Elongation flow mixer

Comparisons were made by Utracki and Sepehr [6] between single and twin screw extruders for compounding nano-clays into polyamide-6 and PP, in which the elongational flow mixer (EFM) described in Chapter 15, was used. The combination of single screw extruder plus EFM produced better dispersions than were achieved with a twin screw extruder with or without an EFM. 

Much of this analysis is aimed at understanding the nature of velocity profiles, shear and elongational flow behaviour of fluid elements experiencing the unique mixing action within internal mixers. Due to their importance in the rubber in-... 

Another consequence of the high N] offered by elastomers is that in the unidirectional flow regions of the mixer an elongational flow is surely combined with the shearing flow, as illustrated in Figure 4. 

Polymer blends are produced by mixing incompatible polymers in the liquid state. In blenders such as two-roll mills and internal mixers shear as well as elongational flows occur and in most cases the flow field is rather complex. 

Flow numbers are achieved as high as 0.95, indicating that strong elongational flow can be generated in the new mixers. Similarly, Fig. 8.90 shows the magnitude of the rate of deformation tensor of the particle as it flows through the system. 

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