Solids Introduction and Mixing

The generally accepted melting model for SSEs is the one described by Tadmor and Gogos [6] wherein the passive solid bed moves axially downstream being gradually compressed in the transition sections such that a melt film forms at the barrel wall by a combination of direct heat transfer through this wall and friction of the unmelted 

Screws by themselves do not provide much mixing. In an SSE, the requirement for developing pressure to form the extrudate leads to some cross-channel mixing. 

Shearing forces vhll be required to break up agglomerates. The level of these shearing forces will depend upon the nature of the filler. For example, intense shearing is usually required when dispersing carbon black. Even more severe shearing will be needed to disperse montmorillonite clay into nanosized platelets. 

In general, all the enhancers improve the distribution of filler by a series of divisions and recombinations. Simple shear mixing should be interrupted by a 

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