Determination of fire code rating (BKZ)

on Textiles according to the Directive for Fire Police Prescriptions (VKF)
The determination of fire code rating is based on two tests. One test is for the flammability and the other for the smoke density. For flammability, two tests are possible depending on the nature of the material. The flammability test in accordance with SN 198898 is for textiles only, and the flammability test in accordance with VKF for solid construction materials. Textiles, particularly those which are not made with low combustibility fibers, can be influenced by cleaning treatment and therefore such textiles should be tested in their original state and after the cleaning treatment. The flammability grade 5 can only be reached when the material passes the tests in its original state and after the cleaning treatment.
https://sasp20.empa.ch/documents/56038/91259/VKF.jpg/a81a5000-cf91-4651-a4ad-eb53bb12af2b?t=1480413120000
Determination of flammability in accordance with SN 198’898 (1987)

Test procedure

The conditioned samples are hung vertically in the burning chamber. The lower edges of the samples are put into contact with a propane gas flame (40 ± 2 mm in length) for 3 s and 15 s. The burner is inclined by 30° relative to the vertical axis. The damage length and the afterglow time are assessed for samples which do not ignite. For samples that do ignite the after flame time is recorded and where applicable the rate of flame spread between two points is determined.

Requirements according VKF

Flammability grade 5 is reached when at least 18 of the 20 samples meet all of the below requirements. If grade 5 is not reached the sample is deemed to have failed the test.

Determination of flammability (test acc. VKF)

Test procedure

The conditioned samples are hung in the burning chamber. The lower edges of the samples are put into contact with a propane gas flame (20mm in length) for 15 s. The burner is inclined by 45° relative to the vertical axis.

The samples are classified based on a) the time it takes for the flame to burn 150 mm from the bottom of the sample, and b) the duration of time that afterglow is observd.

Determination of the Smoke Density in accordance with VKF

Test procedure

Smoke density is determined by exposing the test sample (30 x 30 x 4 mm and/or least 2 g) to a defined flame in the standardized apparatus with a controlled air flow until the sample has been completely burnt. In the course of this test, the maximum measurable light absorption of the generated smoke is determined by photometry.

Requirements

The smoke density is determined for three tests. Should the results not agree, up to six tests will be conducted and the maximum and minimum values excluded; the average of the results is used for the classification.

 

If you have any queries regarding the suitability, cost or time frames associated with this testing, please do not hesitate to contact us.

Relevant standards

Determination of flammability in accordance with SN 198’898 (1987)
(Withdrawn 1999-07-01)

Here you will find all information about the Test specifications from VKF.