How does the oxygen index test compare to the UL 94 test and the ASTM D635 test?

The oxygen index test measures the minimum concentration of oxygen in a mixture of oxygen and nitrogen that is needed to support combustion of a plastic material. This test is used to determine the material's resistance to burning and is often used for materials that are intended for use in high-risk applications, such as aircraft interiors.

 

The UL 94 test is a standardized test method used to evaluate the flammability of plastic materials used in electrical devices and appliances. The test involves exposing a sample of the material to a small flame and observing its behavior. The UL 94 test assigns a classification rating to the material based on its performance in the test, with ratings ranging from V-0 (highest rating) to HB (lowest rating).

The ASTM D635 test is a test method used to evaluate the burning behavior of plastics when exposed to a radiant heat source. The test involves exposing a sample of the material to a radiant heat source and observing its behavior. The test measures the time it takes for the material to self-extinguish and assigns a classification rating based on its performance in the test.

 

Overall, each of these test methods provides valuable information about the flammability characteristics of plastic materials, but they are designed for different applications and may provide different types of information. It is important to carefully consider the requirements of a specific application when selecting a test method for evaluating the flammability of plastic materials.