ASTM D2863 is a standard test method established by the American Society for Testing and Materials (ASTM) that is used to measure the minimum oxygen concentration required to support combustion in a flowing mixture of oxygen and nitrogen. This measurement is known as the limiting oxygen index (LOI).
The ASTM D2863 standard test method provides a quantitative assessment of the flammability characteristics of polymers, particularly those used in electrical and electronic applications. The LOI is an indicator of the polymer's ability to resist ignition and self-extinguish when exposed to a flame. It is an important parameter for evaluating the fire safety performance of materials.
The test procedure involves exposing a vertically oriented specimen to a mixture of oxygen and nitrogen. The oxygen concentration is gradually decreased until the specimen self-extinguishes. The LOI is then determined as the percentage of oxygen required to sustain combustion relative to the total oxygen and nitrogen flow rate.
The ASTM D2863 standard outlines specific requirements for the size and preparation of test specimens, as well as the apparatus and testing conditions. The standard provides different options for the flow rate and temperature of the gas mixture, allowing flexibility for different applications and materials.
The LOI value obtained from the ASTM D2863 test can provide valuable information for material selection, process optimization, and product development. Higher LOI values generally indicate better flame resistance and lower flammability. It is important to note that the LOI alone does not provide a complete assessment of a material's fire performance, as other factors such as smoke development and heat release are also relevant.
The ASTM D2863 standard is widely used in various industries, including automotive, aerospace, construction, and electronics, where fire safety is a critical consideration. Engineers, researchers, manufacturers, and regulatory bodies use the LOI values obtained from this test to compare different materials, develop fire-resistant formulations, and ensure compliance with safety standards and regulations.
It is important to consult the latest version of the ASTM D2863 standard for specific details and requirements, as standards are periodically updated to reflect advancements in testing methodologies and new research findings. The standard can be obtained from the ASTM International website or through other authorized channels.
In summary, ASTM D2863 is a widely accepted standard test method that quantifies the flammability characteristics of polymers by measuring the limiting oxygen index. This parameter plays a crucial role in assessing the fire safety performance of materials and is used in various industries to make informed decisions regarding material selection and product development.