'Wood foam' could provide an insulation hit

CleanTechnica

An effective new form of insulation created entirely from wood has been created by researchers at the Fraunhofer Institute for Wood Research, WKI in Braunschweig, Germany.

The new insulation – which is essentially foamed wood – could serve as a petrochemical-free, environmentally friendly alternative to the toxic insulations currently in widespread-use, according to the researchers.

“Our wood foam can be used in exactly the same way as conventional plastic spray foams, but is an entirely natural product made from sustainable raw materials,” says Professor Volker Thole of the WKI.

This new wood foam can produced via a rather simple process. All that you have to do is grind wood up into a very fine consistency (till the tiny wood particles become a slimy mass), and then add gas to expand it into a frothy foam that is then force-hardened. This hardening process is aided by many of the naturally occurring substances in the wood itself. Alternately, there are other methods that can be used to create the final product.

“It’s a bit like baking, when the dough rises and becomes firm in the oven,” Professor Thole explains. “This wood foam is a lightweight base material that can then be made into rigid foam boards and flexible foam mats.”

While wood-based insulation materials have been around for some time, the products currently in use have significant drawbacks. As examples, mats of wood fibres, and also wood wool, both tend to shed fibres “as they fibrillate and are less stable in shape than insulation materials made of plastic.”

“Over time, the currently used insulation mats made of wood fibres tend to sink in the middle due to temperature fluctuations and damp. This, to some extent, adversely affects its insulating properties,” explains Professor Thole. “The wood foam developed at the WKI, however, is every bit as good as conventional plastic foams in this regard.”

“We analysed our foam products in accordance with the applicable standards for insulation materials. Results were very promising; our products scored highly in terms of their thermo-insulating and mechanical properties as well as their hygric, or moisture-related, characteristics,” Professor Thole continues.

The researchers are currently continuing their work by experimenting with different types of wood – aiming to determine which tree species work the best. They are also working to develop suitable processes for mass-producing wood foams on an industrial scale. The researchers note that the material also could potentially be used as packaging – potentially replacing the petrochemical-based material expanded polystyrene.

Source: Fraunhofer WKI

Originally published by CleanTechnica. Reproduced with permission.