbon propulsion methods, but manufacturers are also considering the impact higher up the chain. 22% of a car’s emissions are produced in the factory, before it’s driven a single mile. With its excellent environmental credentials, the new generation of wood products could provide part of the solution.

Current development by the University of Maryland of so-called ‘densified wood’ is yielding order-of-magnitude strength increases, compared with its raw form. To process the material, around 50 percent of the lignin is removed from the wood, and it is then compressed at high temperatures.

With a strength comparable to that of steel, but a fraction of the weight, the applications in the automotive and aerospace industries are obvious. So obvious in fact that the auto industry has just awarded the inventors $3.6 million to develop the material into a steel substitute for use in cars.

Similar densified wood materials are being used to create wooden versions of conventional fastenings. Densified wood bolts are already entering the market, used as fastenings in applications requiring non-inductance in the presence of  electromagnetic fields

A selection of bolt fastenings constructed from densified wood
© Roechling Industrial

At Cambian, we look forward to the future with optimism. Though our civilisation faces huge challenges ahead, we believe that looking to natural materials and using them to their full potential will provide an important part of the solution. If you are looking to start using more organic materials in your industry, and are looking for an engineering or manufacturing partner to facilitate that, contact Cambian today.

For further reading on the exciting future for wood, please check out the New Scientist article “Welcome to the New Age of Wood” which was a great inspiration for this piece.