IKA RW 28 digital Overhead Stirrer

Overview

The IKA RW 28 digital is a high-performance overhead stirrer engineered for precision mixing and dispersion tasks in research laboratories, quality control environments, and pilot-scale production settings. Designed around a robust cast-aluminum and thermoplastic polymer housing, the unit employs a high-efficiency DC motor with constant-torque transmission architecture to maintain consistent rotational energy across its full speed range — critical when processing non-Newtonian or shear-thinning fluids. Its core operating principle relies on mechanical torque transfer via a hollow stainless-steel stirring shaft (10.5 mm internal diameter), enabling compatibility with both standard clamped impellers and specialized geometries such as anchor, paddle, or helical blades. Unlike magnetic stirrers, the RW 28 digital delivers scalable mechanical agitation suitable for volumes up to 80 L of aqueous media and viscosities up to 50,000 mPa·s — making it particularly suited for polymer synthesis, suspension formulation, emulsion preparation, and catalyst slurry homogenization.

Key Features

• Two selectable speed ranges: Range I (60–400 rpm at 50 Hz) for high-torque, low-speed applications; Range II (240–1400 rpm at 50 Hz) for rapid dispersion and low-viscosity blending
• LED digital speed display with ±1 rpm setting resolution and ±10 rpm measurement tolerance — calibrated per IKA’s internal traceable metrology protocol
• Overload protection with error-code feedback (e.g., E1 = motor overheating, E2 = shaft jam) and automatic thermal cutoff via integrated temperature limiter
• Ergonomic, low-noise design delivering ≤62.5 dB(A) under no-load conditions — optimized for continuous operation in shared laboratory spaces
• Hollow shaft configuration supports insertion of temperature probes or pH electrodes during active stirring without interrupting process continuity
• IP 40 ingress protection rating ensures resistance against solid objects ≥1 mm and limited dust exposure — appropriate for general-purpose lab use under controlled environmental conditions (5–40 °C, ≤80 % RH)
• Universal voltage compatibility (100–240 V, 50/60 Hz) with CE, RoHS, and DIN EN 60529 certification for global deployment

Sample Compatibility & Compliance

The RW 28 digital accommodates a broad spectrum of sample types — from low-viscosity solvents and aqueous buffers to highly viscous pastes, gels, and heterogeneous suspensions. Its dual-range torque profile allows seamless transition between viscous anchoring (e.g., silicone elastomer compounding) and high-shear dispersion (e.g., pigment deagglomeration in coatings). The 1–10 mm chuck accepts standard ISO 8573-compliant stirring rods and custom-fabricated impellers. While the device itself does not incorporate temperature regulation, it is routinely deployed in conjunction with jacketed reactors and external circulators compliant with ASTM E2912 and ISO 17025 workflows. Its mechanical construction and electrical safety design conform to IEC 61010-1 for laboratory equipment, supporting integration into GLP- and GMP-aligned validation protocols where audit trails and operational consistency are required.

Software & Data Management

As a standalone electromechanical instrument, the RW 28 digital operates without embedded firmware or network connectivity. All operational parameters — including real-time speed, overload status, and thermal alerts — are communicated via front-panel LED indicators and discrete error codes. For laboratories requiring documentation compliance under FDA 21 CFR Part 11 or ISO/IEC 17025, users may integrate the unit with external data loggers or PLC-based supervisory systems via analog tachometer output (0–10 V) or optional digital interface modules (sold separately). IKA provides calibration certificates traceable to national standards upon request, and maintenance logs — including motor service intervals and torque verification records — support long-term equipment qualification in regulated environments.

Applications

• Preparation of pharmaceutical suspensions and ointment bases under USP & Ph. Eur. compendial methods
• Homogenization of battery electrode slurries prior to coating and drying cycles
• Controlled addition and dispersion of nanomaterials in polymer matrices for composite R&D
• Batch-wise synthesis of polymeric resins and crosslinked hydrogels
• Stirring of fermentation broths and bioreactor seed cultures in microbiology labs
• Standardized mixing of reference standards for viscosity calibration (e.g., against Cannon-Fenske or rotational viscometers)

FAQ

Is the RW 28 digital compatible with explosion-proof environments?

No — it lacks ATEX or IECEx certification and is not rated for use in hazardous locations.
Can the unit be mounted on third-party reactor stands?

Yes — its 16 mm diameter extension arm and standardized M12 mounting thread enable secure attachment to most ISO-compliant lab frame systems.
Does IKA provide IQ/OQ documentation for this model?

Yes — installation and operational qualification templates are available upon request and may be customized to site-specific SOPs.
What maintenance intervals are recommended for continuous operation?

Motor brush inspection every 2,000 hours; gear train lubrication every 5,000 hours; annual torque verification using certified load cells.
Is the hollow shaft compatible with all IKA impeller types?

It accepts all IKA-standard clamping impellers with shank diameters between 1–10 mm; however, certain high-aspect-ratio dispersers require optional reinforced shaft adapters.