Technical Details of Mixing ElementStructural Geometry• Continuous smooth S-curved rotor profile, without angular staggered discs like KB kneading blocks. • Large flow channel volume. Materials are kneaded, stretched and subjected to moderate shear between curved surfaces. • Twin screws intermesh and wipe each other to achieve self-cleaning effect. • It delivers weak positive pumping capacity and will not fully block material flow. • The inner bore adopts involute spline. Used in groups and can be matched with front and rear transition elements. Material Configuration• 38CrMoAlA nitrided steel: For general compounding applications. • WR5: For high-wear conditions with glass fiber and mineral high filling. • WR13: Wear and corrosion resistance for battery materials and corrosive melts. • Nickel-base alloy: For highly corrosive reactive extrusion. Manufacturing Process• Integral forging and quenching & tempering heat treatment. • 5-axis CNC milling of smooth S-shaped curved surfaces with no sharp corners. • Strictly control meshing clearance to ensure mutual wiping self-cleaning of twin screws. • Large fillet at root to reduce risk of material adhesion and accumulation. Process Parameter Characteristics• Shear level: Medium shear, lower than KB kneading blocks • Conveying capacity: Weak forward conveying, no severe pressure build-up • Shear heat: Medium to low, remarkably lower than KB kneading block sets with equivalent mixing performance • Mixing type: Balanced dispersive mixing and distributive mixing • Residence time: Moderately prolonged with narrow residence time distribution and few dead zones • Self-cleaning: Excellent, suitable for frequent color changeover | Functions of Mixing Element•Gentle kneading by kneading and stretching, balancing dispersion and distribution. The S-curved rotor kneads, stretches and applies moderate shear to materials. It can break mild agglomerates of fillers and color pigments and realize uniform distribution of melt composition and temperature. Compared with KB, it avoids excessive molecular chain scission and severe glass fiber breakage caused by sharp-edge shearing. • Reduce shear heat and protect heat-sensitive materials. It achieves equivalent mixing with lower melt temperature rise, restraining degradation and yellowing of heat-sensitive polymers. Suitable for highly sensitive formulations such as PLA, TPE, partial degradable plastics and elastomers. • Good self-cleaning to shorten color change and purging time. Continuous smooth curved surface plus twin-screw intermeshing wiping prevents material stagnation and accumulation and reduces char particles and black specks. Suitable for multi-grade and frequent color change production. • Inherent weak conveying reduces risk of blockage and pressure build-up. Unlike KB kneading blocks with nearly no conveying capacity, the mixing element has forward conveying capability to maintain continuous material flow and minimize dead zone blockage. It can be directly connected in screw configuration; better performance when combined with transition elements on both sides. • Suitable for high filling and reactive extrusion processes. Large free volume accommodates high-content powder fillers. It renews melt interface continuously, suitable for reactive extrusion and promotes sufficient chemical reaction. |
