Overview - EN ISO 3380:2015 (Leather shrinkage temperature test)
EN ISO 3380:2015 (ISO 3380:2015) specifies a standardized method to determine the shrinkage temperature of leather up to 100 °C. Published jointly by CEN and ISO (IULTCS collaboration), the standard is applicable to all types of leather and is used to assess thermal stability related to tanning and collagen structure. Keywords: EN ISO 3380:2015, shrinkage temperature, leather testing, leather physical tests.
Key topics and technical requirements
- Scope: Measurement of the temperature at which a leather test piece exhibits sudden shrinkage when heated in water (up to 100 °C).
- Referenced standards: ISO 2418 (sampling location), ISO 2589 (thickness measurement), ISO 3696 (laboratory water quality).
- Apparatus essentials:
- Vessel (min. 500 ml, working depth ≥110 mm); can be pressurized for >100 °C.
- Fixed and movable test-piece holders, pulley/pointer arrangement with at least ×5 magnification of movement.
- Temperature sensor graduated to 1 °C and accurate to ±0.5 °C; heater capable of 2 °C/min ±0.2 °C/min heating rate.
- Distilled/de‑ionized water grade 3 (ISO 3696) and a stirrer to keep top/bottom temperature difference ≤1 °C.
- Desiccator and vacuum pump able to reach absolute pressure <4 kPa.
- Sample preparation: Rectangular pieces (typically 50 mm × either 3.0 mm or 2.0 mm depending on thickness); samples taken parallel and perpendicular to backbone per ISO 2418.
- Procedure highlights:
- Optional pre‑wetting under vacuum (for dry samples) using ~5.5 ml water in a small tube.
- Mount sample under light tension (mass 3 g heavier than movable holder).
- Heat water at controlled rate (2 °C/min); record pointer position and temperature at 30 s intervals.
- Determine shrinkage temperature as the temperature corresponding to a pointer movement equal to a 0.3% shrinkage.
- Reporting requirements: Reference ISO 3380, mean shrinkage temperature in each direction (or stated as > final temp reached), any method deviations, and sample identification details.
Practical applications and users
- Who uses it: tanneries, material testing laboratories, quality control teams, R&D departments, certification bodies, and manufacturers of leather testing equipment.
- Why it’s used: to evaluate thermal stability of leather (indicator of tanning effectiveness and collagen integrity), to support product acceptance criteria, failure analysis, and comparative R&D of tanning processes and finishes.
Related standards
- ISO 2418 - Sampling location for leather
- ISO 2589 - Thickness measurement
- ISO 3696 - Water for analytical laboratory use
EN ISO 3380:2015 provides a repeatable, internationally recognized method for determining leather shrinkage temperature - a key parameter for leather quality, processing decisions, and conformity testing.