Barrier and Permeation Properties of Polymers and Plastics

Measurement of barrier or permeation properties of polymers and plastics is essential across a wide range of industries including packaging, medical, cosmetics or food where manufacturers and end-users require information regarding a material’s barrier properties.

Polymers and plastics are permeable and their barrier properties may impact their suitability for a specific application. In packaging, for example, ineffective barrier properties may render the enclosed product vulnerable to surrounding environmental factors, such as water, humidity, and oxygen, including its future storage.

Barrier properties can be affected by processing parameters during production but can also be affected by ambient temperatures associated with its end-use. In high temperatures greater permeation of liquids or vapours result in polymer plasticization and the mechanical properties of the material become degraded leading to increases permeability. 

Our polymer scientists assess barrier properties by measurement of transmission rate for gases which is the quantity of gas that is able to pass through a specific area of the plastic material over time.  The main gases that affect the shelf life and packaged stability of most products are oxygen and water vapour and so we provide Water Vapor Transmission Rate (WVTR) via industry established methods ASTM D1653, Water Vapor Transmission of Organic Coating Films and ASTM E96 Water Vapor Transmission of Materials. We can also provide testing to ASTM F1249, Standard Test Method for Water Vapor Transmission Rate Through Plastic Film and Sheeting Using a Modulated Infrared Sensor and ISO 15106-2, Plastics - Film and sheeting - Determination of water vapour transmission rate. 

The Oxygen Transmission Rate (OTR) is an important determinant of the packaging protection afforded by barrier materials particularly for film, sheeting, laminates, coextrusions, or plastic-coated papers. We measure the OTR via ASTM D3985, Oxygen Permeation of Flexible Barrier Materials Using a Coulometric Sensor ASTM D3985, ISO 15105 to determine the permeability coefficient, permeance and transmission rates. 

We are able to provide customized tests developed to suit your application including how other gases and vapours  - such as H2, CH4, O2, N2, Ar, CO2 and H2O - move across a material. 

We apply these methods to your samples or products appropriately whether they are films of organic coatings or plastic sheeting. The data we generate can support your product development, manufacture, and marketing. Supporting your product development, our experts can help you to understand how permeability can be impacted by processing parameters, and also assess how variations in material characteristics, morphology, orientation, crystallinity, thickness, humidity, temperature, surface characteristics, thin layer coatings, additives and multilayer functionality may all influence barrier properties.

We will provide insight into adsorption, dissolution, diffusion, and desorption of materials to maximize preservation effect, as well as providing guidance into the right choice of material, considering the specific end-use, nature of the product as well as variables such as storage and transport.

Our barrier property experts are on hand to discuss your requirements and to deliver rigorously-tested barrier and permeation solutions specific to your needs. Our polymer physical and mechanical testing services are a one-source solution that can support large research and design projects, quality control, research and development, problem-solving, failure analysis for advanced materials and products.

Further understanding of barrier properties is facilitated by Intertek through assessment of material characteristics such as orientation, crystallinity, surface characteristics, additives and multilayer functionality.

Case Study: Evaluating the Barrier Properties of a Membrane