ASTM F1927 - Standard Test Method for Determination of Oxygen Gas Transmission Rate, Permeability and Permeance at Controlled Relative Humidity Through Barrier Materials Using a Coulometric Detector:
The ASTM F1927 standard is a testing methodology that determines the oxygen gas transmission rate, permeability, and permeance of various materials at controlled relative humidity (RH) levels. The method uses a Coulometric detector, a device that quantitatively measures the amount of substance through the electrical charge needed to convert a substance from one oxidation state, ion, or molecule to another.
The measurement of oxygen gas transmission rate (O2GTR) is essential in evaluating the barrier properties of packaging materials. It is critical for maintaining product quality and ensuring the longevity of packed goods, particularly in the food and pharmaceutical industries.
The materials tested under the ASTM F1927 standard can include film, sheeting, laminates, co-extrusions, or plastic-coated papers or fabrics. The method involves keeping the test material at a steady-state temperature and relative humidity level, after which the oxygen gas transmission rate is measured. This improves upon previous testing methods that either did not account for humidity or made assumptions about humidity levels.
The procedure also allows for the determination of the permeance of the film to oxygen gas (PO2), the permeation coefficient of the film to its thickness (P"O2), and oxygen permeability coefficient (PʹO2) in the case of homogeneous materials. These parameters provide additional information about the material's permeability characteristics and can help in the evaluation and selection of packaging materials.
The O2GTR measured under specific temperature and relative humidity conditions provides important information about the protection capacity of packaging materials. However, it is not the sole determinant of the material's protective quality, and other tests should be conducted to give a comprehensive overview of the material's performance.
The standard can serve as a referee method of testing, provided that the purchaser and seller have agreed on sampling procedures, standardization procedures, test conditions, and acceptance criteria. This ensures that the results obtained are reliable and can be used to compare the performance of different materials.