Barrier and permeation
Polypedia > Properties of polymers > Physical properties
Barrier or permeation | |
The measurement of barrier or permeation properties of polymers and plastics is essential in a wide range of industries including packaging, medical products, cosmetics or food where manufacturers and end users require information on the barrier properties of a material. Polymers and plastics are permeable and their barrier properties can affect their suitability for a specific application. In packaging, for example, ineffective barrier properties can make the closed product vulnerable to surrounding environmental factors, such as water, moisture and oxygen, including future storage. The barrier properties may be affected by the processing parameters during production, but may also be affected by the environmental temperatures associated with their final use. At high temperatures, a greater permeation of liquids or vapors results in the plasticization of the polymer and the mechanical properties of the material are degraded, which increases the permeability. | |
Water vapor transmission rate (WVTR) | |
The barrier properties by measuring the gas transmission rate, which is the amount of gas that can pass through a specific area of the plastic material over time. The main gases that affect the shelf life and stability of the package of most products are oxygen and water vapor, so we offer the water vapor transmission rate (WVTR) through the methods established by ASTM D1653 industry, the water vapor transmission of organic coating films and the ASTM E96 water vapor transmission of materials. We can also perform tests on ASTM F1249, Standard test method for the water vapor transmission rate through plastic film and sheets using a modulated infrared sensor and ISO 15106-2, Plastics - Film and foils - Determination of the rate of water vapor transmission. | |
Oxygen transmission rate (OTR) | |
The is an important determinant of the protection of the packaging offered by the barrier materials, in particular for films, sheets, laminates, coextrusions or plastic coated papers. We measured the OTR through ASTM D3985, oxygen permeation of flexible barrier materials using an ASTM D3985, ISO 15105 coulometric sensor to determine the permeability coefficient, permeability and transmission rates. |