Overview
ISO 17232:2017 - Leather - Physical and mechanical tests - Determination of heat resistance of patent leather - specifies two standardized test methods to assess the heat resistance of patent leather. The standard defines Method A (a modified lastometer test) and Method B (the Zwik apparatus test). Both methods are applicable to patent leathers for all end uses and are intended for routine quality control, specification compliance and comparative testing.
Key topics and technical requirements
- Two test methods
- Method A (Lastometer): distend a perforated circular test piece with a steel ball (21.0 mm dia.) to a distension of 7.5 ± 0.05 mm, heat at 100 ± 5 °C for 180 ± 5 s (standard) or 125 ± 5 °C for 300 ± 5 s (extended), then inspect for damage to the patent finish and leather grain.
- Method B (Zwik): stretch a perforated rectangular test piece over a mandrel (half-cylinder radius 15.0 mm) to a linear extension of 21 ± 1 %, preheat the mandrel (125 ± 5 °C), apply a timed heat and pull sequence (including 20 ± 2 s then 300 ± 5 s at 125 °C), and inspect for surface damage.
- Sampling & preparation
- Method A: cut three test pieces (ISO 2418), perforate centrally (needle PCL size 80 or appropriate), condition per ISO 2419.
- Method B: cut six test pieces (three parallel and three perpendicular to backbone), perforate along centre line, condition per ISO 2419.
- Apparatus & measurement
- Specified clamps, plunger, temperature measuring device (±1 °C), hot air blower, stopwatch and dimensional tolerances for fixtures.
- Reporting requirements
- Reports must reference ISO 17232:2017 and include details of observed damage, test temperature/time, conditioning atmosphere, sampling details and any deviations.
Applications and who uses this standard
ISO 17232:2017 is used by:
- Leather manufacturers and patent leather finishers for product development and batch quality control.
- Footwear and fashion brands that specify heat-resistant patent leather components.
- Independent testing laboratories and conformity assessment bodies performing standardized physical and mechanical tests.
- R&D teams evaluating new finishes, coatings or processing changes affecting heat resistance.
Practical applications include acceptance testing of incoming leather, validation of finishing processes, failure analysis of heat-related discoloration, blistering or cracking, and supporting material specifications in supply chains.
Related standards
- ISO 2418 - Sampling location for leather testing.
- ISO 2419 - Sample preparation and conditioning for physical and mechanical tests.
- EN 15987 - Leather terminology (key definitions).
- IULTCS/IUP 38 - The IULTCS method on which ISO 17232 is based.
Keywords: ISO 17232:2017, patent leather heat resistance, lastometer, Zwik, leather testing, physical and mechanical tests.
