ISO 3380:2015

Overview

ISO 3380:2015 - Leather - Physical and mechanical tests - Determination of shrinkage temperature up to 100 °C - specifies a standardized laboratory method to determine the shrinkage temperature of leather (up to 100 °C). Prepared by IULTCS in cooperation with CEN, the method is applicable to all leathers and is used to assess thermal stability related to collagen denaturation.

Key topics and technical requirements

• Scope: Determination of the temperature at which a leather specimen undergoes sudden shrinkage when heated in water (up to 100 °C).
• Principle: Heat a suspended test piece in water at a controlled rate and record the temperature at which a measurable shrinkage occurs.
• Apparatus essentials:
  • Vessel (≥ 500 ml, working depth ≥ 110 mm) and heater capable of a controlled heating rate.
  • Fixed and moveable test-piece holders, pulley and pointer system with at least 5× magnification of movement.
  • Temperature sensor accurate to ±0.5 °C, graduated to 1 °C.
  • Stirrer to keep temperature uniform (top-to-bottom difference ≤ 1 °C).
  • Optional pressurized vessel for testing above 100 °C.
• Sample preparation:
  • Sampling per ISO 2418; thickness measured per ISO 2589.
  • Test-piece dimensions: typically 50 mm × 3.0 mm (≤ 3 mm thick) or 50 mm × 2.0 mm (> 3 mm thick); orientation: two samples parallel and two perpendicular to backbone.
• Procedure highlights:
  • For dry samples: pre-immerse in 5.5 ml water in a sealed tube, evacuate desiccator to < 4 kPa, then re-immerse 1–6 h.
  • Heat water at (2 ± 0.2) °C/min; record pointer position and temperature every 30 s.
  • Shrinkage temperature = temperature when pointer movement equals 0.3% shrinkage from maximum length.
• Reporting: Reference ISO 3380, mean shrinkage temperature in each direction, any deviations, and full sample identification.

Applications and users

• Practical for quality control, R&D, and certification in the leather industry.
• Used by leather tanneries, testing laboratories, material scientists, product manufacturers (footwear, upholstery, garments), and regulatory bodies to:
  • Assess collagen thermal stability and leather durability.
  • Compare tanning processes and heat treatments.
  • Verify supplier or batch conformity to specified thermal performance.

Related standards

• ISO 2418 - Sampling location for leather tests
• ISO 2589 - Determination of leather thickness
• ISO 3696 - Water for analytical laboratory use

Keywords: ISO 3380:2015, shrinkage temperature, leather testing, leather standards, physical and mechanical tests, IULTCS, leather quality control.