Test Principle

A sample is held horizontally in a U-shaped holder and is exposed to the action of a defined low-energy flame for 15s in a combustion chamber, the flame acting on the free end of the sample. The test determines if and when the flame extinguishes of the time in which the flame passes a measured distance.

Sample Preparation

Take 5 samples from the tested items. If the object burns at a different speed in different directions, the sample should be intercepted and tested separately in different directions. The method of sample interception is as follows.

1 When the article is intercepted by width, the sample should be intercepted containing the full width and at least 500mm length, and the material from the edge of the 100mm shall be cut off, then intercept the samples equidistant and evenly in the rest article.

2 If the shape and size of the article meet the sample requirement, intercept the sample normally from the article.

3 If the shape and size of the article do not meet the requirements, and the test must be carried out according to this standard. The test samples (356mm*100mm) should be made by the same material and process like the same structure of the article, and the thickness of which should not exceed 13mm. This test result cannot be used for identification, certification, etc., and it must be indicated in the test report.

4 If the thickness of the article is more than 13mm, the thickness of the sample including the exposed surface is 13mm by mechanical cutting from the non-exposed surface.

5 If the thickness of the article is not uniform, make the thickness of the article uniform to the minimum thickness by mechanical cutting from the non-exposed surface.

6 If the bend of the article fails to intercept the flat specimen, the flat part of the article should be taken as far as possible, and the arch height of the specimen shall not exceed 13mm; If the arch height more than 13mm, the test samples (356mm*100mm) should be made by the same material and process like the same structure of the article, and the thickness of which should not exceed 13mm.

Test Step

1 The sample should be adjusted, at least 24 hours, but not more than 168 hours, under the standard environment of 23±2 ℃ and 45%~55% relative humidity before the experiment.

2 Place the sample in the sample holder so that the exposed side will downwards to the flame.

3 Adjust the gas flame to a height of 38 mm using the mark in the chamber, the air intake of the burner being closed. Before starting the first test, the flame shall burn at least 1 min for stabilization.

4 Push the sample holder into the combustion chamber so that the end of the sample is exposed to the flame, and after 15s cut off the gas flow.

5 The measurement of the burning time starts at the moment when the foot of the flame passes the first measuring point. Observe the flame propagation on the side burning faster than the other (upper or lower side).

6 Measurement of burning time is completed when the flame has come to the last measuring point or when the flame extinguishes before coming to the last measuring point. If the flame does not reach the last measuring point, measure the burnt distance up the point where the flame extinguished.

7 Insofar as the sample does not ignite or does not continue burning after the burner has been extinguished, or when the flame extinguishes before reaching the first measuring point so that no burning time is measured.

Test Result

1 Expose the sample to a flame for 15s, if the specimen does not burn after extinguishing the source of the fire, or the sample can burn, but the flame is extinguished before reaching the first measuring line, there has no combustion distance can be counted, so the combustion rate requirement is considered to be satisfied, and the result is recorded as A-0mm/min.

2 If the flame is extinguished within 60 seconds since starting the test timing and the combustion distance is not more than 50mm, it is also considered to satisfy the requirement of combustion rate, and the result is recorded as B.

3 If the flame is extinguished between two measuring standard lines since starting the test timing and does not meet the requirements of 2 above, the combustion rate should be calculated, and the result is recorded as C- combustion rate.

4 The flame burns to the second standard line since starting the test timing, record the actual burning time if the burning time less than 20min, and record the burning time as 20min if the burning time exceeds 20min, then calculate the burning rate. The result is recorded as D-combustion rate.

5 If the sample has been burned to the first standard line within 15s of flame ignition, it is considered that the sample cannot meet the requirements of combustion rate, and the result is recorded as E.