Overview
EN ISO 9073-8:2025 is a European and international standard specifying a test method for measuring the liquid strike-through time of nonwoven coverstocks using simulated urine. This method enables standardized comparisons of different nonwoven materials' ability to resist liquid penetration. While designed for laboratory testing of nonwoven coverstocks, it does not replicate actual in-use conditions of finished products such as diapers or sanitary pads. This updated standard, approved by CEN in October 2025, supersedes the 1998 version, refining procedures to enhance consistency and accuracy.
Key Topics
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Scope and Purpose
Provides a reliable, reproducible procedure to quantify how quickly simulated urine penetrates nonwoven coverstocks-a critical parameter for evaluating material performance, especially in hygiene products.
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Test Principle
A fixed volume (5 ml) of simulated urine is dispensed at a controlled rate onto the surface of a nonwoven specimen placed atop a reference absorbent pad. The time until the liquid passes completely through the coverstock (strike-through time) is measured electronically using corrosion-resistant electrodes embedded in a transparent strike-through plate.
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Materials and Reagents
- Simulated urine is a sodium chloride solution with controlled surface tension (~70 mN/m) to mimic human urine characteristics. Surface tension adjustments via surfactants are allowed but must be reported.
- A multi-layer reference absorbent pad of specific filter papers is used to standardize liquid absorption.
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Apparatus
Includes burette, magnetic-valve funnel, acrylic strike-through plate with electrodes, ring stand, baseplate, and an electronic timer with high sensitivity (0.01 s resolution).
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Preparation and Sampling
Specimens sized 125 mm × 125 mm are prepared, conditioned under standard atmospheric conditions, and tested in at least 10 replicates for statistical reliability.
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Data Reporting
Results are expressed as the mean strike-through time and the coefficient of variation for each nonwoven coverstock sample. The test report should detail all relevant parameters, including any deviations such as surfactant usage.
Applications
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Hygiene Product Development
Essential for manufacturers of diapers, incontinence pads, and sanitary products requiring precise control over liquid barrier properties of coverstocks.
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Quality Control and Material Comparison
Enables objective comparisons between alternative nonwoven materials, assisting in raw material selection and supplier evaluations.
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Research and Innovation
Facilitates testing of new fibers, finishes, or composites aimed at improving liquid strike-through resistivity and overall product comfort.
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Standardization Compliance
Assists companies in meeting international regulations and market requirements by providing verifiable test data aligned with ISO and CEN standards.
Related Standards
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ISO 139 – Standard Atmospheres for Conditioning and Testing Textiles
Provides environmental criteria for conditioning test specimens before testing.
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ISO 186 – Sampling to Determine Average Quality of Paper and Board
Guides representative sampling methods applicable to test specimen selection.
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ISO 3696 – Water for Analytical Laboratory Use
Covers specifications and test methods for water quality, important when preparing simulated urine.
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EN ISO 9073 Series
Includes various test methods for evaluating physical properties of nonwovens, such as tensile strength and permeability.
Adhering to EN ISO 9073-8:2025 guarantees consistent and comparably accurate measurement of liquid strike-through time for nonwoven coverstocks, fostering innovation and quality improvements in textile and hygiene industries worldwide.
