Technical Details of SMEStructural GeometryThe base body adopts forward conveying threads. Multiple shallow recirculation and distribution grooves are cut circumferentially on the screw flight, and the grooves connect adjacent screw channels. While materials are conveyed forward, controlled local recirculation is generated without forming severe stagnant dead zones. It features fully intermeshing geometry; mutual wiping between twin screws achieves self-cleaning effect. The inner bore is designed with involute spline for convenient interchangeable assembly and disassembly. Material Configuration• 38CrMoAlA nitrided steel: General compounding applications with high cost-performance. • WR5: For general wear-resistant working conditions. • WR13: Combined wear and corrosion resistance, suitable for battery slurry and corrosive systems. • Nickel-base alloy: Used for highly corrosive service conditions. Manufacturing ProcessIntegral forging and heat treatment, followed by CNC grinding to guarantee dimensional accuracy of outer circle, screw flights and distribution grooves. The meshing clearance is controllable, and the edges of grooves are smoothly rounded to reduce material adhesion and accumulation on walls. Process Parameter Characteristics• Shear level: Low shear • Conveying capacity: Positive conveying available. Compared with conventional SK conveying elements, its conveying and pressure-building capacity is slightly reduced. • Shear heat: Very low, leading to low overall machine energy consumption. • Mixing type: Strong distributive mixing, weak dispersive mixing. • Residence time: Slightly prolonged locally with relatively wide residence time distribution. • Self-cleaning performance: Excellent, superior to TME toothed disc elements. | Functions of SME•Forward material conveying: Retains basic forward pushing capacity. Unlike TME disc elements which have nearly no conveying capability, it ensures material throughput and output. When connected in series in the screw sequence, it will not cause severe pressure build-up or material blockage. •Enhanced axial distribution homogenization: The distribution grooves enable melt exchange between different screw channels and realize flow splitting and recombining. It improves distribution uniformity of temperature, additives, color pigments and fillers. Suitable for uniform dispersion of additives and color masterbatches, eliminating local melt temperature difference and composition fluctuation. • Low heat generation to protect heat-sensitive materials: Gentle shearing action with low shear heat output suppresses overheating degradation and yellowing of melt. It is applicable to PVC, TPU, biodegradable plastics and long glass fiber modification, protecting fiber length from damage to the maximum extent. • Homogenizing transition between kneading block groups: Installed before, after or between KB kneading block sets, it breaks up local melt inhomogeneity generated by kneading blocks, smooths pressure and temperature gradients and improves overall melt quality. •Improve preconditions for venting and devolatilization: Placed upstream of the devolatilization section to fully renew melt surface and raise removal efficiency of volatile substances. |
