Details

Autor(en) / Beteiligte

• GARCIA ESTEBAN, Luis
• GRIL, Joseph
• DE PALACIOS DE PALACIOS, Paloma
• GUINDEO CASASUS, Antonio

Titel

Reduction of wood hygroscopicity and associated dimensional response by repeated humidity cycles

Ist Teil von

• Annals of forest science., 2005-04, Vol.62 (3), p.275-284

Ort / Verlag

Les Ulis: EDP Sciences

Erscheinungsjahr

2005

Link zum Volltext

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• The reduction of wood response to variations of ambient humidity, described as kind of ageing, has been studied from both points of view of moisture uptake and dimensional changes. Clearwood specimens from 3 gymnosperms (Pinus sylvestris L., Pinus pinaster Ait., Pinus insignis Dougl.) and 4 angiosperms (Populus spp., Quercus pyrenaica Willd., Entandrophragma cylindricum Sprague, Chlorophora excelsa Benth. & Hook f.) were subjected to five wet-dry cycles and their moisture content and dimensional changes in radial and tangential direction at three increasing levels of relative humidity (57.6, 84.2 and 90.2%) were measured before and after the treatment. For a given increase of relative humidity, a coefficient of hygroscopic ageing was defined as the relative decrease of moisture uptake, and the coefficient of dimensional ageing as the difference of swelling strain before and after ageing. All species exhibited a clear ageing effect, much stronger in the wet range than in the dry range. Calculation of swelling coefficients suggested that in some cases the relation between swelling strain and moisture content is no longer linear in aged wood.