Flammability UL 94 VTM

Vertical Thin Material

This method is used to determine the UL 94 VTM-0, VTM-1 and VTM-2 flammability ratings of thin materials. Failure to pass the UL 94 V test is a precondition of all VTM ratings.

The test evaluates both the burning and afterglow times and dripping of the burning test specimen.

Pre-treatment:
2 days / 23 °C / 50 % relative humidity
7 days / 70 °C / hot air oven

Flame height 20 mm
Flame application time 2 x 3 s
The second flame application time begins as soon as the first burning time ends

 

Flammability rating UL 94 VTM
Test criteria VTM-0 VTM-1 VTM-2
Burning time of each individual test specimen (s)
(after first and second flame applications)
≤ 10 ≤ 30 ≤ 30
Total burning time (s)
(10 flame applications)
≤ 50 ≤ 250 ≤ 250
Burning and afterglow times after second flame application (s) ≤ 30 ≤ 60 ≤ 60
Dripping of burning specimens (ignition of cotton batting) no no yes
Combustion up to holding clamp (specimens completely burned) no no no