European researches claim they are fast approaching the successful production of new wood fibre-based insulation materials which include a cellulose foam spray.

German-based Fraunhofer Institute for Wood Research, Wilhelm-Klauditz-Institut (WKI), announced in March that they had developed a method for creating foam from wood particles.

They say that the product will be a cleaner, greener alternative to petrochemical plastics that are currently used for spray insulation applications, and that they have addressed some of the shortfalls of other wood fibre insulation materials on the market.

“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,” explains Professor Volker Thole of the WKI.

“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 extend adversely affects its insulating properties.”

“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,”

The VTT Technical Research Centre of Finland also claims to have produced sprayable cellulosic insulation foam but say they will go further by working to produce other wood-fibre insulation products in a bid to replace plastic and mineral wool insulation entirely.

“The new materials will enable mass production of high-quality insulation products, which will replace products made of non-renewable or poorly recyclable raw materials,” reads the VTT website.

“The project aims to raise the overall performance of wood-based insulation to the same level as that of polyurethane insulation. The insulation properties of cellulosic materials can be improved by using foam-like structures to create closed-like air pockets in the material.”


The WKI explain that their product is made by grinding wood very finely until the tiny wood particles become a slimy mass. Gas is then added to expand the cellulose into a frothy foam that is then hardened.

They clarify that the hardening process is aided by natural substances contained in the wood itself although their press release doesn’t specifically mention if other hardening agents are used conjunctively—just that they are petrochemical-free.

In an alternative method developed by WKI, specific chemical processes are used to produce the final product which is baked in the oven and can form rigid foam boards and flexible foam mats.


Both the WKI and VTT express that their research and development will result in a wood fibre based insulation product that is a greener alternative to oil-based plastic insulation. The WKI also expressed that their wood foam is every bit as good as conventional plastic foams in terms of its insulation performance.

The VTT says sprayable cellulose insulation will also mean that less safety equipment is needed for insulation installation:

“Because the raw materials of plastic-based in-situ spray-on polyisocyanurates and polyurethanes (PIR and PUR) contain hazardous components, insulation workers must wear protective respirator masks and protect their skin during installation work.”

“In contrast, the spray-on cellulosic foam to be developed by the WoTIM project will involve no health hazards, either during or after its installation.”

The WKI says they are currently experimenting with different types of wood to discover which tree species make the best basis for their product

They also hope to create a suitable mass-producing process for wood foams on an industrial scale which they suggest could mean the replacement of expanded polystyrene in packaging.