Dispersion Carreau equation

It is not uncommon to encounter emulsions, foams, and suspensions, both in nature and in industry, that contain polymers. If the polymer concentration is high enough, and the dispersed species concentration low enough, the overall viscosity may be better described by the contribution from the polymer solution than that from the dispersed species. One commonly employed equation for describing the viscosity of polymer solutions is the Carreau equation,... 

Using finite element techniqnes, a mathematical model was developed for the two-dimensional analysis of non-isothermal and transient flow and mixing of a generalised Newtonian fluid with an inert filler. The model could incorporate no-slip, partial-slip or perfect-slip wall conditions using a universally applicable numerical technique. The model was used to simulate the convection of carbon black with flowing rubber in the dispersive section of a tangential rotor (Banbury) mixer. The Carreau equation was used to model the rheological behaviour of the fluid in this example. 31 refs. 

Constitutive equations were applied to simulate viscoelasticity of concentrated food polymer dispersions. Some fundamental and empirical models have been discussed in Section V. Among them, the Bird-Carreau constitutive model [Eqs. (89-94)] have been used for food polymer dispersions (Kokini et ai, 1984 Kokini and Plutchok, 1987b Plutchok and Kokini, 1986). 

Using these empirical equations in conjunction with the predictions of the Bird-Carreau model, it is possible to predict t/ and An example of such a plot is shown in Fig. 24 for a 1.0% CMCguar blend (3 1). Experimental data are superimposed on these plots to judge the aptness of the model. The steady shear viscosity 17 and the dynamic viscosity 17 are well predicted in the shear rate range of 0.1 to 100 sec . The experimental data, as well as the theoretical prediction, portray commonly observed behaviors by polymeric dispersions. In this instance, 17 and rf for this blend ratio tend to some value, a property suggested by the Bird-Carreau model at low shear rate (Kokini et al, 1984). 

Lee et al. [2007] studied the rheological behavior of poly(ethylene-co-vinyl acetate) (EVAc 40 wt% VAc) and its CPNC with < 10 wt% C30B the tests were conducted under steady-state and small oscillatory shear flow. The samples were prepared by melt compounding at 110 C for 25 min, which resulted in a high degree of dispersion. The flow behavior was quite regular, well described by the Carreau-Yasuda equation [Carreau, 1968,1972 Yasuda, 1979] ... 

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