ISO 17190-9:2020

Overview

ISO 17190-9:2020 specifies a gravimetric test method for determining the mass flow rate (flowability) and bulk (apparent) density of polyacrylate superabsorbent powders used in urine‑absorbing aids for incontinence. The standard defines laboratory conditioning, sampling, apparatus, a step‑by‑step procedure, calculation formulas and reporting requirements to ensure consistent, comparable measurements of superabsorbent polymer (SAP) powder handling properties.

Key topics and technical requirements

• Scope: Mass flow rate (g/s) and bulk density (g/ml) of polyacrylate SAP powders.
• Conditioning: Preferred test atmosphere is (23 ± 2) °C and (45 ± 15) % RH (ISO 187 referenced).
• Sampling: Homogenize containers by a three‑dimensional figure‑of‑eight motion; remove lumps >1 mm.
• Apparatus (examples of specified dimensions):
  • Density cup: stainless steel, 100.0 ± 0.5 ml capacity.
  • Funnel: polished stainless steel, orifice 10.00 ± 0.01 mm, cone angle 20°, height 145 mm.
  • Analytical balance (0.01 g readability), timer, ring stand, beaker.
• Procedure:
  • Use a (100.00 ± 0.01) g test portion.
  • Pour through the funnel into the density cup, time the discharge to obtain flowability (time in s).
  • Weigh cup before and after to compute bulk density.
• Calculations:
  • Flow rate (q) = mass / time (g/s).
  • Bulk density (ρ) = mass in cup / cup volume (g/ml).
  • Report results to specified significant figures and average duplicate determinations.
• Precision and validated ranges: Method validated for flow rate ~9.5–13.46 g/s and density ~0.66–0.72 g/ml. Repeatability and reproducibility statistics are provided in the standard.
• Safety note: Guidance on respirable SAP dust (MAK guideline 0.05 mg·m‑3) and handling precautions are included.

Applications and who uses it

• Manufacturers of urine‑absorbing aids (diapers, pads, medical incontinence products) for quality control of SAP properties.
• R&D and product development teams evaluating powder flowability and packing density for dosing, processing and absorbency performance.
• Third‑party testing laboratories and regulatory/ conformity assessment bodies reporting standardized material data.
• Suppliers of SAP powders for acceptance testing and specification compliance.

Practical value

• Ensures reproducible characterization of SAP powder behavior during filling, mixing and manufacturing.
• Helps optimize handling, dosing equipment and product formulation by providing quantitative flow and density data.
• Standardized reporting supports supplier‑customer communication and performance benchmarking.

Related standards

• ISO 17190 series (other parts addressing SAP materials and test methods)
• ISO 187 (conditioning and monitoring of test atmosphere)