ISO 9073-3:2023

Overview

ISO 9073-3:2023 - "Nonwovens - Test methods - Part 3: Determination of tensile strength and elongation at break using the strip method" - defines a standardized laboratory procedure to measure the breaking force and elongation at break of nonwoven materials. The method applies to specimens tested in a conditioned or wet state and specifies two strip widths: Option A (25 mm) and Option B (50 mm). The document preferentially uses constant-rate-of-extension (CRE) tensile testers and describes key test variables, sampling, conditioning, calibration and result reporting.

Key topics and requirements

• Test principle: Extend a strip specimen at a constant rate until rupture and record maximum force and elongation (at maximum force and at rupture).
• Specimen dimensions: Two options - 25 mm (Option A) and 50 mm (Option B) width; gauge length and pretension are defined in the standard.
• Test states: Supports testing in both conditioned (standard atmosphere) and wet conditions; wet tests use Grade 3 water (ISO 3696), a non‑ionic wetting agent and blotting paper.
• Apparatus: CRE tensile testing machines are specified as preferred; CRL machines are addressed for information (see ISO 2062:2009, Annex A) with a note that CRE and CRL results are not directly comparable.
• Machine verification and calibration: Requirements reference calibration and verification standards (e.g., ISO 7500-1, ISO 10012) and include verification of the clamping system and the total operating system.
• Procedure controls: Specifies gauge length, rate of extension, specimen mounting, handling of slippage and jaw breaks, and data capture (machine scales, autographic charts, or computer interfaces).
• Results and precision: Methods for calculating breaking force and elongation, expression of results, precision information and reporting requirements; an informative annex discusses causes of low precision.

Applications and users

• Who uses it: Materials testing laboratories, nonwoven manufacturers, quality assurance and R&D teams, regulatory bodies and suppliers.
• Practical applications: Performance verification and quality control for hygiene and medical nonwovens, filtration media, geotextiles, automotive interior materials, and consumer products where tensile strength and elongation are critical for product function and specification compliance.
• Benefit: Provides reproducible, internationally recognized test data to compare materials, control production, and support product specifications and claims.

Related standards

• ISO 2062:2009 (CRL machines, Annex A)
• ISO 139 (conditioning atmospheres)
• ISO 3696 (water for analytical use)
• ISO 7500-1, ISO 10012 (calibration/measurement management)
• ISO 186, ISO 2859-1, ISO 3951-1 (sampling)
• ISO 1421 and ISO 13934 series (tensile testing references)

Keywords: ISO 9073-3:2023, nonwovens, tensile strength, elongation at break, strip method, CRE tensile tester, wet testing, specimen width.