Low-Load High-Efficiency Dispersed Screw for Halogen-Free Low-Smoke Cable Material in High-Speed Extrusion

This study aims to solve the contradiction of "high viscosity low thermal stability" in the processing of high filled flame retardant system, and improve the processing efficiency and product quality of halogen-free cable material. To this end, the research team successfully developed a new type of segmented variable parameter screw, and systematically improved the processing technology through the triple innovative technical means of thread topology optimization, dynamic thermal management and low shear mixing. Firstly, the flow channel distribution and shear characteristics of the screw were improved by thread topology optimization design to reduce the viscosity gradient in the melting process; Secondly, the dynamic thermal management technology was used to optimize the heating and cooling system and improve the thermal stability of the material; Finally, through the low shear mixing design, the shear stress of the material in the processing process is significantly reduced, and the material performance degradation caused by excessive mixing is avoided. The results showed that the extrusion amount of halogen-free cable compound increased significantly by 58.8% to 350kg/h at 1350rpm, the smoke density decreased significantly by 60% , dropping to 48%, and the energy consumption decreased effectively by 27.1%. These data fully verified the excellent performance of the new screw in improving production efficiency, improving material properties and reducing energy consumption. This research achievement has solved the technical bottleneck in the processing of high filled flame retardant system, and provided innovative solutions for the high-efficiency, low energy consumption and high-quality processing of halogen-free cable materials, which has important theoretical significance and practical application value.