A1 Journal article (refereed)
Online measurement of floc size, viscosity, and consistency of cellulose microfibril suspensions with optical coherence tomography (2021)

Lauri, J., Haavisto, S., Salmela, J., Miettinen, A., Fabritius, T., & Koponen, A. I. (2021). Online measurement of floc size, viscosity, and consistency of cellulose microfibril suspensions with optical coherence tomography. Cellulose, 28(6), 3373-3387. https://doi.org/10.1007/s10570-021-03745-6

JYU authors or editors

Publication details

All authors or editors: Lauri, Janne; Haavisto, Sanna; Salmela, Juha; Miettinen, Arttu; Fabritius, Tapio; Koponen, Antti I.

Journal or series: Cellulose

ISSN: 0969-0239

eISSN: 1572-882X

Publication year: 2021

Publication date: 18/02/2021

Volume: 28

Issue number: 6

Pages range: 3373-3387

Publisher: Springer

Publication country: Netherlands

Publication language: English

DOI: https://doi.org/10.1007/s10570-021-03745-6

Publication open access: Openly available

Publication channel open access: Partially open access channel

Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/74353

Abstract

In this study, cellulose microfibril (CMF) suspensions were imaged during pipe flow at consistencies of 0.4%, 1.0%, and 1.6% with optical coherence tomography (OCT) to obtain images of the structure and the local velocity of the suspension. The viscosities obtained by combining pressure loss measurement with the OCT velocity data showed typical shear thinning behavior and were in excellent agreement with viscosities obtained with ultrasound velocity profiling. The structural OCT images were used to calculate the radial and the axial floc sizes of the suspension. A fit of power law to the geometrical floc size–shear stress data gave the same power law index for all consistencies, suggesting that floc rupture dynamics is independent of consistency. The dependence of viscosity and floc size on shear stress was similar, indicating that the shear thinning behavior of CMF suspensions is closely related to the rupture dynamics of flocs. The results also showed that an apparent attenuation coefficient of the OCT signal can be used to determine the consistency of CMF suspensions.

Keywords: cellulose; microfibres; suspensions (chemistry); rheology; viscosity; optical coherence tomography

Free keywords: cellulose microfibrils; CMF; rheology; viscosity; flocculation; floc size; consistency; optical coherence tomography; OCT

Contributing organizations

Ministry reporting: Yes

Reporting Year: 2021

JUFO rating: 2