Overview
SIST EN ISO 2556:2001 defines a standardized method for determining the gas transmission rate (GTR) of plastic films and thin sheets under atmospheric pressure using a manometric technique. This international standard, identical to EN ISO 2556:2000 and originally based on ISO 2556:1974, is essential for assessing polymer material performance in applications sensitive to gas permeability. The procedure involves using a plastic specimen to separate two chambers, measuring the quantity of gas passing through the specimen as a function of time by monitoring pressure changes in an evacuated chamber with a manometer.
Key Topics
- Gas Transmission Rate Measurement: The standard specifies how to determine the volume of gas that, under steady-state conditions, permeates a unit area of a plastic film or sheet within a set period, at a defined pressure difference and temperature.
- Test Apparatus: Two types of suitable test equipment are outlined for reliable results. The apparatus must maintain temperature stability and ensure accurate measurement of pressure changes.
- Sample Preparation: Clear criteria are set for the characteristics and conditioning of test specimens to ensure consistent and statistically sound measurement outcomes.
- Data Expression and Reporting: The results are typically reported in cm³/(m²·d·atm), and guidelines are given for calculating, correcting, and documenting measured transmission rates.
Applications
- Packaging Industry: Quality control and material development for food, pharmaceutical, and cosmetic packaging rely heavily on this standard to ensure barrier properties against oxygen, carbon dioxide, and other gases.
- Polymer Film Manufacturing: Material selection, formulation optimization, and comparative analysis of different plastic films and thin sheets are facilitated by standardized GTR data.
- Quality Assurance and Compliance: Regulatory and contractual requirements often reference this standard for verifying product properties during routine testing or incoming goods inspection.
- Research and Development: The method supports R&D activities focused on creating new plastics with customized gas permeability for various end uses.
Related Standards
- ISO/R 291: Plastics - Standard atmospheres for conditioning and testing, referenced for determining sample preparation and testing environments.
- SIST EN ISO 2556:2001 serves as the Slovenian adoption of EN ISO 2556:2000, unifying international testing requirements.
- Other ISO 2556 Versions: Variations of this standard may exist, and users should ensure alignment with the version specified in their regulatory or contractual context.
Keywords: plastics, gas transmission rate, films, thin sheets, manometric method, permeability, standardized testing, atmospheric pressure, quality control, packaging materials
By following the consistent procedures outlined in SIST EN ISO 2556:2001, organizations can reliably measure the gas permeability of plastics, facilitating material innovation, quality assurance, and regulatory compliance in a range of critical industries.
