ISO 17190-5:2020

Overview

ISO 17190-5:2020 specifies a laboratory test method for measuring the free swell capacity of polyacrylate superabsorbent powders (SAPs) used in urine-absorbing aids for incontinence. The method uses gravimetric measurement in 0.9% saline to determine how much fluid a known mass of polymer absorbs under free-swelling conditions. This standard is part of the ISO 17190 series covering polymer-based absorbent materials for incontinence products.

Key topics and requirements

• Scope: Determination of free swell capacity (mass fraction, g/g) of polyacrylate superabsorbent powders in saline.
• Test fluid: 0.9% sodium chloride solution prepared with Grade 3 water (ISO 3696); typical conductivity ≈ 1600 μS/m at 25 °C; recommended test temperature (23 ± 2) °C.
• Sample portion: 0.180–0.220 g of dry SAP per test specimen, placed in a water-permeable nonwoven “teabag”.
• Teabag specification: Non-apertured heat-sealable nonwoven of defined dimensions and properties (example: 60×40 mm to 60×85 mm).
• Procedure highlights:
  • Weigh dry sample (ms), seal in teabag, immerse in saline for 30 minutes.
  • Remove and hang teabag from a corner for 10 minutes to drip off excess liquid.
  • Weigh wet teabag (mw); run blanks to correct for bag uptake.
• Calculation: Free swell capacity (g/g) computed from the dry mass, wet bag mass and blank average to give absorbed mass per gram of polymer.
• Reporting: Include sample ID, method reference (ISO 17190-5:2020), test conditions, equipment, raw and averaged results (g/g), deviations, and any statistical measures.
• Safety and quality: Guidance on conditioning (23 ± 2 °C, 45 ± 15 % RH per ISO 187), sample homogenization, and respirable dust precautions (guideline value noted for respirable SAP dust).

Applications and users

• Who uses it: R&D laboratories, quality control teams, regulatory testing bodies, and manufacturers of diapers, pads, and other incontinence products.
• Practical value:
  • Establishes consistent, reproducible data for SAP absorption performance in saline/urine-like conditions.
  • Supports product formulation, comparative benchmarking, QC acceptance criteria, and supplier evaluation.
  • Helps correlate material performance (free swell capacity) with retention and wearing comfort in end products.

Related standards

• ISO 17190 series (other parts for absorbent material characterization)
• ISO 3696 - Water for analytical laboratory use
• ISO 187 - Standard atmosphere for conditioning and testing

Keywords: ISO 17190-5:2020, polyacrylate superabsorbent powders, free swell capacity, saline, gravimetric measurement, urine-absorbing aids, incontinence, test method.