Technical Details of SK Conveying ElementStructural Geometry• Twin-start forward intermeshing thread profile with large pitch and deep screw channel design. The free volume increases by approximately 40% compared with conventional SE conveying elements. • The intermeshing thread profile enables mutual wiping between twin screws and delivers excellent self-cleaning performance. • The inner bore adopts involute spline to match the torque of the shaft for easy assembly, disassembly and interchangeability. • Model marking example: SK‑40/40: pitch 40 mm, element length 40 mm. Various pitch specifications are available. Large pitch focuses on feeding and conveying; small pitch is used for pre-pressure build-up conveying. Material Configuration• 38CrMoAlA nitrided steel: For general pellet compounding applications with high cost-performance. • WR5: For glass-fiber filled and high-wear working conditions. • WR13: Wear and corrosion resistance for battery powder and corrosive materials. • Nickel-base alloy: Applied for highly corrosive systems. Manufacturing Process• Integral forging and quenching & tempering heat treatment. • CNC grinding of thread profile with strict control of meshing clearance. • Smooth fillet transition at thread root to reduce material stagnation and adhesion. • Guarantee dimensional accuracy of outer diameter, pitch and spline. Process Parameter Characteristics• Shear level: Almost no shear • Conveying capacity: Strong forward conveying, mainly used for solid material transport • Shear heat: Extremely low, nearly no shear temperature rise • Mixing type: Barely any mixing, only for material conveying • Residence time: Short with low filling degree • Self-cleaning: Excellent, no material stagnant dead zones | Functions of SK Conveying Element•High-volume solid material conveying: Deep screw channel and large free volume improve feeding capacity, solving slipping, bridging and insufficient feeding issues of low-bulk-density powder and recycled materials, raising the upper limit of machine throughput. Mostly applied in main feeding section and downstream of side feeding. •Efficient material pushing and basic conveying flow establishment: Transport solid pellets and powder forward to the melting section. It generates no shear heat and prevents premature melting and slipping of materials during solid conveying. Matching SK elements of different pitches: large pitch for aggressive feeding; small-pitch SK moderately increases filling degree and builds pre-pressure forward. •Excellent self-cleaning to reduce material residue: Mutual wiping of twin-screw threads eliminates stagnant dead zones, suitable for frequent color change production without charred material residue. •Transition connection in screw configuration: As the basic conveying unit, it connects feeding section and melting section. It can also be placed between kneading blocks and mixing elements to dredge material flow and relieve pressure build-up as an isolating transition component. |
