Abstract
The total fibre charge of fully bleached softwood (SW) kraft pulps at a comparable final brightness value of 88.0% was examined in this study. The results demonstrated that total pulp fibre charge decreased from an initial 95.9 to a final 32.0-41.2μmol/g as the pulp was bleached to ∼88% brightness via different bleaching sequences. A second alkaline extraction stage (E 2) in the bleaching sequence did not lead to a significant pulp brightness increase but caused a reduction of 10.9-15.0% of the total fibre charge, which was retained when the E2 stage was eliminated. Generally, the total pulp fibre charge of SW kraft pulps bleached via DEDED, D(EPO)DED and OQPZP was 18.0-21.0% higher than those bleached with (D+C)EDED, (D+C)(EO)DED and OD(EPO)DD under the conditions studied. Hydrogen peroxide could be used to increase fibre charge 20.0% by employing it as the last stage following a post-chlorine dioxide bleaching as OD(EPO)DP instead of OD(EPO)DD.
Original language | English |
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Pages (from-to) | 231-237 |
Number of pages | 7 |
Journal | Journal of Pulp and Paper Science |
Volume | 32 |
Issue number | 4 |
State | Published - Oct 2006 |
Externally published | Yes |
Keywords
- Bleached pulps
- Fibers
- Kraft pulps
- Pulp properties
- Softwood pulps