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Licensed Unlicensed Requires Authentication Published by De Gruyter June 29, 2019

Treatment of European beech with a new wood fire retardant agent based on in situ deposition of calcium oxalate

  • Tom Franke and Thomas Volkmer EMAIL logo
From the journal Holzforschung


European beech (Fagus sylvatica L.) was impregnated in a two-step process with aqueous solutions of potassium oxalate and calcium chloride successively. These compounds are intended to react in situ to the water-insoluble salt calcium oxalate and the reaction by-product potassium chloride. In order to assess the treatability, the solid uptake after the first impregnation and after the treatment was examined. The fixation of the precipitated salts was measured in leaching tests according to the European standard EN 84. The reaction to fire of mineralized beech was tested following the standard ISO 11925-2. A weight percentage gain of appr. 35% indicates a sucessful treatment of the beech with the mineralization agents. The weight percentage gain after leaching indicates a sufficient fixation of calcium oxalate in the wood. Furthermore, results from flammability tests indicate improved fire resistance due to the mineralization.

  1. Author contributions: All the authors have accepted responsibility for the entire content of this submitted manuscript and approved submission.

  2. Research funding: The authors gratefully acknowledge the Swiss Innovation Agency (Innosuisse) for the financial support.

  3. Employment or leadership: None declared.

  4. Honorarium: None declared.


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Received: 2019-02-18
Accepted: 2019-05-28
Published Online: 2019-06-29
Published in Print: 2019-10-25

© 2019 Walter de Gruyter GmbH, Berlin/Boston

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