EFFECT OF FLIGHT CLEARANCE ON MIXING CHARACTERISTICS IN PLASTICATING EXTRUDERS.

This paper reports experimental data on the effect of flight clearance on the mixing characteristics of a laboratory extruder to assist in the proof of the rapidly developing theories of residence time distribution (RTD) and strain distribution functions (SDF). It is demonstrated that utilizing the RTD and SDF functions can be useful in analyzing mixing and dispersion systems in plasticating extruders. There is a need to correlate these techniques with independent quantitative measurements of mixing quality. Additional research is also needed in the development of laboratory techniques for measuring SDF experimentally, which is a very difficult problem. A diagram of the experimental extrusion system used in the investigation reported is included and test results are plotted and tabulated.