UL 94:2013 pdf download – Tests for Flammability of Plastic Materials for Partsin Devices and Appliances
UL 94:2013 pdf download – Tests for Flammability of Plastic Materials for Partsin Devices and Appliances.
8.5.1 Clamp the specimen from the upper 6 mm of the specimen, with the longitudinal axis vertical, so that the lower end of the specimen is 300 ±10 mm above a horizontal layer of not more than 0.08 g of absorbent 100 percent cotton thinned to approximately 50 x 50 mm and a maximum thickness of 6 mm (See Figure 8.1).
8.5.2 Adjust the burner and confirm the nominal 50 W test flame as specified in 7.5.3 — 7.5.5.
8.5.3 The burner shall approach the speomen horizontally from the wide face at a rate of approximately
300 mrn’sec. Apply tile flame centrally to the middle point of the bottom edge of the specimen so that the top of the burner is 10 ±1 mm below that point of the lower end of the specimen, and maintain it at that distance for 10 ±05 seconds starting when the flame is fully positioned under the specimen, moving the burner as necessary in response to any changes in the length or position of the specimen. If the specimen shrinks, distorts, or melts, the point of application shall remain in contact with the major portion of the specimen
8.5.4 If the specimen drips material during the flame application, tilt the burner to an angle ol 45 ±5 perpendicular to the wide face of the specimen and withdraw it just sufficiently from beneath the specimen to prevent material from dropping into the barrel of the burner while maintaining the 10 ±1 mm spacing between the center of the top of the burner and the remaining major portion of the damaged specimen, ignoring any strings of molten material.
8.5.5 After the application of the flame to the specimen for 10 ±0.5 seconds, immediately withdraw the burner at a rate of approximately 300 mrnsec. to a distance at least 150 mm away from the specimen and simultaneously commence measurement of the aftertlame time t to the nearest second.
8.5.6 As soon as atterflaming of the specimen ceases, even if the burner has not been withdrawn to the full 150 mm distance from the specimen, immediately place the burner again under the specimen and maintain the burner at a distance 0110 ±1 mm from the remaining major portion of the specimen for an additional 10 ±0.5 seconds, while moving the burner clear of dropping material as necessary as indicated in 8.5.4. After this application of the flame to the specimen, immediately remove the burner at a rate of approximately 300 mm/sec to a distance of at least 150 mm from the specimen and simultaneously commence measurement of the afterflaine time. t2. and the afterglow time. t3 to the nearest second. Record t2 and t3. The laboratory fume hoed shall be evacuated after each specimen.
Note 1: II it is difficult to visually distinguish between flaming and glowing, a small piece of cotton, approximately 50 mm square as described in 5.13. is to be brought into contact with the area in question by holding with tweezers. Ignition of the cotton will be indicative of flaming.
Note 2: If the test flame is extinguished during either flame application the test specimen is to be disregarded and another specimen is to be tested. The only exception is in the case where the test flame is extinguished as a direct result of out-gassing from the specimen. In this case, the burner shall be reignited immediately and reapplied to the specimen so that the total time of application is 10 ±0.5 seconds.
8.6.1 The following are to be observed and recorded for each specimen:
a) Afterflame time after first flame application, t,-
b) Afterflame time after second flame application, tg-
c) Afterflame time plus afterglow time after second flame application, t + tg.
d) Whether or not specimens burn up to the holding clamp.
Note:Burned to the clamp – After allowing the sample to cool, use a soft, dry cloth to wipe away soot andeffluent residue and examine the sample 2 mm below the clamp line for signs of combustion or pyrolysis.Any thermal damage, such as melting or distortion, on the sample below the clamp, shall be neglected.
e) Whether or not specimens drip flaming particles and whether the particles ignited the cottonindicator.