The effect of bubbles on viscosity
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Today I measured the viscosity of several batches of resin, first without shaking and then after shaking. There were no bubbles in the sample taken without shaking, while the sample shaken contained many small bubbles; as a result, the viscosity values obtained were quite different, with some differences being as much as double. Do you think bubbles can have such a significant impact on viscosity? I am using a rotational viscometer; the normal viscosity of the resin is around 1000 MP·s. Last edited by QXZ-1966 on 2009-3-24 at 11:14.]
For reference: http://www.ilib.cn/A-QCode~wlsy200112011.html At the microscopic level, when two bubbles come close to each other, a liquid film is formed between them. The properties of the fluid itself and those of the interface (such as surface tension, surface viscosity, and intermolecular forces) all affect the rate at which liquid is expelled from this film, thereby influencing the rate of bubble coalescence... According to available data, bubbles have an impact on viscosity measurements.
Bubbles have a significant impact on viscosity; therefore, a vacuum degassing process must be carried out before measuring viscosity