Why wood is the most important material for the circular economy

Why wood is the most important material for the circular economy

The Institute for Materials and Wood Technology explains the sustainable uses of wood materials/products and outline their projects that have proven that wood is beneficial to the circular economy.

Wood is a natural material, available in large quantities and is easy to produce, making it the perfect material to consider for the circular economy. The Institute for Materials and Wood Technology (IMWT) at the Bern University of Applied Science are transforming the ways in which we can use wood to benefit the circular economy. With a focus on sustainable use of resources, their research and development has led to minimal wood waste; from making new uses for low quality wood that cannot be sold, all the way through to the production of adhesive from wood extraction.

The circular economy

The key concept of the circular economy is to reduce waste levels and increase the recyclability of products. A lot of CO2 is produced in the housing and construction industry and this is something that must change. However, it is interesting to consider the amount of low quality wood that cannot be sold but can be reused – it can be peeled to produce natural bio-based construction board or boards for furniture. If the quality is very low, the wood can easily be made into chips or fibre, which when glued together can produce high quality materials for building and furniture production.

Bark is a product which is not welcome in the wood processing industry and normally bark will be used for energy production. However, the IMWT are in the process of developing a process to extract valuable chemicals from bark in order to produce glue. This development will mean that companies can produce bio-based building materials or furniture; using their own chip, mixing it with their own glue (produced from a water-based extraction of bark) and then create a final product which is made from recycled and reused waste material.

At the IMWT they use a holistic approach as a basis to their research; from the raw material to the final product. Once they start using wood for furniture or building products, it is integral to the institute that the whole process is optimised. Ensuring the amount of energy that is produced – from the cutting down of trees all the way through to the final application – is kept to a minimal amount remains at the top of the agenda. This includes optimising the drying process, using less energy in the gluing process, perhaps seeing if it is viable to substitute to a natural based glue, and finding out how to disassemble the wood pieces at the end of their life.

Wood’s role in plastic reduction

Within wood biomass you can find all of the raw materials to replace plastic; by-products of the wood industry can create new plastics which can then be recycled or reused at the end of their life, unlike most of the average plastics. Adopting some of the techniques and research around using wood for bio-plastic production can benefit the circular economy and create a huge and positive impact on the environment.

Lignin is one of the wood compounds which can be used to create plastic parts. The compound can be easily processed through extrusion machinery to produce plastics for packaging or building materials. The IMWT is working on a process to develop 3D printing materials that can replace plastic. They have also done work developing the by-products of wood bark extraction to produce a duroplastic bio adhesive, a very hard and resistant adhesive for gluing purposes. With these developments it is possible to replace common adhesives for the production of wood-based panels, whilst also creating a high resistant, high tech composite that can enter the market and find application within the automotive industry and the aviation industry.

The Cocoboard project

The Philippines have struggled in the past few years from many hurricanes and natural disasters, thus ruining a vast majority of buildings within the towns. The last significant hurricane to hit the Philippines was in 2013 and the country is still in the process of rebuilding. The IMWT are working alongside the country on a new project; producing cheap building materials using a resource that the country is in abundance of, coconut.

The Cocoboard project is a perfect example of wood products having the ability to transform the circular economy concept; the idea behind the project is to use coconut husk and natural binding agents to create affordable building materials. Ecological construction panels are created from crop residue from the coconut harvest and tannin based glue. The tannin based adhesive can now be produced in the Philippines itself and can be easily combined with the fibre from the coconut husk.

The Cocoboard project is an example of using waste materials from the food industry to produce local products with very little energy. The IMWT have developed special equipment, designed to be as simple as possible, in a bid to reduce costs from energy production. Essentially, Cocoboard is a local product made with local raw material and the development offers the Philippines a cost-effective solution to their housing situation.

The results of the project have indicated that the research and development the IMWT conducted has created additional jobs for people in the coconut industry, whilst also fostering the acceptance of environmentally friendly building materials – creating blueprints for sustainable production. The project has fulfilled two of the United Nation Development Goals and has offered considerable potential to the local economy.

Projects for the future Tailor made bio refinery for wood biomass

How do we respond to the ever-increasing demand for products from chemical industry? How do we fight against global warming? One of the key answers deals with the use of novel and sustainable bio-based building blocks, outperforming fossil-based materials in terms of functionalities and performances.

These existing innovative products still have much higher production costs that affects the price of downstream products, thus slowing down market uptake for sustainable products.

The IMWT will support companies and investors to develop tailor made bio refinery delivering a wide range of molecules with outstanding properties. Beyond substituting fossil raw material with bio-based ones, these molecules will improve the properties of existing materials when substituting the raw material or fully replacing it:

  • Increase fire resistance for automotive and building applications;
  • Improved properties of coatings; and
  • Biodegradability when being used as adhesive formulation in the field of packaging or agriculture.

When developing this tailor-made process, a strong focus is put on the biomass preparation and energy consumption of the process; the strategy being to use no chemicals and only renewable energy. The socio-economic potential is substantial considering the available biomass in Europe. It will contribute to developing a long-term and sustainable perspective for the bio-based economy.

Bonding of wood without any adhesive

The increasing need of environmentally friendly and emission free bonding processes has motivated the IMWT to develop totally new bonding systems. One of these new technologies is so called welding of wood, a very fast assembling process using the linear vibration technology used to assemble plastic parts in the car industry. Within five seconds, the in-situ melting and activating of the thermoplastic lignin of wood pieces can be achieved, creating a very strong and stable bonding line for interior use. The process can be easily used for producing wood board in the furniture industry. To increase the moisture resistance of the assembling, standard varnishes or coating can be applied. No chemicals are used in the process and therefore untreated board can be recycled easily. A further advantage of this technology is the easy communication between the operator and the welding machine, which render the process fully compatible with the concept of Industry 4.0.

Managing a circular economy and full digitalisation of the processes are key to a modern wood processing industry.

Professor Frederic Pichelin
Institute for Materials and Wood Technology
Bern University of Applied Sciences
+41 32 344 03 42
frederic.pichelin@bfh.ch

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