Definition of Flame Retardancy: A grade that is distinguished by the nature of the material that has or has been treated to significantly retard the flame spread.
Grade: 1, HB: UL94 standard in the end of the flame retardant grade. For samples of 3 to 13 mm thick, the burning rate is less than 40 mm per minute; for samples less than 3 mm thick, the burning rate is less than 70 mm per minute; or extinguished before the 100 mm mark.
2, V-2: the sample for 10 seconds after two burning tests, the flame in 60 seconds off. There may be a fall in the combustion.
3, V-1: After two 10-second burning tests, the flame is extinguished in 60 seconds. Can not have the combustion material to fall off.
4, V-0: After 10 seconds of burning test, the flame is extinguished in 30 seconds. Can not have the combustion material to fall off
Test procedure: UL94HB
Samples: 5 'x 1/2' x thickness (typical thickness is 1/16 ', 1/8', 1/4 ')
Procedure:
Three samples per thickness were tested and the samples were conditioned at 20 ° C and 50% RH for 48 hours prior to testing. Samples should be placed in parallel with the long axis, with the short axis into 45? Angle. For each sample, draw two lines 1 'and 4' from one end.
A blue flame with a height of 1 'was placed on the end of the sample and left for 30 seconds and then removed. If the sample continues burning after the flame is removed, the time to burn the sample between the two width marks is measured, and the burning ratio is calculated in inches per minute.
Level requirements: 94HB
A: For specimens having a thickness between 0.120 'and 0.500', a span not exceeding 1.5 'per minute, greater than 3.0', or
B: For samples with a thickness of 0.120 ', no more than 3.0' span can be exceeded, or
C: The sample ignited spontaneously when the flame did not touch the 4.0 'mark.
UL94V-0, V-1, V-2
Samples: 5 'x 1/2' x thickness (typical thickness 1/16 ', 1/8', 1/4 ')
A total of 10 samples (2 sets) are tested for each thickness. Five samples of each thickness were allowed to stand for 48 hours at 23 ° C, 50% RH and then tested. Five samples of each thickness were tested at 70 ° C for 7 days.
The sample is placed perpendicular to the long axis and mounted. Install the lower end of the sample from the top of the combustion tube 3/8 '. Place a 3/4 blue flame at the lower center of the sample and burn for 10 seconds.
If the sample drips down, the liquid drops onto a layer of unprocessed cotton underneath the sample. This layer of cotton is placed 12 'below the sample.
Level requirements:
94V-0
A: No samples were burned for more than 10 seconds after the test flames were removed.
B: For each set of 5 samples, the total time of burning with flames after 10 flashes exceeded 50 seconds
C: No sample has been burned on the fixture (including flames burning and red burning)
D: Without any sample, the combustion melts the droplets and drips the cotton at 12 'below.
E: None of the samples, after a second removal of the test flame, continued to flare for more than 30 seconds.
94V-1
A: No sample was burned for more than 30 seconds after the test flame was removed.
B: For each set of 5 samples, the total time for burning with flames after 10 flashes exceeded 250 seconds
C: No sample has been burned on the fixture (including flames burning and red burning)
D: Without any sample, the combustion melts the droplets and drips the cotton at 12 'below.
E: None of the samples, after the second removal of the test flame, continued to burn red for more than 60 seconds.
94V-2
A: No sample was burned for more than 30 seconds after the test flame was removed.
B: For each set of 5 samples, the total duration of the combustion with the flames after 10 ignitions exceeded 250 seconds.
C: No sample has been burned on the fixture (including flames burning and red burning)
D: Allow the sample to burn The melted drops drip to ignite the cotton below 12 ', but the cotton burns for a short time.
E: None of the samples, after the second removal of the test flame, continued to burn red for more than 60 seconds.
UL94-5VA or UL94-5B
According to the results of the sample test, the material should be divided into 94-5VA or 94-5VB
The test procedure is as follows:
The sample without burn-through was 94-5 VA
The burn-in sample was 94-5VB
Samples: 5 'x 1/2' x thickness (bar) 6 'x 8' x thickness (plate) typical thickness (1/16 ', 1/8', 1/4 ')
Procedure for Rod-like Samples (Method A):
2 sets A total of 10 samples to be tested.
Five samples per thickness were tested after 48 hours at 23 ° C and 50% RH.
Five samples per thickness were tested after 7 days at 70 ° C.
For rod-like samples, install perpendicular to the long axis.
A 5 'flame was placed and a 1/2' inner flame was placed at the corner of the lower end of the sample at an angle of 20 to the vertical. So that the tip of the inner flame is brought into contact with the sample.
Flame burning 5 seconds, moving 5 seconds, this action is repeated until the sample after 5 burning.
Level requirements:
A: None of the samples burned for more than 60 seconds after the fifth ignition, including flaming and reddening.
B: No sample burns the melted droplets to ignite the underlying cotton.
Procedure for plate-like sample (Method 2)
Same as bar-shaped sample: 3 samples (2 sets) horizontally mounted, the flame on the center of the bottom burn.