ISO 9073-8:1995

Overview - ISO 9073-8:1995 (Textiles - Nonwovens - Liquid strike-through time)

ISO 9073-8:1995 specifies a laboratory method for measuring the liquid strike-through time of nonwoven coverstocks using simulated urine. The procedure times how long a defined volume of simulated urine takes to pass through a nonwoven sample into a reference absorbent pad. The method is intended for comparative testing of nonwoven materials and does not simulate in-use conditions for finished products (e.g., diapers or pads).

Key topics and technical requirements

• Test principle: A measured volume (5.0 ml) of simulated urine is discharged onto a nonwoven test piece; electronic timing starts when liquid bridges electrodes and stops when penetration is complete.
• Simulated urine: 9 g/l sodium chloride solution in Grade 3 water (ISO 3696) with a surface tension of 70 ± 2 mN/m. Surface tension must be checked before each series; any surfactant addition must be reported.
• Reference absorbent pad: Five layers of filter paper (100 mm × 100 mm) with a specified strike-through benchmark (mean ~3 ± 0.5 s in 10 determinations).
• Apparatus: 50 ml burette, funnel with magnetic valve (discharge characteristics specified), strike-through plate with corrosion‑resistant electrodes (1.6 mm platinum or stainless wire), transparent baseplate (~125 × 125 × 5 mm), and an electronic timer readable to 0.01 s.
• Samples & conditioning: Cut 10 test pieces (125 mm × 125 mm recommended) and condition them per ISO 139 standard atmospheres.
• Results reporting: Individual strike-through times, mean time, coefficient of variation, conditioning atmosphere, any deviations (e.g., surfactant use).

Practical applications and users

ISO 9073-8 is used to:

• Compare liquid penetration performance of nonwoven coverstocks in product development and material selection.
• Support quality control and batch-to-batch consistency checks for nonwoven manufacturers.
• Provide standardized data for R&D teams optimizing liquid-handling surfaces in hygiene products (e.g., diaper topsheets, medical pads).
• Supply test laboratories with a reproducible method for reporting strike-through times.

Primary users:

• Nonwoven fabric manufacturers
• Personal hygiene and medical absorbent product developers
• Accredited testing laboratories and quality assurance teams
• Procurement and specification engineers assessing coverstock performance

Related standards

• ISO 9073 (series) - Test methods for nonwovens (other parts: mass, thickness, tensile, tear, drape, etc.)
• ISO 139 - Standard atmospheres for conditioning and testing
• ISO 186 - Sampling to determine average quality
• ISO 3696 - Water for analytical laboratory use

Keywords: ISO 9073-8, nonwovens test methods, liquid strike-through time, simulated urine, nonwoven coverstock, absorbent pad testing, textile testing, hygiene product development.