Overview
ISO 15105-1:2007 - Plastics - Film and sheeting - Determination of gas‑transmission rate - Part 1: Differential‑pressure methods specifies two standardized laboratory methods to measure the gas transmission rate (GTR) of single‑layer and multi‑layer plastic films and sheets under a differential pressure. One method uses a pressure sensor to monitor pressure rise on the low‑pressure side; the other uses gas chromatography to quantify the permeating gas. Results are used to calculate GTR and the gas permeability coefficient.
Key topics and requirements
- Two differential‑pressure methods:
- Pressure sensor method (Annex A) - measures pressure increase on the low‑pressure chamber.
- Gas chromatography method (Annex B) - chemically analyses permeated gas.
- Test specimens: representative, free of defects, larger than the transmission area. Use three specimens unless otherwise agreed; mark gas‑facing side.
- Thickness measurement: follow ISO 4593, measure at ≥5 points and record min/max/average (to nearest 1 µm).
- Conditioning and test conditions: dry specimens for not less than 48 h when required; standard test room temperature 23 °C ± 2 °C (unless otherwise specified).
- Apparatus essentials (pressure sensor method): gas transmission cell with constant test area (diameter 10–150 mm), pressure sensor with sensitivity ≥ 5 Pa, vacuum pump capable of < 10 Pa, gas feeder/reservoir, and cell volume control.
- Gas quality: preferentially purity > 99.5%; composition, pressure and purity must be recorded.
- Calculation and units: GTR is calculated from the pressure‑change rate and cell parameters; commonly reported in mol/(m·s·Pa) or converted to cm³/(m²·24 h·atm). Report the arithmetic mean of specimens, rounded to three significant figures.
- Test report requirements: method used, apparatus details, specimen identification and preparation, thickness, conditioning, test temperature/humidity, gas details, results and test date.
Practical applications and users
ISO 15105-1 is widely used in industries and laboratories concerned with barrier properties of plastic films and sheets:
- Food, pharmaceutical and medical packaging manufacturers assessing oxygen or other gas barrier performance
- Packaging designers and material developers selecting films or multilayer structures
- Quality control and R&D laboratories validating permeability for shelf‑life and barrier claims
- Certification bodies and suppliers providing material datasheets or compliance evidence
This standard supports decisions on material selection, package design, barrier optimization and regulatory or customer requirements for controlled atmospheres.
Related standards
- ISO 15105-2 - Plastics - Film and sheeting - Determination of gas‑transmission rate: Equal‑pressure method (companion part)
- ISO 4593 - Plastics - Film and sheeting - Determination of thickness by mechanical scanning
- ISO 291 (environmental conditions) - where alternative conditioning or test environments are agreed
Keywords: ISO 15105-1, gas transmission rate, GTR, plastics film sheeting, differential-pressure methods, permeability testing, pressure sensor, gas chromatograph.