Transcript Folie 1

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
University of Freiburg,
Institute of Forest Utilization and
Work Science,
Germany
Wood Treatment
Technology,
Denmark
UNIVERSITY
FREIBURG
Authors/Institution
Denny OHNESORGE*,
Claudia STOLERU and Gero BECKER
Improving the dimensional stability
of different wood species by
thermal modification
Albert-Ludwig-University Freiburg
Institute of Forest Utilization and Work Science
Werthmannstr. 6
D-79085 Freiburg, Germany
E-mail: [email protected]
Web: http://www.forst.uni-freiburg.de/fobawi
INSTITUTE of FOREST UTILIZATION and WORK SCIENCE
UNIVERSITY
FREIBURG
1
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
Several tests
on hardness
and strength
Treatment in a
Vaccum kiln dryer
samples
Boards from 4 different
wood species
Poster presented results of:
Sorbtion ability and
Swelling & shrinking
Climate chamber
INSTITUTE of FOREST UTILIZATION and WORK SCIENCE
UNIVERSITY
FREIBURG
2
Results
Equilibrium moisture content [%]
untreated-ads.
untreated-des.
160°C-ads.
160°C-des.
180°C-ads.
180°C-des.
35
30
25
20
15
10
5
0
0
30
50
65
Relative Humidity [%]
80
90
Sorbtion ability
INSTITUTE of FOREST UTILIZATION and WORK SCIENCE
ASE-Index over the cross sectional area [%]
 Decrease of oven-dry density
 Decrease of Sorbtion ability
 Increase of dimensional stability (ASE-Index)
Ash
Fir
Oak
Beech
0
-10
-20
160°C
170°C
-30
180°C
-40
-45-44
-50
-60
-52-54
-58
-52
-43
-47
-48-48
-50
-70
dimensional stability (ASE-Index)
UNIVERSITY
FREIBURG
3
Conclusions
 Use of thermal modified, indigenous wood species in (for
this wood species) new utilizations by improvement of:
Natural durability
Terracce floorings
Dimensional stability
Bathroom floorings
INSTITUTE of FOREST UTILIZATION and WORK SCIENCE
Solid furniture
UNIVERSITY
FREIBURG
4