Overview
EN ISO 1110:2019 - Plastics - Polyamides - Accelerated conditioning of test specimens specifies a validated method for accelerated conditioning of polyamide (PA) and copolyamide test specimens prior to mechanical or physical testing. The method is intended to produce an equilibrium moisture content close to that obtained in standard atmosphere 23 °C / 50 % RH, but in a much shorter time. It applies to grades containing fillers and additives, excluding grades with more than 2 % mass fraction of extractables.
Keywords: EN ISO 1110:2019, polyamides, accelerated conditioning, test specimens, equilibrium moisture content.
Key topics and technical requirements
- Scope and applicability: Applies to polyamides and copolyamides (including filled grades) except those with >2 % extractables. Results may differ slightly from standard atmosphere conditioning.
- Principle: Specimens are conditioned at an elevated temperature and controlled humidity until moisture uptake reaches at least 95 % of equilibrium.
- Conditioning environment:
- Preferred: a cabinet with closed air circulation, maintained at 70 °C ± 1 °C and a psychrometric temperature difference of 10 °C ± 0.3 °C (≈ 62 % RH ± 1 %).
- Alternative: oven at 70 °C with specimens placed in a closed container partially filled with a saturated aqueous potassium iodide solution (per ISO 483) to maintain humidity.
- Monitoring and acceptance:
- Use an analytical balance accurate to 0.1 mg.
- Remove specimens after specified conditioning intervals, cool in standard atmosphere 23 °C / 50 % RH, and weigh.
- Conditioning is complete when three consecutive weighings are within 0.1 % of each other.
- Minimum interval periods and detailed times depend on PA type and specimen thickness - consult Table 1 of EN ISO 1110:2019 for group-specific durations.
- Reference method: In case of dispute, use the cabinet procedure (closed-circulation cabinet).
Applications and users
- Quality control laboratories performing mechanical, thermal or dimensional testing of polyamides.
- Material suppliers and polymer manufacturers establishing data sheets and batch qualification.
- R&D teams studying moisture-sensitive properties of PA (toughness, tensile strength, dimensional stability).
- OEMs and test houses requiring reproducible conditioning prior to compliance testing or comparative evaluations.
Practical value: accelerated conditioning shortens test lead times (vs. prolonged room-temperature conditioning) while producing moisture contents representative of standard 23 °C / 50 % RH, enabling faster validation cycles and consistent, reproducible test data.
Related standards
- ISO 291 - Standard atmospheres for conditioning and testing (reference atmosphere 23 °C / 50 % RH).
- ISO 483 - Conditioning enclosures using aqueous solutions to maintain constant humidity (used for the alternative container method).
For accurate implementation, consult the full text of EN ISO 1110:2019 and associated tables specifying conditioning durations by polyamide group and specimen thickness.