In the tire industry, the combination of carbon black and silica is commonly utilized to improve the comprehensive performance of natural rubber so as to realize the best performance and cost-effectiveness. The corresponding mixing is divided into three processes (initial mixing, delivery, reactive mixing) by the serial modular continuous mixing method, thus achieving more accurate control of the mixing process, higher production efficiency and better performance. Moreover, the optimization of serial modular continuous mixing process parameters can not only improve the performance of composite materials, but help people understand the physical and chemical changes and the reinforcing mechanism of fillers in the mixing process. In this paper, the relationship among the parameters of eight processes and filler network structure, tensile strength, chemical reinforcing effect and tear resistance was explored through experiments. The deep causes of performance changes caused by parameters were analyzed. Consequently, the best process condition and the ranking of the influencing factors for a certain performance was obtained. Furthermore, the best preparation process of natural rubber (NR)/carbon black/silica composite was achieved through comprehensive analysis.

In order to efficiently prepare high-performance silica/rubber composites for use in the tread of semi-steel radial tires, a serial modular continuous mixer was designed according to the principle of modular functionalization. The modular structure and serial process helped control the accuracy of the silanization reaction. Synchronous four-wing serrated rotors and reverse meshing reaction mixing twin-rotors utilized shear flow and elongation flow to improve the dispersion. In this paper, the mechanism of serial modular continuous mixing was analyzed, and the influence of the core reaction mixing zone (various mixing elements) on silica-filled compounds was investigated by cooling visualization experiments, including dispersion, and the silanization reaction degree. Meanwhile, a comparative experiment between serial mixing and two-stage mixing was conducted, which showed that the serial process comprehensively improved the dispersion, mechanical properties, and dynamic mechanical properties of silica/rubber vulcanizate.