SJ25 Single Screw Extruder 

Compact, Precise, 360° Adjustable Lab-to-Production Solution

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Compact SJ25/26 single screw extruder with 0–3 kg/h output, 360° rotation and height-adjustable frame, optimized BM screw for high plastication and stable melt, premium electricals, and precise multi-zone temperature control—ideal for R&D, small-batch production, and profile/filament applications.

Product Overview

What is SJ25/26

The SJ25/26 is a high-precision single screw extruder designed for small-lot production, material testing, and laboratory-scale continuous extrusion. With a maximum output of 0–3 kg/h and a 26:1 L/D, it delivers uniform melting, excellent plastication, and stable throughput in a compact footprint.

360° Adjustable, Height-Lift Design

• 360° rotation and vertical lift for flexible line integration, easy alignment to downstream equipment, and ergonomic operation.
• Center height 1000 mm (+150, -50 mm) to accommodate different dies, calibration tables, and take-off heights.

Key Features

Optimized BM Screw Geometry

• High plastication rate and uniform melt quality ensure consistent product dimensions and smooth surfaces.
• Stable, continuous output supports precise diameter/thickness control for profiles, tubes, filaments, and sheets.

Durable Materials and Surface Treatment

• Screw and barrel made of 38CrMoAlA; screw surface hard chrome plated.
• Barrel inner surface is nitrided and finely honed for wear and corrosion resistance, extending service life with filled or abrasive materials.

Precise Temperature Control (5 Zones)

• Heating zones: Screw 3 zones, flange 1 zone, die 1 zone (total 5).
• Temperature range: 100–360 °C with Dongqi controllers (or customer-preferred instrumentation).
• Ceramic heater bands ensure fast, uniform heating for stable melt temperature.

Quality Electrical Components

• Stainless steel hopper for clean feeding.
• Delixi electricals, Schneider contactors and push buttons for reliability and global serviceability.

Reliable Drive and Gearbox

• 4 kW premium VFD motor, 50–1500 rpm wide speed range.
• Yaskawa 4 kW inverter for smooth vector control and precise torque at low speeds.
• Direct connection to a hardened-tooth gearbox (Ruidesen brand) for efficient power transmission and low noise.

Fast Changeover, Easy Integration

• Two-piece quick-open die flange with dual heater rods speeds up die changes and startup.
• Thermocouple and aviation connector models match customer samples for plug-and-play replacement.
• Custom exterior dimensions, styles, and screw fasteners strictly follow client-provided photos/drawings.

Technical Specifications

Extruder Model

• Model: SJ25/26
• Max Output: 0–3 kg/h
• Center Height: 1000 mm (+150, -50 mm)
• Frame: Height adjustable, 360° rotatable

Screw and Barrel

• L/D Ratio: 26:1
• Speed Ratio: 22:1
• Screw Rotation: Counterclockwise (viewed from shank to tip)
• Structure: Optimized BM screw for high plastication and uniform melt
• Materials: 38CrMoAlA; screw hard-chrome plated
• Barrel Treatment: Nitrided and honed inner surface
• Vent: Barrel with exhaust port
• Origin: In-house design, processed in Zhoushan
• QA: Supplier-issued material composition certificates

Heating and Control

• Zones: 5 total (3 screw, 1 flange, 1 die)
• Heating Method: Ceramic heater bands
• Heating Power: 1 kW × 3 (core band groups), auxiliary die heaters included
• Temperature Range: 100–360 °C
• Controllers: Dongqi (or as per customer’s current model preference)

Drive and Transmission

• Main Motor: 4 kW branded VFD motor
• Speed Range: 50–1500 rpm
• Speed Control: 4 kW Yaskawa variable-frequency drive
• Connection: Direct-coupled motor-to-gearbox
• Gearbox: Hardened-tooth reducer (Ruidesen)

Die and Interfaces

• Die Flange: Two-piece quick-open type with two heater rods
• Sensors/Connectors: Thermocouples and aviation plugs per customer samples

Build and Customization

• Exterior dimensions and style per customer photos
• Screw/bolt sizes strictly matched to provided references

Process Advantages

Stable Melt, Clean Surface

• Optimized screw ensures low pulsation, excellent mixing, and minimal gels for premium surface quality.

Wide Material Window

• Suitable for PP, PE, ABS, PC, PMMA, PETG, TPU/TPE, PA, and additive-rich formulations for R&D and specialty runs.

Fine Speed and Temperature Control

• Broad RPM range and precise multi-zone heating enable accurate residence time and viscosity tuning for lab-to-pilot transferability.

Applications

R&D and Quality Labs

• Material formulation screening, color masterbatch evaluation, additive and filler trials, rheology tuning, and sample preparation.

Small-Batch Production

• Precision profiles, filaments, micro-tubing, wire/cable insulation samples, and thin sheets for pilot orders.

Education and Demonstration

• Universities and institutes for process education, extrusion training, and demonstration lines.

User Feedback and Market Recognition

What Customers Say

• “The 360° rotation and center-height lift make alignment with different dies and take-off units effortless.”
• “Uniform melt and stable output greatly improved consistency for our micro-tube line.”
• “Yaskawa VFD and hardened gearbox ensure smooth startup and tight low-speed control for R&D.”

Market Performance

• Adopted by labs, universities, and specialty processors for reliable small-lot, high-precision extrusion.
• Strong repeat orders due to durability, ease of setup, and compatibility with existing downstream equipment.