Tailoring the microporous structure of fibre materials with foam carrier

Research output: Contribution to conferenceConference AbstractScientific

Abstract

Use of foam as a material carrier in the manufacturing of novel paper-like structures has recently been studied intensively [1]. Tailoring the microporous structure requires control over various physical and chemical foam properties including air content, bubble size, interfacial rheology and foam stability. The relative importance of these factors has been studied in mixing experiments and in laboratory forming of sheet structures using foam-fibre mixtures. In axial mixing [2], the bubble size is affected by several physical factors such as rotational speed, air content and surface tension. At high shear rates, the bubble size becomes small and the importance of surface interactions increases affecting the rheological behaviour described by the Herschel-Bulkley equation. The inclusion of natural fibres (like wood fibres) to the mixing environment reduces the mean bubble size. However, the inclusion of the regenerated fibres (e.g. viscose fibres) does not affect the mean bubble size in the same way. The likely reason behind this behaviour is the rough surfaces of the natural fibres (and their fine particle fraction) that lead to high contact forces between the fibres and the foam bubbles [2,3]. The bubble size is inherited in the formed microstructure as a characteristic mean pore size after the foam carrier is removed from the foam-fibre system. With the same surfactant, bigger bubbles increase the mean pore size. Besides the above physical parameters, we have studied the effect of different surfactant types on the bubble size, interfacial rheology and the microstructure. The effects of the chemically different surfactants can exceed that of the varying bubble size leading to a decrease in the mean pore size even though the average bubble size increases. This provides an additional handle to the tailoring of the microstructure of the end product. 1) A. M. Al-Qararah, A. Ekman, T. Hjelt, J. A. Ketoja, H. Kiiskinen, A. Koponen, J. Timonen, A unique microstructure of the fiber networks deposited from foam-fiber suspensions. Colloids and Surfaces A: Physicochem. Eng. Aspects 482, 544-553 (2015). 2) A. M. Al-Qararah, T. Hjelt, A. Koponen, A. Harlin, J. A. Ketoja, Response of wet foam to fibre mixing. Colloids and Surfaces A: Physicochem. Eng. Aspects 467, 97-106 (2015). 3) A. Jäsberg, P. Selenius, A. Koponen, Flow rheology of fibre-laden aqueous foams. Proceedings of Papercon 2015, 19.4 - 22.5.2015, Atlanta, Georgia.
Original languageEnglish
Publication statusPublished - 2016
EventEUFOAM 2016 Conference - Dublin, Ireland
Duration: 3 Jul 20166 Jul 2016

Conference

ConferenceEUFOAM 2016 Conference
Abbreviated titleEUFOAM
CountryIreland
CityDublin
Period3/07/166/07/16

Fingerprint

bubbles
foams
microstructure
rheology
surfactants
natural fibers
colloids
surface interactions
viscose
air
wood fibers
surface tension
shear stress
manufacturing

Keywords

  • foam
  • fibre
  • material
  • structure
  • bubble
  • pore
  • mixing

Cite this

@conference{40af3fb9bf1f47b6808971b329729f05,
title = "Tailoring the microporous structure of fibre materials with foam carrier",
abstract = "Use of foam as a material carrier in the manufacturing of novel paper-like structures has recently been studied intensively [1]. Tailoring the microporous structure requires control over various physical and chemical foam properties including air content, bubble size, interfacial rheology and foam stability. The relative importance of these factors has been studied in mixing experiments and in laboratory forming of sheet structures using foam-fibre mixtures. In axial mixing [2], the bubble size is affected by several physical factors such as rotational speed, air content and surface tension. At high shear rates, the bubble size becomes small and the importance of surface interactions increases affecting the rheological behaviour described by the Herschel-Bulkley equation. The inclusion of natural fibres (like wood fibres) to the mixing environment reduces the mean bubble size. However, the inclusion of the regenerated fibres (e.g. viscose fibres) does not affect the mean bubble size in the same way. The likely reason behind this behaviour is the rough surfaces of the natural fibres (and their fine particle fraction) that lead to high contact forces between the fibres and the foam bubbles [2,3]. The bubble size is inherited in the formed microstructure as a characteristic mean pore size after the foam carrier is removed from the foam-fibre system. With the same surfactant, bigger bubbles increase the mean pore size. Besides the above physical parameters, we have studied the effect of different surfactant types on the bubble size, interfacial rheology and the microstructure. The effects of the chemically different surfactants can exceed that of the varying bubble size leading to a decrease in the mean pore size even though the average bubble size increases. This provides an additional handle to the tailoring of the microstructure of the end product. 1) A. M. Al-Qararah, A. Ekman, T. Hjelt, J. A. Ketoja, H. Kiiskinen, A. Koponen, J. Timonen, A unique microstructure of the fiber networks deposited from foam-fiber suspensions. Colloids and Surfaces A: Physicochem. Eng. Aspects 482, 544-553 (2015). 2) A. M. Al-Qararah, T. Hjelt, A. Koponen, A. Harlin, J. A. Ketoja, Response of wet foam to fibre mixing. Colloids and Surfaces A: Physicochem. Eng. Aspects 467, 97-106 (2015). 3) A. J{\"a}sberg, P. Selenius, A. Koponen, Flow rheology of fibre-laden aqueous foams. Proceedings of Papercon 2015, 19.4 - 22.5.2015, Atlanta, Georgia.",
keywords = "foam, fibre, material, structure, bubble, pore, mixing",
author = "Tuomo Hjelt and Al-Qararah, {Ahmad, M.} and Heikki Pajari and Antti Koponen and Christiane Laine and Timo Lappalainen and Arja Paananen and Ketoja, {Jukka A.}",
note = "SDA: SHP: Bioeconomy Project code: 104479 ; EUFOAM 2016 Conference, EUFOAM ; Conference date: 03-07-2016 Through 06-07-2016",
year = "2016",
language = "English",

}

Tailoring the microporous structure of fibre materials with foam carrier. / Hjelt, Tuomo; Al-Qararah, Ahmad, M.; Pajari, Heikki; Koponen, Antti; Laine, Christiane; Lappalainen, Timo; Paananen, Arja; Ketoja, Jukka A.

2016. Abstract from EUFOAM 2016 Conference, Dublin, Ireland.

Research output: Contribution to conferenceConference AbstractScientific

TY - CONF

T1 - Tailoring the microporous structure of fibre materials with foam carrier

AU - Hjelt, Tuomo

AU - Al-Qararah, Ahmad, M.

AU - Pajari, Heikki

AU - Koponen, Antti

AU - Laine, Christiane

AU - Lappalainen, Timo

AU - Paananen, Arja

AU - Ketoja, Jukka A.

N1 - SDA: SHP: Bioeconomy Project code: 104479

PY - 2016

Y1 - 2016

N2 - Use of foam as a material carrier in the manufacturing of novel paper-like structures has recently been studied intensively [1]. Tailoring the microporous structure requires control over various physical and chemical foam properties including air content, bubble size, interfacial rheology and foam stability. The relative importance of these factors has been studied in mixing experiments and in laboratory forming of sheet structures using foam-fibre mixtures. In axial mixing [2], the bubble size is affected by several physical factors such as rotational speed, air content and surface tension. At high shear rates, the bubble size becomes small and the importance of surface interactions increases affecting the rheological behaviour described by the Herschel-Bulkley equation. The inclusion of natural fibres (like wood fibres) to the mixing environment reduces the mean bubble size. However, the inclusion of the regenerated fibres (e.g. viscose fibres) does not affect the mean bubble size in the same way. The likely reason behind this behaviour is the rough surfaces of the natural fibres (and their fine particle fraction) that lead to high contact forces between the fibres and the foam bubbles [2,3]. The bubble size is inherited in the formed microstructure as a characteristic mean pore size after the foam carrier is removed from the foam-fibre system. With the same surfactant, bigger bubbles increase the mean pore size. Besides the above physical parameters, we have studied the effect of different surfactant types on the bubble size, interfacial rheology and the microstructure. The effects of the chemically different surfactants can exceed that of the varying bubble size leading to a decrease in the mean pore size even though the average bubble size increases. This provides an additional handle to the tailoring of the microstructure of the end product. 1) A. M. Al-Qararah, A. Ekman, T. Hjelt, J. A. Ketoja, H. Kiiskinen, A. Koponen, J. Timonen, A unique microstructure of the fiber networks deposited from foam-fiber suspensions. Colloids and Surfaces A: Physicochem. Eng. Aspects 482, 544-553 (2015). 2) A. M. Al-Qararah, T. Hjelt, A. Koponen, A. Harlin, J. A. Ketoja, Response of wet foam to fibre mixing. Colloids and Surfaces A: Physicochem. Eng. Aspects 467, 97-106 (2015). 3) A. Jäsberg, P. Selenius, A. Koponen, Flow rheology of fibre-laden aqueous foams. Proceedings of Papercon 2015, 19.4 - 22.5.2015, Atlanta, Georgia.

AB - Use of foam as a material carrier in the manufacturing of novel paper-like structures has recently been studied intensively [1]. Tailoring the microporous structure requires control over various physical and chemical foam properties including air content, bubble size, interfacial rheology and foam stability. The relative importance of these factors has been studied in mixing experiments and in laboratory forming of sheet structures using foam-fibre mixtures. In axial mixing [2], the bubble size is affected by several physical factors such as rotational speed, air content and surface tension. At high shear rates, the bubble size becomes small and the importance of surface interactions increases affecting the rheological behaviour described by the Herschel-Bulkley equation. The inclusion of natural fibres (like wood fibres) to the mixing environment reduces the mean bubble size. However, the inclusion of the regenerated fibres (e.g. viscose fibres) does not affect the mean bubble size in the same way. The likely reason behind this behaviour is the rough surfaces of the natural fibres (and their fine particle fraction) that lead to high contact forces between the fibres and the foam bubbles [2,3]. The bubble size is inherited in the formed microstructure as a characteristic mean pore size after the foam carrier is removed from the foam-fibre system. With the same surfactant, bigger bubbles increase the mean pore size. Besides the above physical parameters, we have studied the effect of different surfactant types on the bubble size, interfacial rheology and the microstructure. The effects of the chemically different surfactants can exceed that of the varying bubble size leading to a decrease in the mean pore size even though the average bubble size increases. This provides an additional handle to the tailoring of the microstructure of the end product. 1) A. M. Al-Qararah, A. Ekman, T. Hjelt, J. A. Ketoja, H. Kiiskinen, A. Koponen, J. Timonen, A unique microstructure of the fiber networks deposited from foam-fiber suspensions. Colloids and Surfaces A: Physicochem. Eng. Aspects 482, 544-553 (2015). 2) A. M. Al-Qararah, T. Hjelt, A. Koponen, A. Harlin, J. A. Ketoja, Response of wet foam to fibre mixing. Colloids and Surfaces A: Physicochem. Eng. Aspects 467, 97-106 (2015). 3) A. Jäsberg, P. Selenius, A. Koponen, Flow rheology of fibre-laden aqueous foams. Proceedings of Papercon 2015, 19.4 - 22.5.2015, Atlanta, Georgia.

KW - foam

KW - fibre

KW - material

KW - structure

KW - bubble

KW - pore

KW - mixing

M3 - Conference Abstract

ER -

Hjelt T, Al-Qararah AM, Pajari H, Koponen A, Laine C, Lappalainen T et al. Tailoring the microporous structure of fibre materials with foam carrier. 2016. Abstract from EUFOAM 2016 Conference, Dublin, Ireland.