| Autor: |
Maria Cristina Area, Fernando E. Felissia, M. Graca V. S. Carvalho, Paulo J. Ferreira, Olga M. Barboza, Dora I Benoechea |
| Jazyk: |
angličtina |
| Rok vydání: |
2011 |
| Předmět: |
|
| Zdroj: |
BioResources, Vol 6, Iss 2, Pp 2077-2090 (2011) |
| Druh dokumentu: |
article |
| ISSN: |
1930-2126 |
| Popis: |
The addition of a phosphonated chelant (DTPMPA) at different points of a TCF bleaching sequence and its effect on pulp properties were studied in this work. An industrial Eucalyptus grandis kraft pulp was submitted to a counter-ion exchange (Ca2+ or Na+ form) and was then bleached using DTPMPA in the washing or in the bleaching stages of two distinct sequences: OOpP and OQOpP (20 pulps). The counter-ion exchange affected fibre length, as well as the handsheets bulk and air permeability (higher for Na+-based pulps) and handsheet tensile strength, brightness, skeletal density, and total porosity based on Hg porosimetry (higher for Ca2+-based pulps). The hydrogen peroxide consumption in Op and P stages achieved the lowest values when the chelant was distributed rather than applied in a separate Q stage. The addition of chelant in the P stage provides pulps with higher ISO brightness (>85%). The chelant effects were always more noticeable in Ca2+-based pulps. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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