Do you know what is the UL 94 Standard of testing?

 

The UL 94 standard evaluates the flame retardancy level of materials by placing plastic samples in contact with open flames or combustion sources and observing their combustion characteristics and ability to catch fire. The main evaluation indicators include flame delay time, self-extinguishing time, drip formation and flame spread during combustion, etc.

During testing, material samples are cut to specific shapes and sizes and pretreated to remove surface contamination. The samples are then held in a vertical combustion stand and an ignition source or open flame is used to expose the material. During the test, the burning behavior of the material is observed, including the spread of the flame, whether drips are produced, and the time for the flame to self-extinguish.

 

 

1. V-0 rating: The material shall not stop burning under flame exposure for more than 10 seconds, shall not produce drips, and the flame shall self-extinguish after the designated ignition source is removed.

 

2. V-1 grade: The time for the material to stop burning under flame exposure should not exceed 30 seconds, should not produce sustained burning, and the number of drippings and burning time should be limited.

 

3. V-2 level: The time for the material to stop burning under flame exposure should not exceed 30 seconds, should not produce sustained burning, and the number of drippings and burning time should be limited.

 

In addition to these grades, there are some supplementary grades, such as HB grade, 5VA grade and 5VB grade, which are used to evaluate the specific flame retardancy properties of materials.

 

The use of the UL 94 standard helps to ensure that the plastic materials used are highly flame retardant, thereby reducing the risk of fire. It is widely used in electronic and electrical equipment, auto parts, construction materials, etc. In addition, other countries and regions also use similar testing standards to evaluate the flame retardancy of materials, and the UL 94 standard has a certain influence and recognition internationally.