Overview
EN ISO 17235:2015 (ISO 17235:2015) specifies a non-destructive method for determining the softness of leather. Adopted by CEN, this international standard applies to all non-rigid leathers - for example shoe upper leather, upholstery leather, leathergoods leather, and apparel leather. The method measures leather distension when a defined cylindrical load pin and mass are lowered onto a clamped leather area, giving a repeatable softness value useful for quality control and product development.
Key Topics
- Principle: A cylindrical rod of defined mass is lowered at a controlled rate onto leather; the vertical distension is recorded as softness.
- Apparatus requirements:
- Circular apertures: nominal diameters 35 mm, 25 mm, 20 mm (±0.1 mm).
- Cylindrical load pin: diameter 4.9 mm ±0.1 mm, length 11.5 mm ±0.1 mm, attached to a cylindrical load; total mass 530 g ±10 g.
- Vertical travel limited to 11.5 mm ±0.1 mm and lowering time 1.5 s ±0.5 s.
- Gauge with 0.1 mm resolution to read distension.
- Flat metal disc (min. 60 mm) for zeroing the gauge.
- Forces: Effective static test force combines the load (≈5.20 N) and a linearly decreasing spring force, resulting in a total test force in the range ≈6.13 N to 5.5 N over the measurement travel.
- Sampling & conditioning: Samples are conditioned per ISO 2419 and sampling locations follow ISO 2418. Measurements can be taken without cutting the hide.
- Procedure & reporting:
- Zero the gauge with metal disc, clamp leather over the aperture, release load pin and record steady reading.
- Test at least three non-overlapping areas; report individual readings and the mean.
- Test report must cite ISO 17235, apertures used, sample IDs, atmosphere, deviations, and readings.
Applications
- Quality control in tanneries and leather-processing plants to verify product softness specifications.
- Footwear and upholstery manufacturers to ensure comfort and handling characteristics meet design requirements.
- Leathergoods and apparel R&D for material comparison, supplier evaluation, and product development.
- Third‑party test laboratories providing certification and comparison testing.
Who uses it: leather technologists, quality managers, product developers, test laboratories, and standards compliance teams.
Related Standards
- ISO 2418 - Leather: sampling location.
- ISO 2419 - Leather: sample preparation and conditioning.
Keywords: EN ISO 17235:2015, ISO 17235:2015, leather softness test, non-destructive softness measurement, leather physical and mechanical tests, shoe upper leather, upholstery leather.