UL 94 is a flammability standard published by Underwriters Laboratories (UL) that evaluates the flammability characteristics of plastic materials. The standard classifies materials into different ratings, such as V-0 and V-1, based on their resistance to ignition and burning behavior.
V-0 and V-1 are two different ratings within UL 94, representing different levels of flame retardancy. Here is the difference between them:
1. V-0 rating: A material with a V-0 rating is considered the highest level of flame retardancy. To meet this rating, the material must extinguish the flame within ten seconds of removal of the ignition source and should not have any flaming drips. Additionally, the material should not show any glow or continued combustion for more than thirty seconds.
2. V-1 rating: A material with a V-1 rating is also flame retardant but has slightly less stringent requirements compared to V-0. A V-1 material must self-extinguish the flame within ten seconds of ignition and should not have any flaming drips. However, it is allowed to have a glow or continue combustion for a maximum of thirty seconds after the removal of the flame.
In summary, V-0 is a higher level of flame retardancy than V-1. Materials with a V-0 rating have more stringent requirements for flame extinguishment and do not show any glow or continued combustion, whereas V-1 materials can have limited glow or continued combustion for a short duration after flame removal.