Overview
ISO 17231:2017 specifies a standardized spray test method to determine the water repellency (resistance to surface wetting) of garment leather. Applicable to all leathers intended for clothing, the standard measures how the leather surface responds to a controlled spray of distilled or deionized water. It does not assess resistance to water penetration.
Key topics and technical requirements
- Principle: A fixed volume of water is sprayed onto a clamped leather test piece at 45°; spray rating is assigned by visual comparison with descriptive and photographic standards. Mass gain after spray gives the amount and percentage of water absorbed.
- Apparatus essentials:
- Funnel: 150 mm ± 2 mm diameter; overall funnel-to-nozzle distance 190 mm ± 2 mm.
- Metal spray nozzle: convex face with 19 holes of 0.9 mm ± 0.05 mm; flow time for 250 ml ± 5 ml is 27.5 s ± 2.5 s.
- Test-piece holder: concentric rings for 150 mm clamp, positioned so the specimen center is 150 mm ± 2 mm below nozzle, at 45.0° ± 2.5°.
- Balance readable to 0.001 g; distilled/deionized water meeting ISO 3696 (grade 3).
- Sampling & preparation: Cut three square test pieces (182 mm ± 2 mm) per ISO 2418; condition per ISO 2419.
- Procedure highlights: Mount the face that would be exposed in wear uppermost; spray 250 ml water; tap frame, compare to scale and note reverse wetting; blot and re-weigh.
- Results & reporting: Assign spray rating (ISO 1–5) based on wetting pattern, report mass absorbed and percentage, conditioning atmosphere, and any deviations. Annex A includes a photographic scale; Annex B lists example apparatus suppliers.
Applications and users
ISO 17231 is used by:
- Leather manufacturers for quality control of garment leather water repellency.
- Footwear and apparel product developers and R&D teams assessing surface treatments.
- Independent testing laboratories and certification bodies carrying out leather testing.
- Suppliers verifying performance of finishes, coatings, or hydrophobic treatments.
Practical uses include batch acceptance testing, comparative evaluation of finishing processes, and verifying claims about surface water repellency for garments.
Related standards
- ISO 2418 - Sampling location for leather tests
- ISO 2419 - Sample preparation and conditioning
- ISO 3696 - Water for analytical laboratory use (grade 3)
- Annex A references AATCC photographic scale equivalence for the spray ratings.
Keywords: ISO 17231, water repellency, spray test, garment leather, leather testing, spray rating, surface wetting, physical and mechanical tests.