Abstract
Wet foam is an excellent carrier phase to produce
particle or fibre structures. Thus, it is important to
know how particles or fibres affect foam properties. We
study foams generated by axially agitated mixing with
60-80% air content. The shear rate and resulting
capillary number in mixing are very high compared to
similar parameters in typical foam rheology studies.
Onset of a flow macro-instability is observed at high
rotation speeds both with and without cellulose fibres.
The air content of the foam is strongly affected by this
instability. By describing the effect of the air content
on the stability of bubble interfaces, we explain the
bubble size for broad ranges of rotation speed and
surface tension. Added fibres usually reduce the bubble
size for a fixed rotation speed. After the flow
macro-instability, not only the air content but also the
bubble size increases with reduced surface tension.
Beyond the instability, the effect of fibres on foam
properties becomes minor.
Original language | English |
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Publication status | Published - 2014 |
Event | 9th Annual European Rheology Conference, AERC 2014 - Karlsruhe, Germany Duration: 8 Apr 2014 → 11 Apr 2014 |
Conference
Conference | 9th Annual European Rheology Conference, AERC 2014 |
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Abbreviated title | AERC |
Country/Territory | Germany |
City | Karlsruhe |
Period | 8/04/14 → 11/04/14 |
Keywords
- foam
- fibre
- mixing
- air content
- bubble size
- flow