Usage of Fines-enriched pulp to increase strength in CTMP
2017 (English)In: Paper Conference and Trade Show, PaperCon 2017: Renew, Rethink, Redefine the Future, TAPPI Press, 2017, Vol. 3, p. 1607-1631Conference paper, Published paper (Other academic)
Abstract [en]
Fines-enriched pulp (FE-pulp) was benchmarked against glue pulp as strength agent in eucalypt CTMP. FE-pulp was produced by combining high intensity multiple-pass refining with a fractionation in a microperforated screen basket. The fraction passing through the holes of the screen is the FE-pulp. The FE-pulp comprises of secondary fines, created in the refiner, and flexible, fibrillated highly-refined fibres or fibre fragments. Glue pulp is highly refined kraft pulp, commonly added as a strength agent in middle plies of board products, or between plies to increase the plybond. Equal amounts of FE-pulp and glue pulp were added to the original CTMP as well as to washed CTMP, where most of the CTMP-fines had been removed. The effects of the strength agents were evaluated using laboratory sheets. Both glue pulp and FE-pulp increased the strength of the CTMP sheets. The bulk of the sheets decreased however. When 5 % FE-pulp was added, the tensile index increased by more than 50 %, and the tensile energy absorption and z-strength increased by more than 100 %. FE-pulp proved to be twice as effective as glue pulp. The addition of 5 % FE-pulp resulted in the same relative strength increase as an addition of 10 % glue pulp. The washed CTMP lost all strength when the CTMP-fines content was reduced from 17 % to 3% through washing. The addition of 5 % FE-pulp restored the strength values, and at a higher bulk. The drainability in terms of CSF of that stock was much higher when compared to the original pulp.
Place, publisher, year, edition, pages
TAPPI Press, 2017. Vol. 3, p. 1607-1631
Keywords [en]
fines, pulp, refining, CTMP, chemithermomechanical pulp, strength
National Category
Paper, Pulp and Fiber Technology
Identifiers
URN: urn:nbn:se:ri:diva-33331Scopus ID: 2-s2.0-85041539440OAI: oai:DiVA.org:ri-33331DiVA, id: diva2:1186476
Conference
Paper Conference and Trade Show: Renew, Rethink, Redefine the Future, PaperCon 2017; Minneapolis; United States; 23 April 2017 through 26 April 2017
2018-02-282018-02-282023-05-16Bibliographically approved