Abstract
The effectiveness of various bleaching chemicals on softwood kraft pulp
fibres of different cell-wall thickness was studied and the effect of
primary fines on bleaching was investigated. Softwood kraft pulps of
different average cell-wall thickness were obtained by fractionating
with hydrocyclones. After the fractionation unbleached softwood kraft
pulp fractions were treated with oxygen, chlorine dioxide, hydrogen
peroxide and ozone. In the oxygen stage, kappa reduction increased and
the consumption of sodium hydroxide per unit decrease in kappa number
decreased with cell wall thickness at a given primary fines content. The
consumption of hydrogen peroxide per unit decrease in kappa number
increased with cell wall thickness at the same primary fines content.
The consumption of chlorine dioxide and ozone per brightness unit gained
decreased with cell wall thickness. In addition, the results showed
that primary fines adversely affected the hydrogen peroxide bleaching of
the pulp.
| Original language | English |
|---|---|
| Pages (from-to) | 362-367 |
| Number of pages | 6 |
| Journal | Appita Journal |
| Volume | 64 |
| Issue number | 4 |
| Publication status | Published - 2011 |
| MoE publication type | A1 Journal article-refereed |
Keywords
- bleaching
- oxygen
- ozone
- hydrogen peroxide
- chlorine dioxide
- fines
- cell wall thickness