universityfreiburg iufro division 5 conference 5.04.06 – wood drying improving the dimensional...
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UNIVERSITY FREIBURG
IUFRO Division 5 Conference
5.04.06 – Wood drying
Improving the dimensional stability of different
wood species by thermal modification
Denny OHNESORGE
Corbat Holding SA,Swiss
Wood Treatment Technology,
Denmark
University of Freiburg,Institute of Forest Utilization and
Work Science,Germany
INSTITUTE of FOREST UTILIZATION and WORK SCIENCE 2UNIVERSITY FREIBURG
Authors/Institution
Denny OHNESORGE*,Claudia STOLERU and Gero BECKER
Albert-Ludwig-University FreiburgInstitute of Forest Utilization and Work ScienceWerthmannstr. 6D-79085 Freiburg, Germany
E-mail: [email protected]: http://www.forst.uni-freiburg.de/fobawi
Improving the dimensional stability of different wood species by thermal modification
INSTITUTE of FOREST UTILIZATION and WORK SCIENCE 3UNIVERSITY FREIBURG
Objectives and Method
Improvement of wood properties by thermal modification with the aim to develop products for new usages
Moisture-Heat-Pressure-Treatment between 160 and 220°C with
Treatment in a Vaccum kiln dryer
samples
Boards from 4 different wood species
Poster presented results of: Sorbtion ability and Swelling & shrinking
Several tests on hardness and strength
Climate chamber
INSTITUTE of FOREST UTILIZATION and WORK SCIENCE 4UNIVERSITY FREIBURG
Results
Decrease of oven-dry density Decrease of Sorbtion ability Increase of dimensional stability (ASE-Index)
0
5
10
15
20
25
30
35
0 30 50 65 80 90
Relative Humidity [%]
Eq
uil
ibri
um
mo
istu
re c
on
ten
t [%
]
untreated-ads. 160°C-ads. 180°C-ads.untreated-des. 160°C-des. 180°C-des.
-52 -52
-43-48
-54
-45-48
-58
-44-47
-50
-70
-60
-50
-40
-30
-20
-10
0
Ash Fir Oak Beech
AS
E-I
nd
ex
ove
r th
e c
ross
se
ctio
na
l are
a [
%]
160°C
170°C
180°C
Sorbtion ability dimensional stability (ASE-Index)
INSTITUTE of FOREST UTILIZATION and WORK SCIENCE 5UNIVERSITY FREIBURG
Conclusions
Use of thermal modified, indigenous wood species in (for this wood species) new utilizations by improvement of:
Natural durability Dimensional stability
Terracce floorings Bathroom floorings Solid furniture