The SLG35 laboratory double‑screw food main machine is developed based on mature double‑screw extrusion technology combined with years‑long R&D experience in extruded‑food processes. It is suitable for university teaching, scientific‑research experiments and new‑product formula development.

The screws of the equipment feature self‑cleaning performance and high material‑conveying efficiency, achieving favorable material shearing and homogenizing effects. Equipped with variable‑frequency speed‑regulating system and centralized integrated control, the main machine delivers convenient operation and precise adjustment. It adopts co‑rotating fully‑intermeshing trapezoidal‑helix double‑screw structure to meet the requirements of small‑batch formula tests.

The complete machine has compact footprint and complete functions with easy installation. It possesses all processing functions of conventional double‑screw equipment to satisfy multi‑scenario teaching and scientific‑research test requirements. It can be used for trial production of various food formulas. Applying this machine at the new‑product R&D stage can reduce raw‑material loss caused by trial runs on large‑scale production lines.

Equipment Structure

①Material‑storage barrel ②Feeding device ③Distribution box ④Drive unit ⑤Extrusion chamber ⑥Cooling device ⑦Rotary‑cutting device ⑧Lubrication device ⑨Control panel

As shown in the figure, the SLG35‑A main machine is mainly composed of nine components. The prepared raw materials are fed into ①material‑storage barrel and conveyed to ⑤extrusion chamber by ②feeding device. The extrusion chamber is equipped with heating unit and ⑥cooling device to adjust the temperature required for raw‑material processing. The screws inside the extrusion chamber are driven jointly by ④drive unit and ③distribution box. As a core component, the distribution box is forcibly lubricated by ⑧lubrication device to ensure continuous equipment operation. Raw materials are mixed and kneaded within the extrusion chamber, extruded through a special die under high‑temperature and high‑pressure conditions to form extruded semi‑finished products, and finally cut into finished products by ⑦rotary‑cutting device.

All power of this equipment is centrally controlled by ⑨control panel for easy operation.

(1) Automatic Feeding MechanismThis mechanism consists of screw, material bin, stirring blades, frame, motor and other parts. It is installed above the machine distribution box and adopts screw conveying with adjustable conveying speed.

(2) Extrusion Main MachineThe equipment comprises six units: extrusion system, lubrication system, thrust mechanism, transmission system, heating system and cooling system.

The double‑screw extrusion system is fitted with two co‑rotating intermeshing screws of left‑hand structure. During operation, they scrape off materials adhered to screw surfaces and convey materials forward. The screws adopt sectional combined structure with pitches of 28 mm, 22 mm, 16 mm and 14 mm in sequence, and the pitch of the end‑section screw is 16 mm. Five semicircular grooves are evenly distributed along the axial direction, and trapezoidal threads with thread depth of 5.5 mm are applied. Heating and cooling assemblies are mounted outside the extrusion chamber to regulate material processing temperature. When materials pass through the final‑section screw, they are fully subjected to shearing action, accumulate internal energy and realize extrusion expansion.

The lubrication system includes gear pump, oil tank and oil circuit, which provides forced lubrication and cooling for rotating components inside the distribution box.

The transmission system is equipped with customized MTD77 helical‑gear hard‑tooth‑surface reducer with transmission ratio 1:9.25, directly coupled with 5.5 kW ABB motor. Power is transmitted to the distribution box to drive the two output shafts for co‑rotating operation. External meshing of helical gears Z18 and Z42 forms a triangular transmission structure. Two sets of Z18 helical gears bear torque and radial thrust transmitted by the screws respectively. The whole machine adopts variable‑frequency speed‑regulation solution with wide adjustment range and stable operation. Tandem thrust cylindrical roller bearing sets (Model M4CT1242) are fitted on gear shafts inside the box to support stable equipment operation.

The heating and cooling systems work in coordination with a cooling tower. Heating consists of three independent temperature‑control zones, each equipped with 0.5 kW infrared stainless‑steel heating ring, total heating power 1.5 kW; temperature of each zone can be set independently. Cooling zones correspond one‑to‑one with heating zones. Solenoid valves automatically adjust water circulation according to temperature signals to maintain temperature balance.

(3) Rotary‑cutting DeviceComposed of motor, cutter holder and linear guide rail. The cutter holder is fixed on the die body. The motor moves back and forth along the linear guide rail to flexibly adjust the gap between cutter and die. Driven by the motor, the cutter rotates to cut products of target length.

(4) Control SectionEach system of SLG35‑A main machine is centrally managed by the control panel for convenient operation and stable performance. The equipment is equipped with multiple automatic protection devices and working‑condition display instruments.

Screw Diameter: Φ35 mmScrew Rotation Speed: 0～380 rpmProcessing Capacity: 10～30 kg/hTemperature‑control Range: 0～200 ℃Heating Power: 1.5 kWHeating Zones: 3Cooling Zones: 3Speed‑regulation Mode: Variable‑frequency Speed RegulationMain‑drive Power: 5.5 kWOil‑pump Power: 0.18 kWMachine Center Height: 1000 mmOverall Dimension: 2500×700×1600 mm