In the wood industry, tree bark is considered a waste product that is usually either burned to generate energy or laid out as mulch in beds. The bark can also be used to produce numerous sustainable products such as furniture panels or even shoe soles and handbags. An industrial designer has now experimentally teased out the actual potential of tree bark.
The bark of a tree makes up ten to 20 percent of its total volume. Extrapolated from the wood felled in this country, around four million cubic meters of bark are produced every year. But this enormous amount is little more than waste for the modern wood industry. 44 percent of the peeled tree bark is simply burned to generate energy and heat or ends up as mulch in the garden center. Only around 19 percent of wood waste is given a second life as an additive for chipboard.
A comeback for the bark
“The reason why such biomaterials hardly play a role in the construction industry and design is that there is little knowledge about their structure and the resulting properties and therefore not about their processing and applications,” says industrial designer and researcher Charlett Wenig . But that was not always so. For example, the indigenous peoples of North America and the Amazon once built their canoes out of bark. And as late as the 19th century, lumberjacks’ huts in some parts of Austria were made of bark.
In order to enable tree bark to make a comeback as a useful material, Wenig has now carried out extensive research into its properties and possible areas of application. Their test subjects included the bark of the Brandenburg Scots pine, the English oak, the European larch and the European white birch.
From the table top to the sole of the shoe
In her tests, the researcher found, for example, that bark can be pressed together with little energy expenditure – without any chemical glues, but only using the natural adhesive properties of the bark. “The pressing process resulted in panels that could be used in furniture construction as shelves and table tops, as they can be sawn, milled and drilled. “They also have a surface quality that is comparable to the sanded surfaces of solid wood,” explains Wenig.
In further experiments, the industrial designer discovered even more unconventional uses for the peeled bark. When Wenig treated the bark of the Brandenburg pine with a glycerin-water solution, it became so flexible that it was suitable as an elastic sole for high heels, sandals and ankle-high shoes. Wenig even managed to weave the flexible bark into jackets and skirts.
“Based on my research results, I see the potential of bark not in the production of clothing, but rather for accessories such as bags, shoes and jewelry or in the area of interior design, as a packaging material and temporary, light architecture,” says the researcher. So it could well be that new creations made from bark will soon be waiting for us in furniture stores and shoe stores.
Source: Technical University of Berlin