Wet continuous mixing technology and extrusion rheological properties of carbon black/natural rubber composites

Abstract In order to solve the problems of dust, low mixing efficiency, and poor quality stability in dry mixing and continuous mixing, this study combined the flocculation extrusion technology with continuous mixing technology of carbon black/additives/natural rubber composites. The flocculation of latex was achieved by carbon black itself and the shearing of the twin screw. The continuous mixing was carried out in a double‐rotor continuous mixer, which was composed of functional elements such as the exhaust section and extrusion section. The results showed that the technology promoted the formation of the filler‐rubber network, the sensitivity of viscosity to temperature was weakened, and the rubber was closer to a Newtonian fluid, with less extrusion swell phenomenon and no obvious spiral distortion. Compared with the dry mixing, the tensile strength, rebound rate, and abrasion resistance of the rubber composites prepared by this technology were increased by 11%, 31%, and 9%, respectively, providing theoretical and technical guidance for the green production and continuous production of high‐performance natural rubber composites. Highlights The process is achieved by a twin‐screw extruder and a twin‐rotor continuous mixer. The process promotes the formation of the filler‐rubber network. The sensitivity of viscosity to temperature is weakened, with no spiral distortion. The tensile strength, rebound rate, and abrasion resistance are increased by 11%, 31%, and 9%.