Influence of birch xylan adsorption during kraft cooking on softwood pulp strength
2005 (English)In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, Vol. 20, no 4, 436-441 p.Article in journal (Refereed) Published
The dissolution, degradation and redeposition of xylan in the kraft cooking of birch pulp were investigated. The molecular weight of the dissolved xylan was determined through gel permeation chromatography, and the loss in molecular weight could be correlated with the amount of degraded xylan in the initial stages of the kraft cook. This indicates that peeling is the only significant xylan degradation reaction taking place early in the cook. Two different birch black liquors containing xylan with molecular weights of 12.20 g/mol and 5.95 g/mol, respectively, were added to softwood kraft cooks in order to determine the effect of birch xylan on pulp strength properties. The results show an increase in both tensile strength and tensile stiffness. The magnitude of the strength increase was greatly affected by the molecular weight of the xylan added. Adding high-molecular-weight xylan increased the tensile strength by more than 10%, as measured at a beating degree of 1000 PFI revolutions. Tensile stiffness was also increased by xylan addition, though more so when the xylan was of high rather than low molecular weight.
Place, publisher, year, edition, pages
2005. Vol. 20, no 4, 436-441 p.
kraft pulping; hydroxyl ion concentration; xylan; hemicellulose; dissolution; degradation; precipitation; molecular weight; surface properties; paper strength; adsorption
Paper, Pulp and Fiber Technology
IdentifiersURN: urn:nbn:se:kth:diva-7712DOI: 10.3183/NPPRJ-2005-20-04-p436-441ISI: 000235258200010ScopusID: 2-s2.0-30344439844OAI: oai:DiVA.org:kth-7712DiVA: diva2:12818
QC 201007022007-11-232007-11-232010-07-02Bibliographically approved