Overview
EN ISO 4674-2:2021 - "Rubber- or plastics-coated fabrics - Determination of tear resistance - Part 2: Ballistic pendulum method" - specifies a dynamic test method for measuring tear resistance of coated textiles. The test uses the kinetic energy of a falling pendulum to apply a sudden force to a notched specimen and determines tearing force from the amplitude of the first pendulum swing. The standard covers tests on specimens conditioned in a standard atmosphere or after pre-treatment (for example, water immersion). Results from this ballistic pendulum method are not comparable with results from constant rate tear methods.
Key topics and technical requirements
- Principle: Measurement of tear propagation from an initiating cut by a sudden (dynamic) force generated by a pendulum; tearing force derived from first-oscillation amplitude.
- Apparatus: Pendulum test machine with rigid framework, roller bearings, release mechanism, knife and measuring device. The movable jaw is integral with the pendulum; the fixed jaw is attached to the frame.
- Jaw spacing: Clamping faces are required to be in the same plane and 2.8 mm ± 0.3 mm apart to permit passage of the knife.
- Measurement: Mechanical or electronic device to determine maximum amplitude of the first swing; readings may be given directly as tearing force.
- Specimen handling: Clause coverage includes sampling, specimen shape and dimensions, number of specimens, conditioning and pre-treatment (e.g., water immersion) and time interval between manufacture and testing.
- Atmosphere: Conditioning and testing atmospheres referenced to ISO 2231 (standard atmospheres) to ensure reproducibility.
- Limitations: Explicitly states the method differs from constant-rate methods (see ISO 4674-1) and results are not interchangeable.
Applications and users
Who uses EN ISO 4674-2:2021:
- Coated-fabric manufacturers for quality control and production monitoring.
- Independent testing laboratories performing material characterization and compliance testing.
- R&D teams evaluating new coating formulations, substrates or treatments (including wet pre-treatments).
- Specifiers, procurement professionals and standards writers who need a standardized, repeatable dynamic tear-resistance method for product specifications or acceptance criteria.
Practical uses:
- Assessing tear propagation behavior under sudden loads (impact-like conditions).
- Comparing effects of coating types, adhesives or wet treatments on tear performance.
- Verifying material performance for applications where dynamic tearing is a concern (tents, protective covers, inflatable structures, industrial tarpaulins).
Related standards
- ISO 4674-1 - Part 1: Constant rate of tear methods (different principle; not directly comparable).
- ISO 2231 - Standard atmospheres for conditioning and testing (referenced).
- ISO 2286-2 - Related test methods for coated fabrics (referenced).
Keywords: EN ISO 4674-2:2021, ballistic pendulum method, tear resistance, rubber-coated fabrics, plastics-coated fabrics, coated textiles testing, dynamic tear test, conditioning, wet test.