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Glow Wire Flammability Test
- Jul 20, 2018 -


Conformance to IEC60695-2-11


Flammability Index GWFI

GWFI - glow-wire flammability index

The highest test temperature of a test sample of a specified thickness in three consecutive tests shall meet one of the following conditions:

a) the flame or glow of the test sample is extinguished within 30 seconds after removal of the glow wire, and the packaged crepe paper placed under the test sample does not ignite;

b) The test sample did not light up.



Light-off temperature GWIT

GWIT——glow-wire ignition temperature

The temperature above the maximum temperature of the top of the glow wire which is not ignited by the test sample of the specified thickness is 25 K (30 K higher between 900 ° C and 960 ° C) than the "three consecutive tests".


Sample requirements

The requirements of the SGS Materials Laboratory for test samples are as follows:

The sample sample should have a sufficiently large, fixed-size planar portion that is held in a vertical position during the test.


Test samples can be made in several ways:

Compression molding, injection molding or casting, or cutting from finished parts with sufficient flatness such as sheets.

The dimensions of the flat part should be:

Length: ≥60mm, width (inside of the fixture): ≥60mm

Assessing flammability according to the requirements of this test usually requires a set of 10 test samples.


Severe rating

1. Glow Wire Flammability Index (GWFI) should be selected from the following test temperatures

Test temperature / ° C: 550 / 600 / 650 / 700 / 750 / 800 / 850 / 900 / 960

2. Glow wire ignitability temperature (GWIT) should be selected from the following test temperatures

Test temperature / ° C: 500 / 550 / 600 / 650 / 700 / 750 / 800 / 850 / 900 / 960


Evaluation of results


  1. Assessment of the glow ignitability index (GWFI) results


If the test sample does not ignite or meet the following two conditions, it is considered to have withstood the test.

a) If the flame or glow line of the test sample is extinguished within 30 s after removing the glow wire

b) The packaged crepe paper does not light up

If one of the two or two conditions above is not met, select a lower test temperature and repeat the test with a new test sample.

If both of the above conditions are met, the test is repeated with a new test sample at a higher test temperature.

The test shall be repeated at the highest test temperature at which the test sample satisfies conditions a) and b).

It is to be determined that the highest test temperature for conditions a) and b) is met in three consecutive tests at GWFI.


2. Assessment of glow wire igniting temperature (GWIT) results

It shall be determined that the light-off temperature of the test sample during the application of the glow wire is recorded as GWIT at a test temperature higher than the maximum temperature of the top of the glow wire which does not cause the test sample to ignite in three consecutive tests, 25K (30K between 900 °C and 960 °C). .