Continuous Preparation and Properties of Silica/Rubber Composite Using Serial Modular Mixing

Influence of process parameters of a continuous final mixer on the properties of carbon black/rubber composites

As the final stage of the mixing process, the final mixing has a profound impact on the properties of rubber compounds. The influence of the process parameters of a continuous final mixer on the properties of carbon black/rubber composites is studied. It is found that there are two factors affecting the performance of the composite: the rotating speed of the dual rotors and the temperature of the continuous final mixer. When the temperature is unchanged, the extruding temperature of the final-mixing rubber compound increases with increasing rotating speed, and the Mooney viscosity, T10, T90 and rolling resistance gradually decrease. The Payne effect decreases first and then increases, and the overall trend gradually decreases. When the rotating speed is constant, as the temperature of the continuous final mixer rises, the extruding temperature also rises, and the temperature difference between feeding and extruding increases. Mooney viscosity and tensile strength increase. The Payne effect is more significant. T10, T90 and rolling resistance gradually decrease. The M300 of a vulcanized sample shows the following laws: When the control temperature is low, the influence of rotational speed is small, the fluctuation range is small, and has a steady rising trend; however, when the temperature is higher, M300 fluctuates greatly under the influence of rotational speed. The optimal process parameters of the rubber continuous final mixer are determined: the double rotor speed is 30RPM, and the temperature control temperature is 60–70 °C.

Enhancement of Green Tires Performance through Ultrasound-Assisted Mixing

Combined with the traditional internal mixing process, a custom-built ultrasonic generator was introduced in this study. The effect of ultrasonic parameters on the comprehensive performance of tread rubber formulations was investigated. Compared to the traditional mixing process without ultrasonic wave loading, the introduction of ultrasonic enhanced the dispersion and distribution of composite particles in the rubber matrix and improved the overall performance of rubber products. The devil’s triangle relationship among the rolling resistance, wet skid resistance, and abrasion resistance of tires was improved. When the wet skid resistance was slightly lost, the rolling resistance and wear rate were effectively reduced. This study provides new insights into a strategy for optimizing the mixing process of the traditional internal mixer, reducing vehicle emissions, extending the service life of tires, and promoting the development of green tires.

Wet Mixing with Organic Solvent for Synthesized cis-1,4-Polyisoprene-Based Rubber Composites

In this work, well-dispersed fumed SiO₂/cis-1,4-polyisoprene rubber (IR) masterbatch was first obtained through an effective wet mixing method, and the properties of the corresponding vulcanizate were studied. Before curing with activator and sulfur, IR solution was blended and co-coagulated with SiO₂ suspension modified by bis(3-trimethoxysilypropyl) tetrasulfide in n-hexane. The modification of TESPT imparted evenly distributed SiO₂ particles in IR and improved interfacial binding among SiO₂ and IR. Hence, the prepared compound presented better processability and the corresponding vulcanizate presented higher physical performance, including higher tensile strength, lower heat buildup, and better fatigue resistance than that prepared in the dry mixing method. Additionally, higher wet skid resistance and lower rolling resistance could be observed in fabricated SiO₂/IR vulcanizate. The employed wet mixing method is economical and efficient, which is promising in preparing rubber composites with comprehensive performance.

Numerical Optimization Simulation of Synchronous Four-Wing Rotor

The mixer is the most widely used batch mixing equipment in the rubber industry. The rotor is a core component and has a great impact on the mixing effect of the equipment. The current rotor structure design is done empirically, being tightly dependent on practical experience. This paper proposes a method for optimizing the rotor structure by using optimization algorithms combined with numerical simulation technology. Using MATLAB software, a parametric design program for synchronous rotors and a set of optimization programs for the particle swarm optimization (PSO) algorithm were written. The global distribution index was used as the fitness function to optimize the synchronous rotor configuration. A comparative analysis of the rotors before and after optimization shows that the optimization process is feasible, and the results are reliable. This provides new ideas for the design and development of mixer rotors.

Optimization of Serial Modular Continuous Mixing Process Parameters for Natural Rubber Composites Reinforced by Silica/Carbon Black

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.