wood research centre roger e. hernÁndez iufro division 5 conference 5.04.06 wood drying
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Wood Research Centre2
Department of Wood and Forest Sciences, Laval University, Quebec (Qc), Canada G1K 7P4
Effect of temperature on changes in physical properties of wood below and above the fiber saturation point
Roger HERNÁNDEZ*
and Zaira SILVA
Slovakia
European Union
Quebec
Wood Research Centre
Aim of work and methods
3
To study the effect of the equilibrium moisture content (EMC) on wood properties below and above the fiber saturation point (FSP) for two hardwoods at two temperatures
Desorption experiments using two experimental techniques Evaluation of EMC, shrinkage, FSP, and compression stiffness
in tangential direction
Wood Research Centre
Results
4
EMC-WP relationship of yellow EMC-WP relationship of yellow birch and beech at 25°Cbirch and beech at 25°C.
Shrinkage-EMC relationship of Shrinkage-EMC relationship of yellow birch at 25°Cyellow birch at 25°C
0
20
40
60
80
100
120
Water potential (J / kg-1)EM
C (
%)
Yellow birch
Beech
-106 -105 -104 -103 -102 -101 -100
Relative humidity (%)
0.07 48.36 92.99 99.28 99.93 99.99 100
0
2
4
6
8
10
0 20 40 60 80 100 120EMC (%)
Woo
d sh
rink
age
(%)
VolumetricTangentialRadialPSF
Yellow birch at 25°C
Wood Research Centre
At equilibrium, wood shrinkage begins well At equilibrium, wood shrinkage begins well above the fiber saturation pointabove the fiber saturation point.
The EMC affects Young’s modulus in The EMC affects Young’s modulus in tangential direction well above the FSPtangential direction well above the FSP;
A region hence exists where the loss of A region hence exists where the loss of bound water takes place in the presence of bound water takes place in the presence of liquid waterliquid water.
Conclusions
.