Gilson SS-21F Silent Sifter® Rotational Sieve Analyzer with Integrated Sieving Stack and Acoustic Damping Enclosure

Overview

The Gilson SS-21F Silent Sifter® is a precision-engineered rotational sieve analyzer designed for standardized particle size distribution analysis in compliance with ASTM E11, ISO 3310-1, and USP <786>. Unlike conventional vibratory or rotary sieves, the SS-21F employs a dual-roller driven, low-inertia rotational motion combined with controlled tapping—generating consistent, reproducible energy input to the sieve stack without inducing high-frequency mechanical resonance. Its core architecture integrates acoustic isolation at the system level: a fully enclosed cabinet constructed from dense MDF with vibration-dampening mounting, sealed gasketed access door, and UHMW-PE hammer heads that minimize impact noise generation during tapping cycles. This design reduces operational sound pressure levels by 7–10 dB(A) compared to legacy rotary sifters—bringing typical operating noise to ≤68 dB(A) at 1 m—while maintaining full fidelity to sieve efficiency, mass recovery, and repeatability per ISO 565 and ASTM C136 protocols.

Key Features

• Acoustically optimized enclosure with gasket-sealed hinged door and dense MDF cabinet walls, engineered to attenuate airborne and structure-borne noise without compromising airflow or thermal management
• Dual stainless steel drive rollers with rubberized surface finish ensure uniform, non-slip rotation of sieve stacks up to 20 × 8-inch (203 mm) half-height frames or 6 × 12-inch (305 mm) full-height frames
• UHMW-PE tipped aluminum hammer assembly (6061-T6 alloy body) delivers repeatable kinetic energy transfer while eliminating metal-on-metal impact noise
• Digital countdown timer with ±1-second accuracy, programmable up to 99 minutes; includes pause/resume functionality and audible 5-second completion alert
• Ergonomic rotary latch knob enables tool-free, single-motion stack loading and secure positioning—no clamps or alignment fixtures required
• Integrated floor stand with dual-locking 4-inch casters (two swivel, two rigid) ensures stable mobility and OSHA-compliant workstation anchoring
• 1/4 HP continuous-duty motor rated for 230 V / 50 Hz operation (5.4 A), thermally protected and UL-listed for laboratory use

Sample Compatibility & Compliance

The SS-21F accommodates standard ASTM E11 and ISO 3310-1 test sieves in diameters of 200 mm (8 in) and 300 mm (12 in), supporting full-height, half-height, and intermediate-height configurations. It accepts sieve meshes ranging from 1 in (25.4 mm) down to No. 635 (20 µm), enabling granulometric analysis across aggregates, soils, pharmaceutical powders, catalysts, and mineral concentrates. All mechanical motion parameters—including rotational speed, tap frequency, and dwell time—are fixed per ASTM D6913 and ISO 13320 recommendations to ensure inter-laboratory comparability. The sealed cabinet meets OSHA 29 CFR 1910.95 requirements for hearing conservation zones and supports GLP-compliant environments where dust containment (e.g., crystalline silica, quartz) is mandated under NIOSH REL and OSHA PEL guidelines.

Software & Data Management

The SS-21F operates as a standalone electromechanical instrument with no embedded firmware or network interface. Its digital controller provides tactile button inputs and a high-brightness 0.5-inch (12.7 mm) 7-segment LED display (126 mm total width) for ambient-light readability in ISO Class 7 cleanrooms or industrial QA labs. While it does not generate electronic data logs, its timing accuracy (±1 s), repeatable mechanical actuation, and physical traceability—via stamped calibration labels, user logbooks, and documented sieve certification (per ISO/IEC 17025-accredited providers)—support audit readiness for FDA 21 CFR Part 11–aligned workflows when paired with external LIMS or ELN systems. Optional accessories such as SSA-76 replacement timers include identical display and timing logic for seamless maintenance continuity.

Applications

• Aggregate gradation testing per ASTM C136/C136M and AASHTO T 27 in civil engineering laboratories
• Soil particle-size analysis per ASTM D6913 and USDA texture classification protocols
• Pharmaceutical powder characterization per USP <786> and EP 2.9.31 for blend uniformity and dissolution predictability
• Mineral processing QC for flotation feed sizing, tailings classification, and grinding circuit optimization
• Catalyst and battery material screening where electrostatic or friable particles require low-energy separation
• Food ingredient grading (e.g., flour, sugar, starch) under SQF and BRCGS-aligned quality control frameworks

FAQ

What voltage and frequency does the SS-21F operate on?
The SS-21F is configured for 230 V AC, 50 Hz operation with a nominal current draw of 5.4 A.
Can the SS-21F accommodate both ASTM and ISO test sieves?
Yes—it accepts standard 200 mm (8 in) and 300 mm (12 in) diameter sieves compliant with ASTM E11 and ISO 3310-1 specifications.
Is the unit compliant with occupational noise exposure regulations?
Yes—the SS-21F achieves ≤68 dB(A) at 1 meter distance, meeting OSHA’s permissible exposure limit (PEL) for an 8-hour TWA and reducing reliance on administrative controls or PPE in routine operation.
Does the SS-21F require calibration certification?
While the device itself is not calibrated, users must maintain certified traceable sieves (e.g., NIST-traceable mesh counts) and document operational parameters (time, stack configuration) per ISO/IEC 17025 and GLP requirements.
What maintenance intervals are recommended for the hammer assembly and drive rollers?
Gilson recommends visual inspection before each use; UHMW-PE hammer tips should be replaced after 1,000 operational hours or upon visible wear, and drive roller surfaces cleaned weekly with isopropyl alcohol to prevent particulate buildup.