Predicting CTMP bleachability using wood shavings
2011 (English)In: 16th International Symposium on Wood, Fiber and Pulping Chemistry - Proceedings, ISWFPC, 2011, Vol. 1, 613-616 p.Conference paper (Refereed)
To predict the brightness reduction in a chemithermomechanical process as well as the bleachability of pulps produced from different species of wood raw materials there are, at present, no shortcuts available. Pulps have to be manufactured in pilot or mill scale and bleached; evaluating and predicting the bleachability has consequently been very resource consuming and thus expensive - until now! Due to this, we have used a laboratory method based on 60 Ã— 60 mm wood shavings making it possible to predict the bleachability of primarily chemithermomechanical pulps but also other mechanical pulps. Our experiments showed that retention time and impregnation temperature appears to have no impact on the final brightness of birch shavings. When being subjected to a simulated chemithermomechanical pulp process, eucalyptus exhibited an increase in chromophore content before the bleaching stage. In addition, eucalyptus suffered from severe alkaline darkening. After the bleaching stage, the alkaline darkening diminished. A higher retention temperature resulted in lower brightness of the eucalyptus shavings compared to when using a lower retention temperature. Birch reached the highest final brightness levels and had a higher overall yield too.
Place, publisher, year, edition, pages
2011. Vol. 1, 613-616 p.
IdentifiersURN: urn:nbn:se:miun:diva-16752ScopusID: 2-s2.0-84855713005OAI: oai:DiVA.org:miun-16752DiVA: diva2:545180
16th International Symposium on Wood, Fiber and Pulping Chemistry, ISWFPC;Tianjin;8 June 2011through10 June 2011;Code88003