Mary Ann® SS-25 Rotary Sieve with Stackable Screening Columns

Overview

The Mary Ann® SS-25 Rotary Sieve is a precision-engineered, benchtop dry-sieving instrument designed for standardized particle size distribution analysis in quality control, R&D, and regulatory-compliant laboratories. Operating on the principle of combined rotational motion and controlled tapping—per ASTM E11, ISO 3310-1, and USP <786>—the SS-25 delivers reproducible, operator-independent separation across a broad particle size range (4.75 mm to 20 µm, corresponding to sieve numbers #4–#635). Its patented tilting-angle mechanism (45° inclination) enhances material fluidization and stratification during rotation, while the cast-aluminum hammer assembly—finished with durable hardwood veneer—delivers consistent kinetic energy transfer without mechanical wear or resonance-induced variability. Unlike vibratory or sonic sievers, the SS-25 employs deterministic mechanical agitation optimized for cohesive, fibrous, or moderately abrasive powders, making it especially suitable for pharmaceutical excipients, metal powders, catalysts, ceramics, and food-grade granules.

Key Features

• Stackable screening column architecture supporting up to 26 in (660 mm) total height—enabling multi-stage fractionation without clamping or alignment tools
• Dual voltage compatibility: SS-25 (115 V / 60 Hz) for North American labs; SS-25F (220 V / 50 Hz) for EU/Asia deployments
• Precision digital timer with ±1-second accuracy and 1–99 minute programmable duration, compliant with GLP audit-trail requirements
• Modular support frame functions both as structural base and dedicated storage rack for nested test sieves
• Reversible hinged cabinet door—installable on left or right side—to accommodate lab layout constraints and safety egress pathways
• Standardized sieve compatibility: accepts 8 in (203 mm) and 12 in (305 mm) diameter ASTM E11 / ISO 3310-1 test sieves in stainless steel, brass, or nylon mesh configurations
• Robust cast-aluminum housing with vibration-dampening feet and sealed motor compartment for long-term operational stability

Sample Compatibility & Compliance

The SS-25 accommodates free-flowing to marginally cohesive dry particulates, including but not limited to API powders, lactose blends, ground spices, polymer resins, and sintered metal feedstocks. It is explicitly validated for use with certified reference sieves traceable to NIST standards. The system meets mechanical performance criteria outlined in ASTM D6913 (soil particle analysis), ISO 13320 (laser diffraction correlation), and FDA guidance for powder characterization in solid dosage form development. All timing, tilt angle, and rotational speed parameters are factory-calibrated and documented per IQ/OQ protocols—supporting 21 CFR Part 11–ready software integration when paired with optional data logging modules.

Software & Data Management

While the SS-25 operates as a standalone electromechanical instrument, its timer output signal (TTL-compatible) enables synchronization with external data acquisition systems (e.g., LabVIEW, MATLAB, or LIMS platforms) for timestamped sieve residue logging. Optional RS-232 or USB-to-serial adapters facilitate automated cycle reporting, batch ID tagging, and electronic record retention aligned with ALCOA+ principles. Audit trails—including start/stop timestamps, operator ID input fields (via connected terminal), and calibration event logs—can be exported in CSV or PDF format for internal review or regulatory submission.

Applications

• Pharmaceutical: Granule uniformity testing per USP <786>; blend homogeneity assessment prior to compression
• Materials Science: Particle size specification verification for additive manufacturing feedstock powders (e.g., Ti-6Al-4V, Inconel 718)
• Food & Agriculture: Flour fineness grading (ASTM D4298); spice particle distribution profiling
• Geotechnical Engineering: Soil gradation analysis per AASHTO T 27 and ASTM D6913
• Quality Assurance: Incoming raw material inspection against supplier-certified PSD specifications
• Research: Method development for wet/dry sieving correlation studies and sieve wear monitoring programs

FAQ

What sieve diameters does the SS-25 support?
The SS-25 accepts standard 8 in (203 mm) and 12 in (305 mm) diameter test sieves, compatible with ASTM E11 and ISO 3310-1 frame dimensions.
Is the 45° tilt angle adjustable?
No—the 45° inclination is fixed by mechanical design to ensure repeatable flow dynamics and eliminate user-induced variability.
Can the SS-25 be used for wet sieving?
No—it is engineered exclusively for dry-sieving applications; moisture-sensitive samples require alternative methods such as wet-suspension sieving or laser diffraction.
Does the unit include test sieves?
No—sieves are ordered separately based on application-specific mesh requirements (e.g., #100 stainless steel for pharmaceuticals, #200 nylon for food-grade materials).
What maintenance is required?
Routine cleaning of the hammer assembly and cabinet interior; annual verification of timer accuracy and rotational speed using calibrated tachometry—documentation templates provided in the Operator Manual.