Experimental Studies and Modeling of Development of Dispersion and Fiber Damage in Continuous Compounding

Abstract

Abstract An experimental study of mixing of various particulates into synthetic elastomers and polypropylene is presented. For the elastomers, a batch internal mixer and a commercial continuous mixer were used to disperse various small particles including silica, carbon black, and CaCO3. For the polypropylene, this same continuous mixer plus a Buss Kneader, co-rotating twin screw extruder and an intermeshing counter-rotating twin screw extruder with different modular screw configurations were used to follow the dispersion of CaCO3. The breakage of glass fibers in these machines was also followed. Generally the most severe breakage of agglomerates and glass fiber was by modular intermeshing counter-rotating screws with special Leistritz elements. A model was developed for breakdown of agglomerates and fibers. The agreement with experiment was promising.