Water sorption in wood and modified wood at high values of relative humidity: Part 2: Appendix. Theoretical assessment of the amount of capillary water in wood microvoids

TY - JOUR

T1 - Water sorption in wood and modified wood at high values of relative humidity

T2 - Part 2: Appendix. Theoretical assessment of the amount of capillary water in wood microvoids

AU - Engelund, Emil Tang

AU - Thygesen, Lisbeth Garbrecht

AU - Hoffmeyer, Preben

PY - 2010/4/1

Y1 - 2010/4/1

N2 - A theoretical study of the amount of moisture held in wood as capillary condensed water in the relative humidity (RH) range of 90-99.9% is carried out. The study is based on idealized geometries of the softwood structure related to micrographs. It is confined to structural elements such as bordered pits and the pointed ends of tracheids. The theoretical amount of water in these elements is found by employing the Kelvin equation. An equal amount of earlywood and latewood cells with different geometries and with different amounts of pits is assumed. The effect of pit aspiration is considered, and different degrees of pit aspiration are assigned to earlywood and latewood. We suggest based on the results that capillary condensation makes only a very small contribution to the equilibrium moisture content. At 99.9% RH the contribution amounts to less than 0.0035 kg water per kg dry wood. This is in line with the experimental results presented in Part 1 of this study.

AB - A theoretical study of the amount of moisture held in wood as capillary condensed water in the relative humidity (RH) range of 90-99.9% is carried out. The study is based on idealized geometries of the softwood structure related to micrographs. It is confined to structural elements such as bordered pits and the pointed ends of tracheids. The theoretical amount of water in these elements is found by employing the Kelvin equation. An equal amount of earlywood and latewood cells with different geometries and with different amounts of pits is assumed. The effect of pit aspiration is considered, and different degrees of pit aspiration are assigned to earlywood and latewood. We suggest based on the results that capillary condensation makes only a very small contribution to the equilibrium moisture content. At 99.9% RH the contribution amounts to less than 0.0035 kg water per kg dry wood. This is in line with the experimental results presented in Part 1 of this study.

U2 - 10.1515/hf.2010.061

DO - 10.1515/hf.2010.061

M3 - Journal article

SN - 0018-3830

VL - 64

SP - 325

EP - 330

JO - Holzforschung

JF - Holzforschung

IS - 3

ER -