How UL 94 and ASTM E84 Testing Methods Vary?

 

UL 94 is a test method developed by Underwriters Laboratories in the U.S., mainly used for evaluating the flame retardancy of plastic materials.UL 94 test object is a sample of plastic materials, which is classified into a number of grades according to the combustion characteristics of the sample, including V-0, V-1, V-2, HB, 5VB and 5VA.V-0 grade is the best fire performance, and 5VA grade is the best fire performance, and 5VA grade is the best fire performance. 0 rating is the best fire resistance, and the 5VA rating is the least fire resistant.

 

ASTM E84 is a test method developed by ASTM International, also known as the Standard Test Method for Surface Burning Characteristics of Building Materials. ASTM E84 is primarily used to evaluate the flame propagation characteristics of building materials such as wallboard, flooring, and ceilings. The test method categorizes a material's burning performance into two indices: the Flame Spread Index (FSI) and the Smoke Developed Index (SDI); the lower the FSI and SDI values, the better the material's resistance to fire.

 

These two test methods have different rating scales and applicability, but both assess the performance of the material under fire conditions. In selecting the appropriate test method, the choice should be based on the characteristics of the specific material and the performance to be evaluated.

 

 

1. different test devices: UL 94 test along the vertical axis of the suspended specimens, while the ASTM E84 is placed along the horizontal axis of the dimensions of 25 ft × 20 ft × 12 ft (length × width × height) of the combustion chamber.

 

2. Different ignition methods: UL 94 tests include small ignition source and large ignition source combustion tests, both for single-point ignition. ASTM E84 is a diffusion fire test, which simulates the fire conditions in the actual environment. 3.

 

3. Different evaluation dimensions: UL 94 focuses on the self-extinguishing properties of the material and the amount of residue left after burning, while ASTM E84 focuses on the spreading speed of the flame and the amount of smoke generated when the material burns.

 

It should be noted that UL 94 and ASTM E84 are both standardized test methods, and the test results are useful for evaluating a material's fire resistance, but they do not fully represent the fire conditions in an actual environment. Factors such as how the material is used and the environment will also affect its fire performance. If a more comprehensive assessment is required, further verification through actual testing or simulation is recommended.