Custom SJ35 Extruder Manufacturer & High-Precision Extrusion Lines

The SJ35 represents the optimal engineering balance for precision extrusion: an SJ25 often lacks sufficient melt reservoir pressure and plasticizing output (typically capped under 5-8 kg/h) when extruding medium-wall tubes or high-viscosity resins at elevated line speeds. Conversely, an SJ45 contains excessive barrel hold-up volume, resulting in extended residence time that induces polymer degradation, yellowing, or molecular breakdown in heat-sensitive resins like soft PVC, PUR, and fluoropolymers. The custom SJ35 provides an ideal plasticizing range of 2 to 28 kg/h, yielding steady, laminar melt delivery with minimal material residency.

Yes. Custom SJ35 extruders are engineered with flexible height-adjustable and tilt-adjustable support carriages, allowing seamless physical coupling with primary extrusion lines (such as SJ65, SJ75, or SJ90 systems). Control integration is achieved via standardized industrial communication protocols including Profinet, Ethernet/IP, and Modbus TCP. This enables the central line PLC to slave-sync the SJ35's screw speed, synchronize line start/stop sequences, and log melt temperature and pressure curves within a single unified SCADA interface.

We eliminate melt pressure pulsation through a tri-layer engineering approach: First, a high-precision barrier screw with an integrated distributive mixing head stabilizes the melt pool before discharge. Second, our drive train utilizes direct-coupled permanent magnet synchronous servo motors featuring closed-loop encoder feedback with a velocity jitter rating below ±0.01 RPM. Third, high-frequency Dynisco/Gefran melt pressure transducers monitor pressures in the adapter zone, dynamically modulating motor output to maintain die pressure stability within ±0.25 bar.

When processing fluorinated or halogenated polymers, thermal shearing releases highly corrosive hydrogen fluoride (HF) off-gases. For these specialized SJ35 builds, standard nitrided 38CrMoAlA steel is strictly avoided. Instead, we fabricate the entire screw and barrel assembly using high-nickel cobalt-chromium superalloys such as Hastelloy C-276, Inconel 625, or proprietary nickel-base bimetallic linings (e.g., Colmonoy or Xaloy 306/800). The die head, crosshead pin, and sizing bushes undergo identical superalloy treatments or high-purity electro-less nickel micro-coatings.

On our dedicated cleanroom-grade precision medical tube lines powered by the custom SJ35 extruder, our customers reliably manufacture micro-tubes down to 0.35 mm outer diameter (OD) with wall thicknesses down to 0.05 mm. When integrated with our multi-axis high-speed laser measurement gauge, automated vacuum calibration water tank, and servo crawler puller, the line maintains outer diameter tolerances within ±0.01 mm (and down to ±0.005 mm under controlled cleanroom ambient temperatures) with CPK values consistently exceeding 1.67.

The downstream sizing tank utilizes an electronic proportional vacuum regulating system coupled with closed-loop water level and water temperature controls (±0.5°C). As line speed accelerates or decelerates, the system automatically adjusts vacuum levels inside the first cooling chamber. This prevents tube collapse during high-speed take-up or ovality distortion caused by excessive drag at lower velocities, ensuring perfectly round cross-sections across all production batches.

Every custom SJ35 line undergoes comprehensive FAT at our Haian manufacturing plant. We invite clients or third-party inspection agencies to witness trial production using the client's actual specified resin pellets. During the trial, we document continuous 4-to-8 hour running data, including temperature stability, motor thermal curves, melt pressure variance, laser-measured outer diameter consistency, wall concentricity, line speed limits, emergency stop safety interlocks, and cut-length precision. Equipment is only cleared for crating upon client sign-off on the formal FAT verification protocol.