EN ISO 26082-2:2012 (ISO 26082-2:2012) defines the tumbling method for assessing the resistance of all forms of leather to visible soiling caused by repeated contact with soiled objects. The standard describes a controlled soiling treatment using soiled felt cubes tumbled in a rotating cylinder and a procedure to determine the end‑point by measuring colour transfer to a standard fabric. It also specifies a physical pretreatment routine to simulate wear for leathers that may lose soiling resistance in service.
Key topics and technical requirements
- Scope and principle: Repeated impacts of soiled felt pads against a test specimen in a rotating container; end-point determined by colour change on a reference fabric.
- Reagents and soiling mixture: Uses a defined synthetic sebum formulation (with components such as lanolin, beef tallow, free fatty acids) diluted in solvents and amended with colloidal graphite to produce a soiling solution.
- Soiled felt cubes: White wool‑rich felt cubes (≈12.5 mm sides), 160 cubes per test, saturated with the soiling solution and dried (oven at 60 ± 2 °C for ~3 h).
- Apparatus and machine parameters: Tumbling soiling machine with cylinders (internal length 300 ± 10 mm, internal diameter 100 ± 5 mm), rotation speed (24 ± 2 r/min) with direction change every 10 minutes; cylinders positioned tangential to the axis of rotation.
- Sampling and conditioning: Circular test specimens (96 ± 1 mm) cut per ISO 2418; conditioning per ISO 2419.
- Physical pretreatment (if required): Light abrasion (e.g., 100 revolutions with SiC paper grit 180 at ~12 kPa) followed by 100 000 cycles dry flexing to simulate service wear-details must be reported.
- Assessment and end‑point: Colour measurement using a colorimeter (ISO 105‑A04) and visual grading with grey scales (ISO 105‑A02/A03) to assess staining and colour change.
Applications - who uses this standard
- Leather manufacturers and tanneries - quality control and batch acceptance for upholstery, footwear, automotive interiors and other leather goods.
- Independent test laboratories - standardized method for comparative testing of soiling resistance and finish durability.
- Product developers and specification writers - to validate coatings, top‑finishes and cleaning/resistance claims.
- Procurement and compliance teams - include in technical specifications and supplier contracts to ensure reproducible soiling performance.
Related standards
- ISO 26082-1 - Rubbing (Martindale) method (companion method for soiling)
- ISO 105-A02/A03/A04/F09 - Colour fastness and assessment methods
- ISO 2418, ISO 2419 - Sampling, conditioning and sample preparation for leather
- ISO 12947-1 - Martindale abrasion apparatus (referenced for abrasion pretreatment)
Keywords: leather soiling test, tumbling method, EN ISO 26082-2:2012, synthetic sebum, felt cubes, soiling resistance, leather testing, colourimeter, pretreatment, quality control.
