ISO 17190-3:2020

Overview

ISO 17190-3:2020 specifies a laboratory test method for determining the particle size distribution (PSD) of cross‑linked polyacrylate superabsorbent powders used in urine‑absorbing aids for incontinence. The method covers PSD measurement by sieve fractionation for particle sizes up to 850 µm, using mechanical sieve shaking. It applies to powdered, free‑flowing polymeric superabsorbent materials and clarifies that tapping equipment is not expected to give equivalent results.

Key topics and technical requirements

• Scope and applicability: PSD up to 850 µm for cross‑linked polyacrylate superabsorbent powders; applicable only when sieve shaking is used for separation.
• Sampling and conditioning: Samples must be equilibrated to laboratory conditions (preferred (23 ± 2) °C and (45 ± 15) % RH) and homogenized by rotating the container before test portion removal. ISO 187 is referenced for conditioning procedures.
• Apparatus and materials:
  • Analytical balance accurate to ±0.01 g.
  • 200 mm diameter stainless steel sieves (example hole sizes: 45, 106, 150, 300, 600, 850 µm), top lid and bottom pan.
  • Sieve shaker capable of holding the stack and grounded to avoid static.
  • Brush or HEPA‑filtered vacuum for cleaning (only for sieves >150 µm).
• Procedure highlights:
  • Standard test portion: 100.00 g ± 1.00 g.
  • Place sample on top sieve, secure stack, ground equipment, run shaker for defined amplitude/time settings (example settings provided for Retsch™ AS 200: amplitude 1.00 mm at 60 Hz or 1.44 mm at 50 Hz; time 8.0 min at 60 Hz or 10.0 min at 50 Hz).
  • Weigh each sieve (empty and post‑sieving) to calculate retained mass per fraction.
• Calculation and reporting: Report weight fraction percentages, test conditions, equipment make/model, number of specimens, deviations, and statistical measures (standard deviation or coefficient of variation) where calculated.
• Precision: Method validated with repeatability and reproducibility statistics across sieve fractions (detailed in the standard).

Practical applications and users

This standard is essential for:

• Manufacturers of incontinence products and superabsorbent polymers for quality control and batch release.
• Independent testing laboratories performing particle size analysis by sieve fractionation.
• R&D teams optimizing absorbency, retention and handling properties that are PSD‑dependent.
• Regulatory and compliance professionals documenting measurement methods and reporting consistent PSD data.

Practical benefits include reproducible PSD data for product specification, process control, and comparative benchmarking of superabsorbent powders.

Related standards and references

• ISO 187 (conditioning and testing atmosphere)
• EDANA reference procedures (for calibration of alternative equipment)
• NWSP 220.0 (related test methods referenced in the bibliography)

Keywords: ISO 17190-3, particle size distribution, sieve fractionation, polyacrylate superabsorbent powders, incontinence products, sieve shaker, PSD testing.