INDUSTRY
Algae and vegetable oils give
wood a whole new shine
19 July 2016
KEY THEME: OPEN INNOVATION
by Benedict O’Donnell
Natural oil and nanoparticles are making wood varnish an environmentally friendly product. Credit: Pixabay
Biological alternatives to oil-based varnish are turning wood into one of the most sustainable
building materials available.
Unlike PVC or aluminium, its feedstock is renewable, its production is carbon neutral and its waste is
biodegradable, yet wood has one major drawback – it starts to degrade when exposed to moisture,
harsh temperatures and bright lights.
Usually, the solution is to coat it in oil-based paints and varnishes – that’s good for the finish, but not
so great for the environment.
One solution fresh out of the lab is a formula containing vegetable oil, a water-based solvent, and a
pinch of inorganic nanoparticles.
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‘The nanoparticles help reinforce the structural integrity of the coating and catalyse molecular bonds
within it,’ said Carlos del Castillo, from Inspiralia in Madrid, Spain, who coordinated the EU-funded
project ECOVARN that developed the mixture.
‘The result is a natural coating that is both reliable
and looks good. That was not around before.’
Because coating formulations are extremely
complex, swapping ingredients in them is tricky.
Successful recipes owe at least as much to
experimentation as they do to well-planned
chemistry.
Seaweed
The efforts of the research teams at ECOVARN
have been pushed further in the NEXT1KOAT
project, which was coordinated by Francisco Melero
from the Technical Research Centre of Furniture
and Wood (CETEM) in Murcia, Spain.
‘Extreme cold in
Sweden has
damaged some of
our testing
equipment, but the
window frames are
all fine.’
Dr Aleš Ugovšek, Project
Manager, M SORA
‘We extract the raw materials from seaweed grown off the coast of Ireland and Scotland,’ he said. ‘A
series of chemical steps then transforms the biomass into natural alcohols that we can process into
sustainable paints and varnishes.’
In addition to benefits for the climate, these coatings present fewer health hazards to woodworkers and
consumers. Furniture-makers using conventional wood coatings are obliged to work in well-ventilated
areas and wear protective masks because the products are dissolved in toxic toluene. By contrast,
many of the bio-based alternatives are water-borne.
As well as being safer, some of these new coatings and treatments can enhance the properties of
wood, such as its ability to insulate.
M SORA, a window frame manufacturer in Žiri, Slovenia, has been working over the past years with the
University of Ljubljana to develop better insulating window frames made of thermally modified wood.
Their product traps as much as twice the heat that earlier window frames can contain and even
outperforms many plastic and aluminium frames sold today.
With support from the EU-funded WINTHERWAX project, M SORA and its partners are now attempting
to coat this thermally treated timber in a naturally derived wax to increase its lifespan.
According to Dr Aleš Ugovšek, the project manager at M SORA who coordinated WINTHERWAX, dipcoating the timber and heating it helps cram the wax inside its cellular structure. The resulting surface
is highly hydrophobic and unappetising to insects and fungi.
‘We are testing how well the wax extends the lifespan of our thermally treated wood in five test sites
across Europe,’ said Dr Ugovšek. ‘So far, extreme cold in Sweden has damaged some of our testing
equipment, but the window frames are all fine.’
More info
ECOVARN
NEXT1KOAT
WINTHERWAX
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