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Effects of preboiling on the acidity and strength properties of heat-treated wood

Abstract

Heat treatment is an alternative to the chemical treatment in wood preservation, which has been used to some extent in improving timber quality. However, reduction in strength properties has been one of the major limitations in the use of this technique and therefore investigations on the use of various pre-treatment methods are highly essential. Wood samples from Scots pine were immersed in already boiling water (100°C) for 20 min followed by 2 h of heat treatment at 160 and 200°C. The acidity and strength properties were determined by measurement of pH and static bending test, respectively. There were no significant changes in pH due to preboiling in both heat-treated and untreated wood. Similarly, preboiling did not result in any appreciable differences in strength both before heat treatment and during heat treatment at 160°C. However, for 200°C heat treatment preboiling reduced significantly the degree of strength loss as indicated by 19.4% reduction in modulus of rupture in preboiled wood compared to 26.6% reduction in unpreboiled wood. From the results of this study it is evident that preboiling has a buffering effect on wood during heat treatment and the higher the intensity of heat treatment the higher the significance of the buffering effect of pre-boiling.

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Acknowledgment

The authors gratefully acknowledge the financial support from the University of Glasgow, UK for funding the research visit of the principal author.

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Correspondence to L. Awoyemi.

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Awoyemi, L., Jarvis, M.C. & Hapca, A. Effects of preboiling on the acidity and strength properties of heat-treated wood. Wood Sci Technol 43, 97–103 (2009). https://doi.org/10.1007/s00226-008-0231-4

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  • DOI: https://doi.org/10.1007/s00226-008-0231-4

Keywords

  • Heat Treatment
  • Strength Property
  • Wood Sample
  • Natural Weathering
  • Wood Preservation