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Licensed Unlicensed Requires Authentication Published by De Gruyter February 1, 2020

Determination of relative solids concentration in homogeneous dual component pulp-filler suspension by multi-spectrophotometer

Ilpo Niskanen ORCID logo, Viviane Forsberg, Daniel Zakrisson, Birgitta A. Engberg, Rauno Heikkilä and Göran Thungström


The concentration of fibers and fillers in the pulp suspension is an important parameter in the monitoring process. This paper proposes a versatile optical measurement system to estimate the concentration of a solids mixture in water. The geometry used in a multi-spectrophotometer (MSM) enables the controlled observation of transmission, and forward scattering light from the suspension in the UV-visible spectral range. We have developed the new fibers mixing system which gives a homogenous distribution of the fines and fillers making it possible to increase the reproducibility and accuracy of the measurement. The data analysis is based on the Beer-Lambert law and CIELAB color space equations. The results show that the proposed method is accurate for measuring the fines and filler concentrations in multicomponent suspensions.

Funding source: Stiftelsen för Kunskaps- och Kompetensutveckling

Award Identifier / Grant number: 2150361

Funding source: Stiftelsen Åforsk

Award Identifier / Grant number: 18-281

Funding statement: We gratefully acknowledge funding from the Knowledge Foundation of Sweden (2150361). The Alice and Knut Wallenberg foundation through the Wallenberg Wood Science Center, ÅForsk Foundation (grant no. 18-281), J. Gust Richert Foundation (grant no. 2018-00459) and the Swedish Graphic Companies Federation.

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


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Received: 2018-09-25
Accepted: 2019-11-21
Published Online: 2020-02-01
Published in Print: 2020-03-26

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