ISO 9073-12:2002

Overview

ISO 9073-12:2002 - Textiles - Test methods for nonwovens - Part 12: Demand absorbency defines a laboratory method to evaluate the demand absorbency (also called demand wettability) of fabrics and nonwoven materials. The test measures how much liquid a sample absorbs when one face is in contact with a liquid under a defined mechanical pressure. It is intended for comparative assessment of absorbent materials and not to simulate in-use conditions of finished products.

Key topics and technical requirements

• Principle: A test piece is placed on a specified porous plate connected by a siphon to a liquid reservoir. Absorption is recorded as the decrease in reservoir mass versus time.
• Measured outputs:
  • Maximum absorbed mass (A) - mass of liquid absorbed when mass change stabilizes.
  • Demand absorbency capacity (DAC) - A divided by sample mass (g/g).
  • Maximum absorption rate (MAR) - maximum absorption rate calculated over a 1 s period (g/s); special rules for very fast materials.
• Apparatus highlights:
  • Porous glass plate: ~60 mm diameter, 4 ± 1 mm thick, porosity rating 2 (4 µm–90 µm), target flow 2.5–3.5 g/s (see calibration Annex A).
  • Reservoir and siphon assembly with specified tube diameters and alignment.
  • Electronic balance accurate to 0.01 g and a data acquisition system capable of ≥4 readings/s (higher rates for very fast-absorbing materials).
  • Hydrophobic foam and cylindrical weight providing an imposed pressure of ~2.50 kPa (total weight ≈ 605 g).
• Procedure essentials: Cut conditioned 55 mm test pieces (five replicates), affix to foam/weight, start data acquisition, record reservoir mass until absorption stabilizes (mass change <1% over previous 5 s), compute A, DAC, MAR.
• Reporting: Include A vs. t data and curves, DAC and MAR individual results and statistics, test liquid identification (surface tension and temperature), any deviations.

Applications and users

ISO 9073-12 is used for:

• Comparative evaluation in R&D and quality control of nonwovens, wipes, absorbent hygiene components, medical textiles, filtration media and other absorbent substrates.
• Supplier qualification, material selection, benchmarking and product development where quantitative absorbency metrics (DAC, MAR) are required.

Typical users:

• Textile testing laboratories, nonwoven manufacturers, product R&D teams, standards and conformity assessment bodies.

Related standards

• Other parts of ISO 9073 (e.g., Part 1 mass per unit area; Part 6 absorption; Part 8 liquid strike-through).
• ISO 139 (conditioning atmospheres) and ISO 3696 (water for analytical use) are normative references used by this test method.

Keywords: ISO 9073-12:2002, demand absorbency, nonwovens test methods, DAC, MAR, absorbency testing, porous plate siphon, textile testing.