ISO 15105-1 - Plastics Film and sheeting - Determination of gas-transmission rate - Part 1: Differential-pressure methods

ISO 15105-1

Plastics — Film and sheeting — Determination of gas-transmission rate — Part 1: Differential-pressure methods

ISO 15105-1:2007 specifies two methods for determining the gas transmission rate of single-layer plastic film or sheet and multi-layer structures under a differential pressure. One method uses a pressure sensor, the other a gas chromatograph, to measure the amount of gas which permeates through a test specimen.

What is ISO 15105-1?

ISO 15105-1 is an international standard that outlines methods for determining the gas transmission rate (GTR) of plastic films and sheeting. This standard is part of the larger ISO 15105 series, which addresses the permeability of flexible barrier materials to gases. Specifically, ISO 15105-1 focuses on the differential-pressure method for measuring the rate at which gases pass through a plastic barrier. This is crucial in industries like food packaging, where controlling gas permeability is essential for maintaining product freshness and quality.

Test Standard for Determination of Gas Transmission Rate

The gas transmission rate (GTR) is a key parameter in evaluating the performance of barrier materials, such as plastic films, in preventing the passage of gases like oxygen, nitrogen, carbon dioxide, and others. ISO 15105-1 provides a standardized framework for testing this parameter using the differential-pressure method. This involves measuring the amount of gas that passes through a test sample under controlled temperature and pressure conditions. The test is important for assessing the suitability of packaging materials, especially in industries where the product’s shelf life is influenced by the ingress or egress of gases.

ISO 15105-1 Test Process

The ISO 15105-1 test process begins by preparing a sample of the plastic film or sheet to be tested. The sample is mounted between two chambers: one filled with the test gas at a higher pressure, and the other at a lower or near-vacuum pressure. As gas diffuses through the material, the pressure difference across the sample drives the transmission process. The amount of gas passing through the film is then measured over time, and the gas transmission rate is calculated. The testing conditions, such as temperature and humidity, must be carefully controlled as they can significantly affect the material’s permeability.

The test provides quantitative data on the barrier properties of the material, allowing manufacturers to determine whether a given plastic film or sheeting is suitable for specific applications, particularly where gas barrier properties are critical, such as in food, pharmaceuticals, and other sensitive products.