ISO 26082-2:2012

Overview

ISO 26082-2:2012 - Leather: Physical and mechanical test methods for the determination of soiling - Part 2: Tumbling method specifies a controlled tumbling procedure to evaluate the resistance of leather to visible soiling caused by repeated contact with soiled objects. The standard defines the test principle, required reagents (notably a synthetic sebum/colloidal graphite soiling solution), equipment, sample preparation and an optional physical pretreatment to simulate in-service wear for leathers that may lose soiling resistance.

Key topics and technical requirements

• Test principle: Soiled felt pads are tumbled in a rotating cylinder so they impact a fixed leather specimen; change in colour of a standard cotton fabric determines the treatment end-point.
• Soiling solution and pads: Uses a synthetic sebum mix with colloidal graphite; 160 wool-rich felt cubes are prepared, oven-dried (60 ± 2 °C for ~3 h) and conditioned.
• Tumbling machine specs: Cylinders ~300 mm long × 100 mm internal diameter, rotation ~24 ± 2 r/min, direction change every 10 min; 40 soiled cubes per cylinder.
• End-point control: Colour change of standard cotton measured by a colorimeter (CIELAB, CIE 10° observer, illuminant D65); target mean ΔE (CIELAB) ≈ 20.0 ± 1.0 to standardize soiling level.
• Assessment: Staining rated against grey scales (ISO 105-A02 / A03) with half-step ratings; visual inspection required for pretreated leathers.
• Optional pretreatment (wear simulation): Light abrasion (silicon carbide ~180 grit, nominal 12 kPa) followed by 100 000 dry flex cycles using Maeser-type flexing (≈90 cycles/min, ~32° flex) to simulate upholstery wear. Details of any pretreatment must be reported.
• Equipment & measurement: Requires colorimeter compliant with ISO 105-A04, Maeser flexing machine, Martindale abrasion tester (if needed), and specified sampling/conditioning per ISO 2418 / ISO 2419.

Applications and users

• Quality control and acceptance testing of upholstery, footwear, garments and automotive leathers where soiling resistance is a performance concern.
• R&D and formulation teams assessing finishes, coatings or cleaning treatments.
• Independent testing laboratories and compliance bodies specifying reproducible leather soiling tests.
• Procurement/specification writers who need objective criteria for product selection and warranty claims.

Related standards

• ISO 26082-1 (Part 1: Rubbing / Martindale method)
• ISO 105-A02, A03, A04, F09 (colourfastness / staining and cotton rubbing cloth)
• ISO 12947-1 (Martindale abrasion apparatus)
• ISO 2418, ISO 2419 (leather sampling, sample preparation and conditioning)

Keywords: ISO 26082-2:2012, leather soiling test, tumbling method, soiling resistance, synthetic sebum, felt cubes, CIELAB ΔE, leather testing, upholstery leather.