Overview
EN ISO 11357-3:2025 - Plastics - Differential scanning calorimetry (DSC) - Part 3: Determination of temperature and enthalpy of melting and crystallization (ISO 11357-3:2025) defines a standard method for measuring melting and crystallization temperatures and their enthalpies in crystalline or partially crystalline plastics using conventional DSC. The document is a 2025 revision, endorsed by CEN as EN ISO 11357-3:2025, and supersedes the 2018 edition. It explicitly excludes fast DSC methods (see ISO 23976).
Key topics and requirements
The standard sets out the full experimental framework needed for reliable DSC thermal data:
- Scope & principle - objective and limits (conventional DSC for plastics; not for fast DSC).
- Apparatus and materials - requirements for DSC instruments and consumables.
- Test specimen - sampling, dimensions and conditioning to ensure representative results.
- Test conditions & specimen conditioning - recommended scan rates and thermal pre-treatment (see standard for specific conditions).
- Calibration - temperature and enthalpy calibration procedures to ensure traceable results.
- Procedure - stepwise instructions including setting up the instrument, loading crucibles, insertion, and performing the temperature scan.
- Expression of results - calculation and reporting of transition temperatures and enthalpies (melting/crystallization).
- Precision - expected reproducibility and repeatability guidance.
- Test report - required information to accompany results for traceability and conformity.
(Each of the above topics is covered in dedicated clauses in ISO 11357-3:2025.)
Practical applications
EN ISO 11357-3:2025 is used wherever accurate thermal characterization of semi‑crystalline plastics is required:
- Quality control and acceptance testing of polymer lots and finished parts.
- R&D and formulation development to evaluate crystalline content and melting behavior.
- Process optimization for extrusion, injection molding and thermoforming by defining melting/crystallization ranges.
- Comparative testing of additives, nucleating agents, fillers and recycled feedstocks.
- Certification, material declarations and failure analysis requiring standardized thermal data.
Who should use this standard
- Polymer scientists, materials engineers and laboratory technicians performing DSC on plastics.
- QC/QA laboratories in polymer manufacturing, converters and compounders.
- Third‑party testing and certification bodies, research institutes and academic labs.
- Equipment manufacturers and service providers offering DSC testing (conventional DSC).
Related standards & keywords
- Related: ISO 11357‑1 (general DSC) and ISO 23976 (fast DSC - excluded here).
- Keywords for search optimization: EN ISO 11357-3:2025, ISO 11357-3:2025, differential scanning calorimetry, DSC, melting temperature, crystallization temperature, enthalpy of fusion, plastics thermal analysis, conventional DSC, polymer testing, DSC calibration.
