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EVALUATION AND COMPARISON OF QUALITY EVALUATION AND COMPARISON OF - - PowerPoint PPT Presentation
EVALUATION AND COMPARISON OF QUALITY EVALUATION AND COMPARISON OF - - PowerPoint PPT Presentation
EVALUATION AND COMPARISON OF QUALITY EVALUATION AND COMPARISON OF QUALITY OF BEECH WOOD (FAGUS SILVATICA L.) AFTER VACUUM DRYING AND HF-DRYING VACUUM DRYING AND HF DRYING. Daniel Karpinsk Prong test - Casehardening ENV 14464 - Casehardening
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ENV 14464 - Casehardening
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GOST 11603-73 - Internal stress
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Drying time
Vacuum drying I (with equalizing)
=> 92 h
Vacuum drying II (without equalizing)
=> 72 h
HF drying (after 160 h pre-drying)
=> 10,5 h
100,0% 60,0% 70,0% 80,0% 90,0% M C (% ) 20 0% 30,0% 40,0% 50,0% A v e ra n g e M 0,0% 10,0% 20,0% 0,0 10,0 20,0 30,0 40,0 50,0 60,0 70,0 80,0 90,0 100,0 Drying time (h) y g ( )
vacuum I vacuum II HF drying
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Results
Final MC
Vacuum drying I
=> 2,9 – 3,2 % V d i II 3 7 4 8 %
Final MC
Vacuum drying II
=> 3,7 – 4,8 %
HF drying
=> 6,1 – 7,5 %
7% 8%
%)
2% 3% 4% 5% 6%
isture content (%
0% 1% 2%
1 2 1 2 1 2 3 4 Vacuum drying I Vacuum drying II HF drying Moi acuu d y g acuu d y g d y g Drying / Sample
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Results
MC gradient MC gradient
Vacuum drying I
=>
gradient max.
0,2 %
Vacuum drying II
=> 1 to 1 7 %
Vacuum drying II
=> 1 to 1,7 %
HF drying
=>
- 0,6 to -1,2 %
Moisture content gradient
7% 8% 4% 5% 6% 7% e content (%)
Vacuum drying I Vacuum drying II HF drying
0% 1% 2% 3% Moisture
y g
0% Surface I Middle Surface II Drying / Sample
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Results
Casehardening prong test Casehardening – prong test
Vacuum drying I
=> 2,2 – 5,4 %
Vacuum drying II
=> 6 6 7 %
Vacuum drying II
=> 6,6 – 7 %
HF drying
=> 6,8 – 11,5 %
10% 12% 4% 6% 8% ehardening (%) 0% 2% 4% 1 2 1 2 1 2 3 4 Case Vacuum drying I Vacuum drying II HF drying Drying / Sample
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Results
Casehardening ENV 14464 Casehardening – ENV 14464
Vacuum drying I
=> 0,5 – 1,2 mm
Vacuum drying II
=> 1 46 1 52 mm
Vacuum drying II
=> 1,46 – 1,52 mm
HF drying
=> 0 – - 2,8 mm
0 5 1 1,5 2
- 1
- 0,5
0,5 1 2 1 2 1 2 3 4 Vacuum drying I Vacuum drying II HF drying hardening (mm)
- 2,5
- 2
- 1,5
- 1
Caseh
- 3
, Drying / Sample
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Results
Internal stress (B N Ugolev method) Internal stress (B. N. Ugolev method)
- 4,0
- 3,0
- 2,0
- 1,0
0 0 Surface I Middle I Middle II Middle III Middle IV Surface II (MPa) 0,0 1,0 2,0 3,0 4,0 Internal stress
Prong test Casehardening - ENV 14464 Prong test
8%
Casehardening - ENV 14464
1 5
5,0 6,0
Vacuum drying I 1 Vacuum drying I 2 Vacuum drying II 1 Vacuum drying II 2
4% 5% 6% 7% 8%
1 1,5
4% 5% 6% 7% 8%
1 1,5
0% 1% 2% 3% 4%
0,5
0% 1% 2% 3% %
0,5
1 2 Vacuum drying I
1 2 Vacuum drying I
1 2 Vacuum drying II
1 2 Vacuum drying II
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Conclusion
li l i d d h h d f i
quality results is depend on the method for measuring
Prong test
- nly reflects the stress condition in the surface layer
high stress gradients leads to strong deformation of the prong => indicating
a low drying quality
slicing tests (as described in ENV 14464)
g ( )
is based on the internal stress difference between surface and core layers more reflects an average stress level => indicating a better drying quality
the vacuum and the HF drying methods and the resulting drying the vacuum and the HF drying methods and the resulting drying
quality of dried material
- the material dried in vacuum has lower moisture content gradient and
ll d f h d i smaller degree of casehardening
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