Overview
EN ISO 4590:2016 / ISO 4590:2016 specifies a standardized laboratory procedure for determining the volume percentage of open cells and closed cells in rigid cellular plastics (rigid foams). The standard defines how to measure the specimen surface area and geometrical volume, and how to determine the impenetrable volume (Vi) by controlled gas methods. Results are corrected for surface cells opened during specimen preparation and reported as apparent and corrected open/closed‑cell percentages.
Key Topics
- Scope and purpose: General procedure to quantify open‑cell and closed‑cell volume fractions in rigid cellular plastics for material characterization and quality control.
- Measurement principles:
- Determination of surface area (S) and geometrical volume (Vg) from specimen dimensions.
- Measurement of impenetrable volume (Vi) using gas laws (Boyle–Mariotte principle).
- Methods for Vi:
- Method 1 - Pressure variation (pyknometer): measures pressure changes with and without specimen in an indeformable chamber.
- Method 2 - Volume expansion: includes method 2a (existing apparatus) and the new method 2b (updated apparatus reflecting modern equipment).
- Specimen preparation and testing:
- Minimum of three test specimens; three tests per specimen.
- Requirements for conditioning, dimensions, and sectioning to account for cells opened by cutting.
- Data treatment:
- Calculate apparent open‑cell volume ω as a function of the specimen surface/volume ratio r.
- Extrapolate ω(r) to r = 0 to obtain the corrected open‑cell percentage (ω0) and the corrected closed‑cell percentage (ψ0).
- Quality and reporting: Includes calibration, precision information, and a defined test report format.
Applications and Users
- Who uses this standard:
- Materials test laboratories conducting foam characterization.
- Foam manufacturers for product development and quality assurance.
- Product specifiers and compliance engineers assessing thermal insulation, acoustic, buoyancy or structural performance influenced by cell openness.
- Regulatory bodies and procurement teams requiring standardized material data.
- Practical applications:
- Comparing materials (rigid PU, PF, PIR, phenolic and other rigid cellular plastics) by open/closed cell content.
- Correlating cell structure with properties such as thermal conductivity, moisture uptake, mechanical behavior, and flame performance.
- Ensuring batch consistency and meeting product specifications.
Related Standards
- ISO 1923 - Cellular plastics and rubbers: determination of linear dimensions (referenced normative standard).
- EN ISO 4590:2016 supersedes EN ISO 4590:2003 (CEN endorsement).
Keywords: EN ISO 4590:2016, ISO 4590:2016, rigid cellular plastics, open cells, closed cells, impenetrable volume, pyknometer, volume expansion, method 2b, surface/volume ratio, foam testing.
