UL 94 and VW-1 are two different flammability standards used to evaluate the fire resistance of materials. Here are the differences between UL 94 and VW-1:
1. UL 94: UL 94 is a flammability standard developed by Underwriters Laboratories (UL). It evaluates the performance of plastic materials used in devices and appliances. UL 94 classifies materials into different flammability ratings, ranging from V-0 (highest rating) to V-2 and V-1 (lower ratings), based on their performance in vertical flame tests.
- V-0 rating: The material self-extinguishes within 10 seconds after the removal of the ignition source, and it has no flaming drips.
- V-1 rating: The material self-extinguishes within 30 seconds after the removal of the ignition source, and it has no flaming drips.
- V-2 rating: The material self-extinguishes within 30 seconds after the removal of the ignition source, and it may have minimal flaming drips.
2. VW-1: VW-1 is a flammability test requirement specified in the UL 1581 standard for cable and wire products. It assesses the flame propagation characteristics of wire and cable jacket materials when subject to a vertical flame test. VW-1 evaluates how quickly the flame spreads along the length of the cable and whether it self-extinguishes within a specified time after the removal of the ignition source.
- VW-1 rating: This rating indicates that the cable or wire material has passed the vertical flame test and has demonstrated self-extinguishing properties. It does not specify a specific time frame for self-extinguishing.
In summary, UL 94 is a flammability standard for plastic materials used in devices and appliances, while VW-1 is a flammability requirement for cable and wire jacket materials. UL 94 evaluates materials based on their performance in vertical flame tests and assigns them specific ratings (V-0, V-1, V-2), whereas VW-1 simply indicates that the cable or wire material has passed a vertical flame test without specifying a specific rating or time frame for self-extinguishing.