At present, carbon black masterbatches occupy a core position in the commodity structure of color masterbatches for nylon 6 fibers in China, but the domestic carbon black masterbatches are mainly imported. The reason is that the carbon black powder does not have excellent dispersion in carrier resin under the premise of high blackness of masterbatches, resulting in the fact that few domestic masterbatch manufacturers can stably provide carbon black masterbatches. However, imported carbon black masterbatches are expensive, which leads to the high production cost of black nylon 6 filament fibers for civil use and low market competitiveness. In addition, the imported carbon black masterbatches generally have the problem of short spinning component cycle, which is not conducive to continuous spinning production and affects the production efficiency. In order to break the high dependence of carbon black masterbatches for nylon 6 fibers on imports, the author independently researched a complete set of carbon black masterbatch production and spinning integration process through production experiment and exploration. The carbon black masterbatches were synthesized by using the co-rotating parallel twin-screw extrusion method through the following processes: melting plasticization behavior, screw shearing, water-cooled dicing, vibration screening, vacuum drying and other procedures. The polyamide 6 bright chips (64wt%), nano-grade carbon black powders (30wt%) and composite carbon black super-dispersant powders (6wt%) were employed as starting materials in the synthetic strategy. In order to further improve the quality of carbon black masterbatches, experiments were carried out on different nylon 6 chips, different proportions of carbon black powders and super-dispersant powders in the masterbatches, different initial temperatures of side feed of the extruder and different die temperatures of the twin-screw extruder. According to the production process of carbon black masterbatches and the actual use of spinning conditions, the author selected the bright chips as the base material of carbon black masterbatches for the final masterbatch production process, with the ratio of carbon black powders and super-dispersant being 30:6, the initial temperature of the side feed of the extruder being 85 °C, and the die temperature of the twin screw extruder being 230 °C. The relative viscosity, melting point, moisture content and melt index of the carbon black masterbatch was 1.94, 223 °C, 0.048 8% and 10.6 g/10min, respectively. In order to clarify the spinning performance of the carbon black masterbatch which was used as the dope dyeing colorant, the carbon black masterbatch was used in the continuous production of dope dyed black nylon 6 filament fibers for civil use (high-oriented yarn, 49.95 dtex/12F) at an added ratio of 4.7wt%. In order to further improve the quality of black nylon 6 filament fibers for civil use, experiments were carried out by selecting different spinning component types, different spinneret surface temperatures, different spinning component starting pressures and different component apertures. By comparing the spinning conditions and component cycle, black nylon 6 filament fibers for civil use were produced by using single-cavity double spinneret assembly, with the spinneret surface temperature of 235 °C, spinning assembly initial pressure of 16.2 MPa and assembly aperture of 0.26 mm. The result clearly shows that the service life of the spinning component can be up to 18 days, the daily average boost pressure of the spinning component is about 0.21 MPa, the daily average broken yarn is about 4.7 times, the daily average floated yarn is about 2.6 times, the breaking strength of the fiber is 3.38 cN/dtex, the breaking elongation ratio of the fiber is 80.96%, the unevenness of the fiber is 0.61%, the oil ratio of the fiber is 1.24%, the boiling water shrinkage of the fiber is 7.66%, and the network density of the fiber is 12 dots per meter. At present, there is still room for improvement in the production process of self-produced carbon black masterbatches, for example, whether it is possible to develop a single-type dispersant instead of a composite-type dispersant, and whether the filtration process can be optimized in the masterbatch production process to further enhance the carbon black masterbatch in the spinning process of continuous use of the spinning module cycle, and reduce the rate of the daily floated yarn and the daily average broken yarn and so on. In the future, our team will continue to devote to the research of carbon black masterbatches for nylon 6 fibers and the improvement of their spinning performance to help the industry to implement “the carbon peaking and carbon neutrality” action. [ABSTRACT FROM AUTHOR]