Technical Details of Transition ElementStructural Geometry• The channel depth, lead and thread start number change smoothly along the axial direction. One end matches the flow cross-section of upstream element and the other end matches downstream element, eliminating butt steps. • SKN: The inlet side retains the deep screw channel of SK, while the outlet side gradually reduces channel depth for smooth transition to standard SE conveying threads. • Start-number transition element: Realizes smooth thread conversion between single-start ↔ twin-start and twin-start ↔ triple-start. • Mixing element transition block: Used for transition between conveying threads and ZME/TME toothed disc elements to smooth the change of flow channel cross-section. • The inner bore adopts involute spline. Assembled in pairs to ensure intermeshing self-cleaning. Large fillet at thread root reduces the risk of material adhesion. Material Configuration• 38CrMoAlA nitrided steel: For general compounding applications. • WR5: For glass fiber and high-wear filling conditions. • WR13: Wear and corrosion resistance for battery powder and corrosive materials. • Nickel-base alloy: Used for highly corrosive working conditions. Manufacturing Process• Integral forging and quenching & tempering heat treatment. • CNC milling of gradual thread profile to ensure continuous and smooth axial cross-section without abrupt steps. • Strictly control meshing clearance to guarantee mutual wiping self-cleaning of twin screws. Process Parameter Characteristics• Shear level: Low shear • Conveying capacity: Forward conveying to keep material moving forward • Shear heat: Low, barely adding extra temperature rise • Mixing type: Weak distributive mixing, no strong dispersive effect • Self-cleaning: Excellent, eliminates dead zones at joints • Residence time: No substantial extension of residence time | Functions of Transition Element•Eliminate butt steps and prevent material stagnation and accumulation. Elements with different channel depths or different thread start numbers cannot be directly connected, which will form stepped dead zones prone to material retention, degradation and char particles. Transition elements smoothly change the flow cross-section and remove stagnant dead zones, improving production stability for heat-sensitive materials and frequent color-change formulations. • Gentle material compression and reduced local pressure build-up. When transitioning from large-volume deep-channel elements to shallow-channel elements, materials are compressed gradually with mild pressure gradient. Instant pressure shock is avoided, screw torque fluctuation decreases and operation becomes more stable. Typical application: SK deep-channel feeding section → SKN transition → SE standard conveying element. • Maintain forward material conveying. It retains forward pushing capability without blocking material flow or causing clogging while realizing flow channel geometry switching. | 
