journal article·2018-09-25

Dewatering properties of low grammage handsheets of softwood kraft pulps modified to minimize the need for refining

Hafizur Rahman, Per Engstrand, Peter Sandström, Björn Sjöstrand

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Abstract

Abstract Previous paper (Rahman et al. 2017) showed that the yield of softwood kraft pulp increased by the addition of either polysulfide or sodium borohydride because of higher hemicellulose retention. An increase in hemicellulose content can make dewatering more difficult as WRV of the pulp increases, but instead, an overall increase in pulp yield could improve dewatering as a sheet of a certain weight will contain fewer fibres, giving a more open sheet structure. It was therefore of interest to measure the dewatering properties of low grammage handsheets (20 g/m2) under conditions mimicking the tissue paper machine dewatering processes, and sheet strength properties, WRV, °SR and fibre dimensions were also studied. The results showed that the positive influence of overall yield increase dominated over the negative influence of an increase in hemicellulose content on the dewatering properties, particularly at lower refining energy levels. Moreover, higher yield and higher hemicellulose content pulps had a higher tensile index at the same dryness. A given tensile index was achieved with less refining energy. The results indicate that increased yield and hemicellulose content by modification of the kraft pulping process will result in a pulp with a potential to improve tissue paper quality.
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Research context

OpenAlex topics: Advanced Cellulose Research Studies · Lignin and Wood Chemistry · Material Properties and Processing

SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.

Affiliations

SCA R&D Centre , Sidsjövägen 2, P. O. Box 716, SE-851 21 Sundsvall , Sweden

present address: FSCN Mittuniversitetet , SE-851 70 Sundsvall , Sweden

FSCN Mittuniversitetet , SE-851 70 Sundsvall , Sweden

Department of Engineering and Chemical Sciences , Karlstad University , SE-651 88 Karlstad , Sweden

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