This Recommendation specifies a procedure for qualifying
textiles and films used primarily as vertically hanging curtains and
draperies, as meeting the requirements for the resistance to propagation
of flame specified in Regulation 3(s)(iii)footnote of Chapter 11-2 of the International
Convention for the Safety of Life at Sea, 1974. Fabrics which are
not inherently flame resistant should be exposed to cleaning or exposure
procedures and tested both before and after such treatment.
AFTERFLAME TIME. The time during which the material continues
to flame after the ignition source has been removed or extinguished.
SUSTAINED IGNITION. Afterflame time of 5 seconds or more.
AFTERGLOW. Persistence of glowing of a material after cessation
of flaming or after the ignition source has been removed.
SURFACE FLASH. The rapid flash of a flame across the surface
of the fabric primarily involving the surface pile finish and often
leaving the base fabric in an essentially undamaged condition.
The test method provides information on the ability of a
fabric to resist sustained ignition and flame propagation when exposed
to a small igniting flame. The performance of a fabric in this test
does not necessarily indicate its resistance to flame propagation
when exposed to conditions substantially different from those used
in the test.
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Health and Safety of Test Operators
Burning of textiles may produce smoke and toxic gases which can affect the
health of operators. The testing area should be cleared of smoke and fumes by suitable
means of forced ventilation after each test, then restored to the required testing
conditions.
5.1 Detailed drawings of both the test apparatus and
enclosure for this test are available from the IMCO Secretariat.
5.2
Gas burner
A gas burner should be provided as illustrated in Figure 1.footnote This should be so mounted that the axis of the burner barrel is capable
of adjustment to each of three fixed positions, viz. vertically upwards, horizontal or
at an angle of 60° to the horizontal. The positions assumed by the burner with respect
to the fabric are illustrated in Figure 2.
Figure 1 Ignition burner
Figure 2 Ignition burner - Fabric positions
5.3
Gas
Commercial grade propane of at least 95 per cent purity should
be used.
5.4
Test enclosure
A 0.5 mm - 1.0 mm thick sheet metal draught shielding enclosure
should be provided, measuring roughly 700 mm ± 25 mm x 325
mm ± 25 mm x 750 mm ± 25 mm high. The roof should be
provided with 32 circular holes, each 13 mm ± 1 mm in diameter,
symmetrically drilled, and baffled vent openings should be provided
at the base of each side giving at least 32 cm2 of free
vent area, symmetrically distributed. One 700 mm x 325 mm face should
be constructed to accommodate a closure door mainly of glass, and
one smaller side should also be constructed as a vision panel. A hole
should also be provided for the gas feed tube and remotely controlled
burner positioning rod. The floor of the enclosure should be covered
with a noncombustible insulating material. The interior should be
painted black.
5.5
Specimen holder
A rectangular test frame, 200 mm ± 1 mm long x 150 mm
± 1 mm wide should be provided, constructed of stainless steel,
10 mm wide by 2 mm thick. Mounting pins incorporating distance stubs
constructed of stainless steel 2.00 mm ± 1.00 mm diameter,
should be fixed at each corner of the test frame and at the centre
of both long members.
5.6
Base support
The test frame should be supported over a rigid metal base by
means of two vertical uprights to which the frame may be attached.
The metal base also provides a support for pivoting the burner pedestal
to move the burner flame into contact with or away from the specimen.
6.1
Preparation
The specimens should be as representative as possible of the
material provided and should exclude selvages. At least ten specimens
should be cut, each measuring 220 mm x 170 mm, five in the direction
of the warp, five in the direction of the weft. Where the fabric has
differing surfaces on the two sides enough samples should be cut for
both surfaces to be tested.
Using a template 220 mm x
170 mm, with holes approximately of 5 mm diameter located on the template
at the position of the pins on the frame, each specimen should be
laid flat on a bench and premarked/punctured, to ensure a repeatable
and reproducible tension of the specimen, after mounting on the frame.
6.2
Conditioning and exposure procedures
The specimens should be conditioned at 20°C ± 57°C
and 65 per cent ± 5 per cent relative humidity for not less
than 24 hours before test. If the material is not inherently flameproof,
one of the exposure procedures detailed in Appendix 2 may, at the
discretion of the approving authority, be applied to at least ten
further specimens.
6.3
Mounting
Each sample should be removed from the conditioning atmosphere
and either tested within three minutes or placed in a sealed container
until required. The fabric should be mounted on the pins of the test
frame in the locations previously marked on each fabric (see6.1).
The location of the fabric on the pins should be such that it is roughly
centred in the width direction and the lower edge of the fabric extends
5 mm ± 1 mm below the lower pin.
7.1
Presetting of the igniting flame
The gas burner should be ignited and preheated for at least
two minutes. The fuel supply should then be adjusted so that, when
the burner is in the vertical position, the distance between the tip
of the burner tube and the visible tip of the flame is 40 mm ±
2 mm. If desired a gas flow meter may be used as a means of achieving
reproducibility in adjusting the burner flame length.
7.2
Determining the mode of flame application
for a given fabric
The angle of the burner should be adjusted to the horizontal
position and the height fixed so that the flame, when the burner is
in position, will impinge on the fabric at a central point, 40 mm
above the level of the first row of pins. The door to the enclosure
should then be closed and the burner moved into a position such that
the burner tip is 17 mm from the face of the specimen. The flame should
be applied for five seconds and then removed. If no sustained ignition
occurs a new specimen should be fixed to the holder and the flame
applied as before but in this case for 15 seconds. Failure to achieve
sustained ignition at the longer duration requires the position of
the burner to be adjusted to a position such that the tip of the burner
lies 20 mm below the bottom edge of the fabric, the flame impinging
on it. The flame should be applied in this position to a new specimen
for five seconds and if no sustained ignition occurs another specimen
should be inserted and the time of flame application should be extended
to 15 seconds. The ignition condition to be used for testing the specimens
should be that at which sustained ignition is first achieved when
the order of test listed above is followed. In the absence of sustained
ignition the specimens should be tested under conditions showing the
greatest char length. The method of flame application for warp and
weft specimens should be determined using the ignition sequence given
above.
7.3
Flame test
Using the burner position and flame application time found to
be appropriate for the specimens under test, a further five samples
cut in both warp and weft directions should be tested as described
in 6.2 and the afterflame times noted. Any evidence of surface flash
should be noted. If afterglow is observed to occur during a test the
specimen should be allowed to remain in place until all glowing has
ceased. The extent of char is also measured. Where doubt exists as
to the precise limit of damaged fabric, the procedure detailed in Appendix 1 should be followed.
7.4
Flaming drops
To investigate if burning drops of thermoplastic materials are
capable of igniting combustible materials on the base of the apparatus,
cotton wool as specified in 3.5(2) of the Annex to resolution A.163(ES.IV)
as amended by resolution A.215(VII)footnote of
the IMCO Assembly should be laid to a depth of 10 mm over the base
plate, immediately below the specimen holder. Note should be made
of any ignition or glowing of the cotton wool.
The test report should include the following information:
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.1 name of the testing authority;
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.2 name of the manufacturer of the material;
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.3 date of supply of the material and date of
test;
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.4 name or identification mark of material;
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.5 description of material;
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.6 weight per unit area of material;
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.7 conditioning of samples and exposure procedures
used, if any;
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.8 mode of flame application used;
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.9 duration of flame application;
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.10 afterflame, length of char and ignition of
cotton waste from drops, as applicable;
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.11 type of cleaning and weathering procedures
used, if any.