Overview
ISO 32100:2018 specifies a laboratory test method - the flexometer method - for determining the flex resistance of rubber- or plastics‑coated fabrics in the folded condition. The method measures how the coated fabric surface changes after a defined number of flex cycles (a complete to‑and‑fro movement) by causing a fold to run along a clamped test specimen and grading visible damage under a ×6 magnifier. The procedure applies only to products that can be clamped in the apparatus and where a running fold can be produced.
Key topics and requirements
- Scope and applicability
- Applicable to rubber- or plastics-coated fabrics that can be clamped and produce a running fold; not suitable for very thick or stiff products (see Annex A).
- Test specimens
- Typical specimen size 70 mm × 45 mm (special shapes covered); at least three specimens cut longitudinally and three transversely.
- Conditioning in standard atmosphere B per ISO 2231 (23 °C, 50% r.h.).
- Apparatus and settings
- Flexometer with movable upper clamp and fixed lower clamp; counter; magnifier (×6); mandrel (10 mm diameter, min. 70 mm).
- Upper clamp reciprocates through 22.5° ± 0.5° at 100 cycles/min ± 5 cycles/min; gap and positioning tolerances specified (e.g., 25.0 mm ± 0.5 mm vertical distance).
- Procedure
- Fold specimen so test surface faces inward on one clamp and outward on the other, clamp without elongation, run agreed flex number or intervals, periodically inspect.
- Repositioning rules, handling of pressure marks, and wet specimen inspection are defined to ensure reproducibility.
- Assessment and reporting
- Damage graded using a 0–5 scale (from no change to complete coating break/holes).
- Test report must reference ISO 32100:2018, specimen orientation, conditioning, flex number or intervals, grades per specimen, deviations and date.
Practical applications
- Use ISO 32100:2018 to evaluate durability and folding performance of coated textiles where repeated bending/folding occurs.
- Typical uses include quality control, product development, acceptance testing, comparative assessment of coating formulations and backing constructions.
- Results inform material selection, specification writing, and supplier or contractual quality requirements related to flex resistance.
Who uses this standard
- Textile and coatings manufacturers, independent test laboratories, R&D teams, quality assurance professionals, and procurement/specification engineers working with rubber- or plastics-coated fabrics.
Related standards
- ISO 2231 - Standard atmospheres for conditioning and testing (normative reference in ISO 32100).
- ISO 2768‑1 tolerances are referenced for drawing tolerances shown in the standard.
Keywords: ISO 32100:2018, flex resistance, flexometer method, rubber-coated fabrics, plastics-coated fabrics, flex cycles, flex number, coated textiles, physical and mechanical tests.
Open preview (PDF)Rubber- or plastics-coated fabrics — Physical and mechanical tests — Determination of flex resistance by the flexometer method