What does flammability UL94 mean?
2020-11-17 10:14
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UL is the shortcut for Underwriters Laboratories. This is an independent organisation in the United States to control and certificate product safety. Beside a lot of product standards UL also specified the flammability test UL94 for plastic materials. UL94 is a material burning test done on a defined specimen of the raw material but not a test on final products. UL94 differs between a horizontal burning test UL94 HB (picture 1) and a vertical burning test UL94 V (picture 2). For the vertical test UL94 V there are three flame ratings defined: UL94 V0, UL94 V1 and UL94 V2.
In all these burning tests an open flame is applied for a certain time to the specimen. As the burning behaviour also depends on the thickness of the material it is important to classify the material not only according to HB, V0, V1 or V2 but also to mention the thickness of specimen.
