ISO 20158:2018 PDF

Overview

ISO 20158:2018 - Textiles - Determination of water absorption time and water absorption capacity of textile fabrics - specifies laboratory test methods to measure how quickly textile fabrics wet out and how much water they absorb when saturated. The standard targets fabrics designed to absorb water, commonly used in cleaning products such as cloths and mops, including waffle, chamois, bubble looped, checkered, terry looped, and multilayer materials.

Keywords: ISO 20158, water absorption, textile fabrics, water absorption time, water absorption capacity, textile testing.

Key topics and requirements

• Scope: Test methods for all water-absorbing textile fabrics intended for cleaning tasks.
• Specimens: Cut 12 specimens from each sample - 100 mm × 100 mm each; mark six for face/back testing. Avoid selvedge areas (within 150 mm).
• Conditioning: Follow the standard atmosphere per ISO 139 before testing (at least 24 h).
• Apparatus & materials:
  • Container with minimum depth 100 mm
  • Analytical balance with ±0.001 g accuracy
  • Timer with ±0.1 s accuracy
  • Grade 3 laboratory water per ISO 3696 at (20 ± 2) °C (unless otherwise agreed)
• Procedure (summary):
  • Weigh dry specimen, float it onto the water surface, start timer and record water absorption time to 0.1 s.
  • If absorption exceeds 180 s, report as “More than 180 s”.
  • For water absorption capacity (WAC): immerse, allow fixed saturation time (120 ± 2) s (or 240 ± 2 s if >180 s), drain vertically for (60 ± 2) s, then weigh wet specimen.
• Result expression:
  • Mean water absorption time for six specimens (to 0.1 s).
  • Water absorption capacity (WAC %) per specimen using: WAC (%) = ((m2 − m1) / m1) × 100, where m1 = dry mass, m2 = wet mass; report the mean of six results.
• Reporting: Include reference to ISO 20158, sample identification, testing conditions, water temperature, individual and average times and capacities, deviations, and test date.

Applications and users

ISO 20158 is practical for:

• Textile testing and quality control laboratories
• Manufacturers of cleaning cloths, mops, and absorbent household textiles
• Product development teams specifying absorbency performance
• Procurement and compliance teams requiring standardized absorbency data It helps ensure consistent, repeatable measurement of wetting behavior and absorbent capacity for performance claims, R&D comparisons, and quality acceptance.

Related standards

• ISO 139 - Standard atmospheres for conditioning and testing textiles
• ISO 3696 - Water for analytical laboratory use (Grade 3)
• Prepared by ISO/TC 38 (Textiles)

For implementation, refer to the full ISO 20158:2018 document for complete procedural detail and official test clauses.