Skip to content
Licensed Unlicensed Requires Authentication Published by De Gruyter September 11, 2020

Production of a fine fraction using micro-perforated screens

  • Elisabeth Björk ORCID logo EMAIL logo , Mikael Bouveng and Hannes Vomhoff

Abstract

The objective for this work was to investigate the possibility to use a pressure screen equipped with a micro-perforated screen basket to produce a fine fraction from bleached chemical pulp. Trials were performed with unrefined bleached chemical hardwood pulp, and with unrefined and refined bleached chemical softwood pulp. The effect of feed concentration, feed flow, and volumetric fine fraction flow was evaluated. The difference between the fine fraction (i. e. the particles passing the screen) and the feed was analysed by studying the fibre morphology. The results showed that high feed concentration was positive for both the fine fraction concentration and the separation efficiency. A higher fine fraction concentration was also obtained when using hardwood pulp, which was explained by the shorter fibre length. Refining of the pulp prior to the fractionation proved beneficial, as a larger share of the refined pulp passed the screen, resulting in a twice as high concentration of the fine fraction when compared to unrefined pulp.

Funding statement: Financial support was received by Financial support was received by Stiftelsen för Kunskaps- och Kompetensutveckling, the Swedish Energy Agency, and the industrial partners participating in the CREPs (Production Concepts for Raw Material and Energy Efficient Products) research project at Rise: BillerudKorsnäs, Kadant NOSS, Metsä Board and Stora Enso.

Acknowledgments

The authors are grateful for the financial support from RISE Research Institutes of Sweden, The Knowledge Foundation and the companies participating in the CREPs project (Production Concepts for Raw Material and Energy Efficient Products) between 2010 and 2014. We also thank the staff at the pilot plant.

  1. Conflict of interest: The authors declare no conflicts of interest.

References

Ankerfors, M., Lindström, T., et al. (2014) The use of microfibrillated cellulose in fine paper manufacturing – Result from a pilot scale papermaking trial. Nord. Pulp Pap. Res. J. 29(3):476–483.10.3183/npprj-2014-29-03-p476-483Search in Google Scholar

Asikainen, S., Fuhrmann, A., et al. (2010) Birch pulp fractions for fine paper and board. Nord. Pulp Pap. Res. J. 25(11):15–22.10.3183/npprj-2010-25-03-p269-276Search in Google Scholar

Bäckström, M., Kolar, M., et al. (2008) Characterisation of fines from unbleached kraft pulps and their inpact on sheet properties. Holzforschung 62:546–552.10.1515/HF.2008.081Search in Google Scholar

Ferluc, A., Lanouette, R., et al. (2010) Optimum refining of TMP pulp by fractionation after the first refining stage. Appita J. 63(4):308–314.Search in Google Scholar

Fischer, W., Mayr, M., et al. (2017) Pulp fines – Characterisation, sheet formation, and comparison to microfibrillated cellulose. Polymers 9(8).10.3390/polym9080366Search in Google Scholar PubMed PubMed Central

Gavelin, G. Papp och kartong. Skogsindustrins utbildning i Markaryd AB, Markaryd, 1995.Search in Google Scholar

Hyll, K. (2015) Size and shape characterisation of fines and filler – a review. Nord. Pulp Pap. Res. J. 30(3):466–487.10.3183/npprj-2015-30-03-p466-487Search in Google Scholar

Kumar, S., Julien Saint Amand, F., et al. (2014) Micro-hole pressure screening and hydrocyclone fractionation applied to mechanical pulps for fractions generation. In: IMPC 2014. 29th. International Mechanical Pulping Conference 2014. Helsinki, Finland.Search in Google Scholar

Lobben, T.H. (1977) Effekter av finstoff på styrkeegenskaper hos kjemiske massor (Effect of fines on strength properties of chemical pulp). Nor. Skogind. 77(4):93–97.Search in Google Scholar

Mayr, M., Eckhart, R., et al. (2017) Improved microscopy method for morphological characterisation of pulp fines. Nord. Pulp Pap. Res. J. 32(2):244–252.10.3183/npprj-2017-32-02-p244-252Search in Google Scholar

Olson, J. The effect of fibre length on passage through narrow apertures. University of British Columbia, 1996.Search in Google Scholar

Olson, J. (2001) Fibre length fractionation caused by pulp screening, slotted screen plate. J. Pulp Pap. Sci. 27(8):255–261.Search in Google Scholar

Olson, J., Allison, B., et al. (1999) Fibre length fractionation caused by pulp screening, smooth-hole screen plates. In: PAPTAC 85th annual meeting 1999. Montreal, Canada. pp. B207–B212.Search in Google Scholar

Olson, J., Wherret, G. (1998) A model of fibre fractionation by slotted screen apertures. J. Pulp Pap. Sci. 24(12):398–403.Search in Google Scholar

Olson, J.A., Roberts, N., et al. (1998) Fibre length fractionation caused by pulp screening. J. Pulp Pap. Sci. 24(12):393–397.Search in Google Scholar

Panula-Ontto, S. (2002) Fractionation of unbleached kraft pulp – pressure screening using smooth-hole screen baskets. In: KCL reports 2625, STFI report CHEM 56. Ed. KCL.Search in Google Scholar

Retulainen, E., Luukko, K., et al. (2002) Papermaking quality of fines from different pulps: the effect of size, shape and chemical composition. Appita J. 55(6):457–460.Search in Google Scholar

Retulainen, E., Nieminen, K., et al. (1993) Enhancing strength properties of kraft and CTMP fibre network. Appita J. 46(1):31–38.Search in Google Scholar

Taipale, T., Österberg, M., et al. (2010) Effect of microfibrillated cellulose and fines on the drainage of kraft pulp suspension and paper strength. Cellulose 17(5):1005–1020.10.1007/s10570-010-9431-9Search in Google Scholar

Received: 2020-02-07
Accepted: 2020-08-08
Published Online: 2020-09-11
Published in Print: 2020-11-18

© 2020 Walter de Gruyter GmbH, Berlin/Boston

Downloaded on 28.3.2024 from https://www.degruyter.com/document/doi/10.1515/npprj-2020-0012/html
Scroll to top button