Birch (Betula pendula) Wood Discolouration during Drying. Effect of Environmental Factors and Wood Location in the Trunk
- 27 June 2002
- journal article
- Published by Walter de Gruyter GmbH in Holzforschung
- Vol. 56 (4), 348-354
- https://doi.org/10.1515/hf.2002.055
Abstract
Summary: Birch wood discolours during artificial drying, which is a considerable problem for the use of birch as raw material in the mechanical wood industry. In this investigation sample boards of Betula pendula were sawn to the dimensions used as raw material for parquet billets. The variables studied were those that may affect wood discolouration: growing site, felling date, length of the storage period for logs and location of the wood in the trunk. Discoloration of birch wood was studied in conventional and vacuum drying processes. The wood layer of about 2–5 mm under the yellow surface of conventionally dried boards remained light-coloured, while the inner wood of the boards became discoloured. During vacuum drying, however, the inner wood of sample boards clearly became discoloured. The radial location of the wood in the trunk affected the colour of dried wood more than the longitudinal location did. To keep the colour of dry wood as light as possible, it may be best to fell birch in winter and store the wood for several weeks before conventional drying. On the other hand, the lightest coloured wood obtained during vacuum drying was from autumnfelled five weeks stored birches, which may indicate differences in the process of discoloration in these two drying methods.Keywords
This publication has 5 references indexed in Scilit:
- Birch as sawn timber and in mechanical further processing in Finland. A literature studySilva Fennica Monographs, 2000
- Untersuchung über einige Faktoren, welche die Bildung von braunen Trocknungsverfärungen inPinus radiata begünstigenEuropean Journal of Wood and Wood Products, 1997
- Prevention of brown discoloration in European oakwood occurring during kiln drying by a vacuum process: Colorimetric comparative study with a traditional processEuropean Journal of Wood and Wood Products, 1992
- La qualité de l'aspect des placages de chênes : mesures de couleur et critères d'appréciation des professionnels français et italiensAnnals of Forest Science, 1990
- Mesure de la variabilité de la couleur du bois. Nouvelle méthode appliquée aux carottes de sondage.Annals of Forest Science, 1987