A comparative study of dispersing a polyamide 6 into a polypropylene melt in a Buss Kneader, continuous mixer, and modular intermeshing corotating and counter-rotating twin screw extruders

We have made a study of the development of phase morphology of an immiscible blend(75/25)(polypropylene–polyamide-6) for different types of continuous mixers including (i) Buss Kneader, (ii and iii) modular intermeshing corotating and counter-rotating twin screw extruders, and (iv) NEX-T Kobelco Continuous Mixer. Comparisons are made using different screw configurations for each machine. Generally, in comparison of the different machines, the intermeshing counter-rotating twin screw extruder produced the finest dispersed morphology. Using a droplet breakup kinetic model, we interpreted the blend dispersed phase droplet breakdown rate and coalescence rate. In comparison with our earlier study of the continuous mixing of agglomerates of CaCO3 particles the polymer droplet breakup rate was smaller than that of the particle agglomerates and the coalescence rates of droplets were many times greater than the particle reagglomerates rates. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers