Waste and Biomass Valorization
Fig. 2 Length-weighted fiber length distribution of SR-MDF A (upper row) and SR-MDF B (bottom row) treated at a severity of 2.5 (left column) and 4.0 (right column) in relation to beating duration
(SR-MDF A; log R 0 = 2.5)
(SR-MDF A; log R 0 = 4.0)
10 12 14 16 18
10 12 14 16 18
0 2 4 6 8
0 2 4 6 8
0
1
2
3
0
1
2
3
Fiber Length [ mm]
Fiber Length [ mm]
(SR-MDF B; log R 0 = 4.0)
(SR-MDF B; log R 0 = 2.5)
10 12 14 16 18
10 12 14 16 18
0 2 4 6 8
0 2 4 6 8
0
1
2
3
0
1
2
3
Fiber Length [ mm]
Fiber Length [ mm]
0 minutes additional beating 20 minutes additional beating
40 minutes additional beating 60 minutes additional beating
Fig. 3 Relationship between beating duration and beating degree of a SR-MDF (A) and b SR-MDF (B)
80
80
60
60
40
40
20
20
0
0
0
10 20 30 40 50 60
0
10 20 30 40 50 60
Beating duration [min]
Beating duration [min]
( a
b )
)
(
Log R 0 = 2.5
Log R 0 = 2.8
Log R 0 = 3.1
Log R 0 = 3.4
Log R 0 = 3.7
Log R 0 = 4.0
the severity of the steaming treatment, indicating changes in the structural behavior of the fibers following different treatment severities. This effect is less pronounced in sam- ple SR-MDF B, in which the beating degree of all samples was measured to be around 10 °SR without additional beat- ing, and the beating degree after 60 min of beating ranges from 59 °SR at the lowest severity to 64 °SR at the high- est severity treatment. In accordance with the findings for the fiber length distribution, the treatment severity did not
important parameter for comparison of different pulps. As expected, for all samples the beating degree increased with the beating duration. The beating degree of SR-MDF A treated at the lowest severity increased from 9 °SR without beating to 41.5 °SR after 60 min of beating, while the beat- ing degree of the same sample treated at the highest severity increased from 17 °SR without additional beating to 71 °SR after 60 min of beating. Therefore, the beating degree resulting from the same beating duration increased with
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