What are the Tests for Flammability?
The two most common testing methods used to measure flame resistance are the Tunnel Test and the Vertical Flame Test. “Flame resistance refers to a fabric’s ability to resist burning. The appropriate flammability test is dictated by the intended end use for the fabric.”
ASTM E -84
is tested by the Tunnel Test. “In the Tunnel Test, the fabric to be evaluated is clamped (unadhered method) or glued (adhered method) to a substrate. The substrate is placed on the ceiling of the test chamber and ignited by a flame from below. The fabric sample is then evaluated for the density of the smoke formed, the amount of fuel contributed and the extent of the flame spread. Based on these factors, a rating is established.”
The Vertical Flame Test is used by both the California Technical Bulletin #117 Section E and NFPA 701 tests. “In the Vertical Flame Test, the fabric to be evaluated is mounted in a vertical holder and exposed to an open flame for a specified amount of time. Once the flame is removed, the after flame and char length of the test sample are measured against various code standards to establish a classification.
The NFPA 701
utilizes the Vertical Test but unlike California Bulletin 117, the test is conducted in ‘oven dry’ conditions, meaning the fabric to be tested is heated and thoroughly dried out prior to testing. The test then proceeds under the standards described above and a classification is established.”
SOURCE: Association of Contact Textiles Website