Technical Details of Side‑Feeding LinerStructural Geometry• The inner bore adopts a twin‑screw figure‑eight intermeshing flow channel. The center‑to‑center distance of the two bores is strictly controlled to ensure uniform and proper working clearance between the screw and liner. • Closed liner: Fully enclosed figure‑eight inner bore without openings, suitable for closed barrel sections such as melting and homogenizing zones. • Open liner: A through process window is machined on the upper section, matching functional barrel sections for main feeding, side feeding, venting and vacuum devolatilization. • C‑type split liner: Two‑piece half‑split design for easy assembly and disassembly with low maintenance cost. The joint seam carries a slight risk of material accumulation. • Monolithic liner: Integrally formed figure‑eight bore with no joint seams, minimal stagnant dead zones and excellent anti‑adhesion performance, featuring higher machining precision and manufacturing cost. • The outer circle is interference‑fitted with the barrel housing, equipped with axial locating shoulders to eliminate axial shifting and circumferential rotation during operation. Material Configuration• 38CrMoAlA nitrided steel: For general compounding conditions, nitrided for hardening with outstanding cost‑performance. • WR5 powder alloy: Ultra‑high wear resistance for high‑wear applications including glass‑fiber filled and conventional high‑filling compounding. • WR13 powder alloy: Combined wear and corrosion resistance, applicable to battery slurry and corrosive material systems. • Nickel‑base alloy / Hastelloy: For severe highly corrosive working conditions such as fluoroplastics and reactive extrusion. Manufacturing Process• Forged blank with quenching and tempering heat treatment to guarantee substrate strength and toughness. • Precision CNC machining of the figure‑eight inner bore profile with strict control over center distance and geometric tolerance. • All edges of windows on open liners are smoothly rounded to eliminate sharp dead zones for material buildup. • Inner surface is hardened by nitriding or powder metallurgy HIP hot isostatic pressing for hard alloy forming. • Precisely controlled inner bore dimensions and unilateral clearance to ensure smooth screw rotation and cavity self‑cleaning performance. Process Parameter Characteristics• Maximum operating temperature: 350 °C • Assembly method: Interference press fit with barrel housing • Unilateral working clearance: 0.2‑0.4 mm (adjusted according to machine specifications) • C‑type split structure: Convenient assembly and low cost; slight risk of material accumulation at joint seams • Monolithic structure: No joint seams and strong anti‑buildup capability, suitable for heat‑sensitive materials and frequent color‑change production • Excellent thermal conductivity: Outer wall closely fits the inner barrel wall; heat can be rapidly transferred to barrel heating and cooling channels for precise temperature control | Functions of Side‑Feeding Liner•Wear and corrosion protection for barrel housing: Directly bears material erosion friction and chemical corrosion from melt. All wear loss is concentrated on the replaceable liner, preventing expensive barrel housing from scrapping and greatly reducing spare part and maintenance costs. •Form standard figure‑eight process flow channel: Precisely forms twin‑screw figure‑eight intermeshing inner cavity, regulates screw operating clearance and provides stable standard process environment for material conveying, pressure building, melting and mixing. •Differentiated structures adaptable to multiple process zones: Closed liners are used in closed melting and homogenizing sections to stabilize pressure; open liners reserve process windows to meet requirements for main feeding, side feeding, vacuum devolatilization and venting. •Reduce material stagnation and improve production stability: Monolithic seamless structure plus full rounded design greatly reduces adhesion, carbon deposition and char particle formation, suitable for heat‑sensitive materials and frequent color change across multiple formulations. C‑type split liners satisfy low‑cost production of general compounding. •Efficient heat exchange and precise temperature control: Relying on the fitted assembly structure, it quickly transfers material heat to barrel temperature control channels, realizing accurate heating and cooling in each process section and stabilizing |
