Why wood can replace other materials
The forest sector likes to talk about the importance of substitution, in which one material replaces another. It should be possible to use wood as a raw material to replace fossil-based materials to a greater extent. But is it possible to use wood for just about anything?
Åsa Ek is Vice President Biofoams at Stora Enso, which develops and produces solutions based on wood and biomass for a range of industries and applications worldwide. Ek works in the Biomaterials Innovation business area, which conducts research and development into the products of tomorrow. She envisages many different uses for versatile wood. The reason is quite simple:
“Everything that’s made from oil can be made from wood,” she says.
Wood can mainly be used in three different areas.
“We can benefit from wood’s existing structures and properties and replace steel and concrete in buildings. We can use the various substances in wood, such as pine oil and lignin, to replace fossil-based alternatives. Furthermore, it’s possible to break down wood on a molecular level. The first plastic was actually made from cellulose from wood, and not from oil as you might expect,” says Ek.
But making today’s widely used plastics from wood is difficult and uneconomical.
“First, the raw material must be broken down into small molecules and then assembled into plastic. It’s good that we don’t have to add new carbon to the cycle, but it’s expensive and time-consuming compared to using oil. Even if plastic is made from wood raw materials, it is just as difficult for nature to break down as fossil-based plastic,” Ek says.
The protective barrier
Research into wood-based plastics therefore focuses on molecules that can be more easily obtained from wood raw materials, and which in turn can make plastics with better properties. In some packaging, for example fruit juice cartons, a layer of film is needed between the cardboard and its contents. The film retains taste and prevents moisture, fat, and oxygen affecting the quality of the juice. Research is now underway to reduce the use of fossil plastics, or even to completely replace the plastic barrier with a fossil-free variant based on wood raw materials. But what are the challenges to replacing fossil-based raw materials with wood-based ones?
“Consumers have to learn to distinguish between different materials, what should be sorted as plastic and what should be sorted as paper. Mixing paper products with plastic recycling creates problems. Another challenge is getting the industry to adjust. It is rare that a product has exactly the same properties as the one it replaces. We must therefore help decision-makers grasp all the advantages of new products,” explains Ek, who sees a need for greater collaboration between researchers and industry and for the two to learn from each other.
“Many established standards and processes need to be changed, and new measurement methods may need to be developed. This is about thinking what materials are used for, what problems need to be solved and harnessing the advantages of wood-based products.”
Source: Swedish Forest Industries
