Armfield FT28 Continuous Screw Oil Expeller

Overview

The Armfield FT28 Continuous Screw Oil Expeller is a precision-engineered, benchtop-scale screw press designed for controlled, continuous mechanical extraction of edible oils from oil-rich seeds and kernels. Operating on the principle of progressive compression within a tapered barrel, the FT28 utilizes a single rotating screw to convey, compact, and shear feedstock—generating sufficient internal pressure (up to ~60 bar) to rupture oil cells and separate oil from solid cake. Unlike batch expellers or solvent-based systems, the FT28 delivers solvent-free, low-temperature extraction (< 60 °C), preserving thermolabile compounds such as tocopherols, phytosterols, and natural antioxidants. Its 28 mm screw diameter and variable-speed drive (0–60 rpm) enable systematic process parameter studies—including residence time, compression ratio, and throughput—making it ideal for formulation development, process optimization, and small-batch pilot production in food science laboratories, R&D centers, and academic institutions.

Key Features

• Stainless steel (AISI 304) wetted components ensure full compliance with food-grade material requirements and resistance to corrosion from organic acids and residual oils.
• Variable-frequency motor drive enables precise control of screw rotation speed, facilitating reproducible studies of shear rate and mechanical energy input.
• Modular barrel design with interchangeable compression zones allows empirical evaluation of screw geometry effects on oil yield, cake residual oil content, and paste rheology.
• Integrated feed hopper (2 L capacity) with adjustable feed rate gate supports consistent solids introduction and minimizes bridging or channeling.
• Self-cleaning screw profile and tapered die assembly reduce maintenance frequency and support rapid changeover between different seed types (e.g., sunflower, rapeseed, sesame, flax).
• Compact footprint (450 × 320 × 680 mm) and low power consumption (0.37 kW) make it suitable for standard laboratory electrical infrastructure without dedicated ventilation or cooling.

Sample Compatibility & Compliance

The FT28 accommodates whole, cracked, or flaked oilseeds with particle sizes ranging from 0.5 to 8 mm—provided moisture content is maintained between 6–12% (w.b.) for optimal oil release and cake formation. It has been validated for use with common feedstocks including soybean, peanut, canola, safflower, and moringa oleifera seeds. All structural and operational aspects conform to CE Machinery Directive 2006/42/EC. The stainless steel construction meets EC No. 1935/2004 requirements for materials intended to come into contact with food. While not certified for industrial-scale GMP manufacturing, the FT28 supports GLP-aligned experimental protocols and generates traceable process data suitable for regulatory filing in early-stage product development.

Software & Data Management

The FT28 operates as a standalone mechanical system with analog speed indication and manual torque observation; it does not include embedded digital control or data logging hardware. However, its standardized electrical interface (230 V AC, 50 Hz) permits integration with external instrumentation—such as load cells, inline flow meters, or thermal sensors—via third-party DAQ systems (e.g., National Instruments or LabVIEW-compatible platforms). Users routinely couple the expeller with gravimetric oil collection, digital cake moisture analyzers, and GC-FID for fatty acid profiling—enabling full mass balance closure and yield validation per ASTM D6751 (biodiesel feedstock) or ISO 660 (animal and vegetable fats and oils — determination of acid value and acidity).

Applications

• Optimization of pre-treatment parameters (conditioning temperature, moisture, flaking thickness) prior to full-scale pressing.
• Comparative assessment of oil recovery efficiency across cultivars, harvest years, or storage conditions.
• Development of cold-pressed specialty oils for functional food and nutraceutical markets.
• Teaching unit for unit operations courses covering solid-liquid separation, extrusion mechanics, and food process engineering.
• Feasibility screening for decentralized oil production in low-infrastructure settings, leveraging its robust mechanical architecture and minimal utility requirements.

FAQ

Is the FT28 suitable for extracting oil from high-fiber or high-mucilage seeds (e.g., chia or basil)?

Yes, but pre-processing (e.g., dry heating or partial defatting) may be required to reduce gum formation and prevent die clogging. Empirical trials are recommended to establish optimal moisture and temperature windows.
Can the residual cake be used directly as animal feed?

The cake retains protein and fiber integrity and is commonly evaluated for ruminant feed applications; however, final suitability depends on local regulatory limits for residual solvent (not applicable here) and mycotoxin levels in raw seed.
Does Armfield provide calibration documentation or validation protocols?

Armfield supplies a Factory Acceptance Test (FAT) report confirming mechanical performance against nominal specifications. Process-specific validation (e.g., yield repeatability across operators) must be conducted by the end user per ISO/IEC 17025 guidelines.
What maintenance intervals are recommended for routine operation?

Lubrication of the gearmotor every 500 operating hours and visual inspection of screw wear and die clearance every 100 kg of processed material are advised. Spare parts—including screw segments, die plates, and feed inserts—are available directly from Armfield UK.