ISO 15106-5:2015

Overview

ISO 15106-5:2015 - titled "Plastics - Film and sheeting - Determination of water vapour transmission rate - Part 5: Pressure sensor method" - specifies a laboratory method for measuring the water vapour transmission rate (WVTR) of plastic film, plastic sheeting, and multi‑layer structures using a pressure sensor. The method provides relatively rapid WVTR measurement across a wide range of permeability values by detecting pressure increase on the downstream side as water vapour permeates through the specimen.

Key topics and technical requirements

• Principle: A specimen seals two chambers (upstream and downstream). The upstream is filled with controlled water vapour; permeation is measured as pressure rise in the downstream chamber.
• Apparatus components:
  • Transmission cell with constant transmission area (typical diameter 5–200 mm).
  • Pressure sensor for downstream chamber (recommended sensitivity ~0.2 Pa).
  • Water vapour generator with reservoir pressure sensor (min. sensitivity ~20 Pa).
  • Cell volume‑control device (to extend measurement range) and vacuum pump (ultimate vacuum ≤ 1 Pa).
• Specimens & conditioning:
  • Representative, defect‑free specimens; larger than the transmission area.
  • Typical testing of three specimens unless agreed otherwise.
  • Conditioning to the chosen test temperature and humidity prior to testing.
• Test conditions: Standard selectable conditions include 25, 40, 60 °C (all at 90% RH) and 85 °C at 85% RH (± specified tolerances).
• Procedure: Evacuate chambers, introduce water vapour upstream, record downstream pressure vs. time, determine steady‑state slope (dp/dt).
• Calculation: WVTR is calculated from downstream volume, transmission area, temperature and measured dp/dt (formula in clause 10).
• Quality controls: Background measurement (cell without sample) recommended; report must include apparatus, sample details, area, thickness, conditioning, and mean result.
• Precision: Interlaboratory precision not yet established (no precision statement in this edition).

Applications and users

ISO 15106-5 is applicable wherever accurate WVTR/WV permeability data are needed for plastic films and multilayer laminates. Typical users include:

• Packaging engineers assessing moisture barrier for food, pharmaceuticals, electronics.
• Materials scientists and R&D teams developing barrier films and coatings.
• Quality control and test laboratories performing standardized WVTR certification.
• Suppliers specifying barrier performance for multi‑layer structures.

Benefits include rapid measurement capability and suitability for a wide WVTR range; important when comparing barrier performance or validating new materials.

Related standards

• ISO 15106 series (other detection methods): Part 1 (humidity sensor), Part 2 (infrared), Part 3 (electrolytic), Part 4 (gas‑chromatographic), Part 6 (atmospheric pressure ionization MS), Part 7 (calcium corrosion).
• ISO 4593:1993 (thickness determination of films and sheeting) is referenced in the bibliography.