Overview
EN ISO 7854:1997 (ISO 7854:1995) specifies laboratory methods to determine the resistance of rubber- or plastics-coated fabrics to damage by repeated flexing. It replaces the first edition and standardizes three established flex-fatigue tests - De Mattia (Method A), Schildknecht (Method B) and the crumple/flex (Method C) - including sample preparation, apparatus criteria, test procedures, inspection and reporting. The standard emphasizes repeatability, conditioning atmospheres and limits of correlation between methods.
Key topics and technical requirements
- Three test methods
- Method A (De Mattia): Small folded strip flexed at high speed; suitable when material cannot be mounted for other methods or sample size is limited.
- Method B (Schildknecht): Test strip mounted around opposing cylinders that reciprocate to compress/relax the cylinder; suitable for light to medium-duty coated fabrics.
- Method C (Crumple/flex): Large cylindrical specimen mounted between flanged discs with combined twisting and compression; suited for severe flexing conditions and allows post-flex tests (e.g., hydrostatic head).
- Apparatus and parameters: The standard defines specific machine characteristics (e.g., frequencies, stroke lengths and geometry), clip/mounting details and test-piece dimensions for each method to improve reproducibility.
- Sample preparation and selection: Specifies the number, orientation (longitudinal/transverse), sizes and location across roll width to reduce variability.
- Conditioning and atmosphere: Tests must be conducted in specified standard atmospheres (ISO 2231 types A/B/C) and care must be taken to control air temperature and ventilation to avoid micro-climate or thermal artefacts.
- Examination and reporting: Guidance on inspection intervals, criteria for termination (number of cycles or observed damage), assessment of severity and mandatory test report items (method reference, identification, cycles to failure, damage severity, deviations).
Practical applications
- Assessing flex-fatigue durability of coated fabrics used in outdoor clothing, inflatable products, industrial covers, tarpaulins, conveyor belts and protective equipment.
- Selecting or validating coatings and substrate combinations for service life under repeated bending.
- Supporting product specifications, quality control, and comparative evaluations for R&D and manufacturing.
Who uses this standard
- Textile and rubber test laboratories, product designers, materials engineers, quality managers, and manufacturers of coated fabrics and coated textile products.
Related standards
Keywords: EN ISO 7854:1997, ISO 7854:1995, rubber- or plastics-coated fabrics, flexing resistance, De Mattia, Schildknecht, crumple/flex, coated fabrics durability testing, flex fatigue.