The structural model of a mineral with dispersed  modified zeolite. When used to make composite  wood panels, Fraunhofer researchers say it absorbs formaldehyde, reducing emissions by as much as 40%.

BRAUNSCHWEIG, GERMANY -- Researchers at the Fraunhofer Institute for Wood Research, Wilhelm-Klauditz-Institut (WKI) in Braunschweig and the Fraunhofer Institute for Silicate Research (ISC) in Würzburgin, said they have discovered a new method to reduce emissions by up to 40 percent from particleboard by using modified zeolites to absorb formaldehyde.

The researchers said these zeolites are aluminosilicates that function as a molecular sieve due to their extremely large inner surface and porous structure and thus can devour formaldehyde emissions particularly well.

Dr. Katrin Bokelmann, project manager of the Fraunhofer Institute for Silicate Research, said, “Zeolites are already used as a filling material in particleboards, but it’s an entirely new idea to use them for absorbing pollutants in wood materials.”

If the Fraunhofer Institute's concept proves commercially viable, including in high-volume production mills, it would have huge implications for manufacturers and users of composite wood products, including particleboard, MDF and plywood.

Since the 1950s, formaldehyde, especially urea formaldehyde, has been the main ingredient used in resins and glues for the manufacture of particleboard, MDF and plywood panels. Over the decades, resin manufacturers and composite wood panel producers have made long strides to reduce formaldehyde emissions. Yet, formaldehyde remains under the regulatory microscope because the International Agency for Research on Cancer (IARC) of the World Health Organization (WHO) has classified formaldehyde as a human carcinogenic.

IARC's designation has helped fuel regulatory activity by the California Air Resources Board and the U.S. Environmental Protection Agency.

Fake Is Better Than Real
The researchers said they were not able to achieve sufficiently high rates of absorption in their tests of various commercially available or natural minerals. 

Dr. Jan Gunschera, project manager of the WKI, said, “We noticed a 70 percent boost in the adsorption rate after we added formaldehyde to the processed material in our measuring chambers and then we put 5 percent by weight of the zeolite powder directly into our sample particleboards made of spruce roundwood. The result was that formaldehyde emissions from the board dropped 40 percent – both short-term and long-term tests of one month confirm these findings. In other words, the air in living spaces should be measurably improved. Our tests indicate that this technology can even reduce indoor air pollutant levels.”

The researchers added that the properties of the composite wood materials tested did not show any negative influence from the artificial zeolites.

A patent has been applied for the new technique. The researchers said they think that modified zeolites, used with furniture, ceiling panels or other wood products– could conceivably reduce not only formaldehyde but also other aldehyde levels in indoor air.

The WKI is seeking partners from the wood materials industry to mass-produce composite wood products. A sample panel will be on display at the Bau Fair in Munich, Germany, January 17 to 22. 

Read Fraunhofer Institute's modified zeolite press release.

Also read: CARB issues two formaldehyde rule info updates