Twin Screw Extruder Screw Elements, Screw Segments, Kneading Blocks and Kneading Disks

Conveying screw elements

Conveying screw elements move material forward with minimum shear. We produce single-flight, double-flight and triple-flight elements in pitches from 0.5D to 2D. The flight is ground on five-axis centres so the self-wiping geometry follows the OEM profile, which keeps the clearance to the barrel bore uniform along the whole screw.

• Pitch 0.5D, 1D, 1.5D and 2D
• Single, double and triple flight
• Right-hand and left-hand helix
• Through-hardened or surface-coated

Screw segments

A screw segment is the shaft-mounted building block of the screw set. Each segment is keyed to an involute spline shaft and stacked to the length you need. Because segments are individually replaceable, a worn mixing zone can be rebuilt without scrapping the whole screw shaft.

• Involute spline to DIN 5480
• Lengths in 1/4D increments
• Individually replaceable
• Matched to your existing shaft

Kneading block elements

Kneading blocks do the dispersive and distributive mixing. The stagger angle between adjacent disks sets the balance between conveying and mixing: 30 degrees conveys gently, 45 degrees is the general-purpose choice, 60 degrees raises shear, and 90 degrees gives maximum dispersive mixing with almost no conveying.

• 30, 45, 60 and 90 degree stagger
• Three to seven disks per block
• Neutral and left-hand conveying
• Bilobal and trilobal profile

Kneading disks

Single kneading disks are used where a short, intense shear gap is needed, typically at the end of a mixing block or in a degassing zone. Widths of 5 mm, 7 mm and 11 mm cover most ZSK and Berstorff geometries.

• Width 5, 7 and 11 mm
• Wide-angle and narrow-angle
• Bilobal and trilobal
• Hardness matched to the shaft

Twin-screw extruder screw element manufacturer

TMD Compounding manufactures screw elements in Nanjing, China, for compounders, masterbatch producers and machine builders worldwide. We hold tooling for the ZSK, Berstorff, Leistritz, JSW and Shibaura profiles and machine every element in-house: turning, five-axis grinding, heat treatment, coating and CMM inspection. Because we are a manufacturer rather than a stockist, we can supply a standard conveying element or a one-off element to your drawing.

• In-house machining, heat treatment and grinding
• Tooling for ZSK, Berstorff, Leistritz, JSW and Shibaura
• Standard elements made to OEM drawings
• One-off elements made to your drawing

Co-rotating screw element supply from China

Buyers looking for a co-rotating screw element supplier in China usually worry about two things: dimensional accuracy and delivery risk. We answer the first with a CMM report on every batch, and the second with a lead time confirmed in writing before the order. Elements ship from Nanjing by air or sea, with export packing and documents prepared for you.

• CMM report with every batch
• Lead time confirmed in writing
• Export packing and documentation
• Air or sea freight from Nanjing

Wear-resistant screw elements to OEM specification

Wear resistance is decided by three things: base steel, heat treatment and surface coating. We supply nitrided elements for unfilled polymers, PM-HIP tool steel at 58-62 HRC for glass-fibre and mineral-filled compounds, and PVD or HVOF tungsten-carbide coatings for the most abrasive duty. Every element is made to the OEM dimensional specification, so it can be mixed with original parts on the same shaft.

• Nitrided steel, 900-1100 HV
• PM-HIP steel, 58-62 HRC
• PVD TiN and TiAlN coatings
• HVOF tungsten carbide