ISO 2440:2019

Overview

ISO 2440:2019 specifies laboratory procedures for accelerated ageing tests of flexible and rigid cellular polymeric materials. The standard defines controlled dry-heat and humidity (steam) treatments that simulate chemical ageing mechanisms such as oxidation and hydrolysis, and it requires measurement of selected physical properties before and after exposure. Test conditions are provided for open-cell latex, open- and closed-cell polyurethane foams, and closed-cell polyolefin foams; additional materials are to be added as needed.

Key topics and technical requirements

• Materials covered: open-cell latex, open- and closed-cell polyurethane foams, closed-cell polyolefin foams; composite constructions containing these materials also permitted.
• Ageing modes:
  • Dry heat (forced‑circulation oven, temperature control ±3 °C).
  • Humidity/steam (100% RH or saturated steam using autoclave or sealed vessel; apparatus sizing to ensure specimens ≤10% of chamber free volume).
• Typical test temperatures (selected):
  • Polyolefin: 70 °C (dry heat)
  • Latex: 70 °C or 100 °C (dry heat)
  • Polyurethane (dry heat): 80 °C, 125 °C or 140 °C
  • Polyurethane (humidity/steam): 85 °C for 20 h or 105 °C for 3 h; polyether polyurethane: 120 °C for 5 h
• Duration options (dry heat): 16 h, 22 h, 72 h, 96 h, 168 h, 240 h, or multiples of 168 h (±5% tolerance, not exceeding ±4 h). Humidity durations have specified tolerances.
• Specimen conditioning: minimum time after manufacture and pre-test conditioning per ISO 23529 (e.g., 23 °C ±2 °C, 50% ±5% RH or 27 °C ±2 °C, 65% ±5% RH).
• Post-ageing reconditioning: specimens aged in humidity must be dried (70 °C ±3 °C for 3 h per 25 mm thickness, min 3 h) then reconditioned before measurement.
• Measured properties: elongation/tensile or compression/indentation hardness are typical; any physical property may be examined. Results should report average values before/after and percentage change (presented with time, temperature, method).

Applications and typical users

• Who uses it: materials laboratories, foam manufacturers, R&D teams, quality assurance, product designers, test houses assessing foam durability and hydrolytic or oxidative resistance.
• Practical uses:
  • Accelerated screening of foam formulations and stabilizers.
  • Comparative performance testing across suppliers or batches.
  • Investigating interactions in composite constructions (foam bonded to substrates).
  • Quality control and specification verification where in-service ageing mechanisms are chemical (not light exposure).
• Limitations: the standard notes that accelerated ageing under these conditions does not necessarily correlate with in‑service behaviour or ageing from light (UV).

Related standards

• ISO 23529 - referenced for specimen preparation and conditioning procedures.

Keywords: ISO 2440:2019, accelerated ageing tests, cellular polymeric materials, polyurethane foam testing, polyolefin foam, latex foam, dry heat ageing, hydrolysis testing, foam durability.