3 Performance requirements
3.1 Photometric requirements
The minimum coefficient of retro-reflection (R') when illuminated by CIE
Standard Illuminant A (colour temperature 2856 K) should be as specified in table
3.1 for the retro-reflective areas of new and dry material when tested as described
in section 4.2. The brightness of the retro-reflectivematerial, when tested as
described in section 4.9, should be not less than 80% of the table 3.1 values.
Table 3.1
Minimum coefficient of retro-reflection R' in cd·lx
-1· m-2
| Entrance angle B1
(B2=0)
|
Observation
angles
|
| 0.1°
|
0.2°
|
0.5°
|
1°
|
| 5
|
180
|
175
|
72
|
14
|
| 30
|
140
|
135
|
70
|
12
|
| 45
|
85
|
85
|
48
|
9.4
|
3.2 Accelerated weathering
Applied to an aluminium test panel, the material should show no significant
discoloration, cracking, blistering or dimensional change, and should have not less
than 80% of the specified minimum reflective intensity values in table 3.1, when
tested as described in section 4.10.
3.3 Seawater immersion
Where tested as described in section 4.3, the material should show no evidence of
blistering, delamination or subsurface corrosion. The material should show no
evidence of "whitening" and its retro-reflective intensity should not be reduced
below the retro-reflective values in table 3.1, except within 5 mm of each side of
the required cuts.
3.4 Flexibility
There should be no cracking of the retro-reflective material, after conditioning for
4 hours at -30° C, when bent around a 3.2 mm mandrel and tested as described in
section 4.4.
3.5 Tensile strength
Tensile strength N (newton) per 25 mm width:
-
| material without support
|
≥16 N
|
| material with support
|
≥330 N
longitudinal
|
| for mechanical fastening
|
≥200 N
transverse,
|
when tested as described in section 4.5.
3.6 Adhesive strength
For adhesive-backed material only. The adhesive strength should be not less than 16 N
per 25 mm width when tested as described in section 4.6.
3.7 Blocking
The material should show no blocking when tested as described in section 4.7.
3.8 Salt spray resistance
The material should show no evidence of corrosion or degradation that would impair
its effectiveness or reduce the coefficient of retro-reflection below the values in
table 3.1 after exposure to a saline mist for 120 hours followed by cleaning with a
dilute neutral detergent solution as described in section 4.8.
3.9 Temperature resistance
The material should show no evidence of cracking, distortion, or loss of coefficient
of retro-reflection below the values in table 3.1 after exposure, in a dry
atmosphere, for 24 hours to a temperature of 65 ± 2°C and subsequent exposure for 24
hours to a temperature of -30 ± 2°C.
3.10 Fungus resistance
Applied to an aluminium test panel, the material should not support fungus growth,
should show no loss of coefficient of retro-reflection below the levels in table
3.1, and should not be removable from the test panel without damage, when tested as
described in section 4.11.
3.11 Abrasion resistance
Applied to an aluminium test panel, the material should not have less than 50% of the
specified minimum reflective intensity values in table 3.1, when tested as described
in section 4.12.
3.12 Soil resistance and cleanability
Applied to an aluminium test panel, the material should not have any significant
visible damage or permanent soiling when tested as described in section 4.13.
4 Test methods and interpretation of test results
4.1 Test conditions and number of samples
Test specimens should be conditioned for 24 hours at a temperature of 23 ± 1°C and 50
± 5% relative humidity before being tested. All test results should be interpreted
as the average obtained from testing at least three specimens.
4.2 Photometric performance
The photometric performance should be measured using the general procedure
recommended by CIE Report No.54, 1982. The sample dimensions should be 150 mm by 150
mm. Entrance and observation angles should be as specified in table 3.1. Readings
should be taken at not greater than 30° increments as the observation half-plane is
rotated about the reference axis (i.e. at rotation angles (ε) of 0°, 30°, 60°,
90°,120°, 150° and 180°). Each measured value should be the average of the readings
for all of the required samples.
4.3 Seawater immersion
4.3.1 Prepare a 75 mm x 150 mm test panel.
-
(A) material without support: After removing protective liner paper, apply
specimens to a clean aluminium panel surface, using a hand-roller for
application.
-
(B) material with support for mechanical fastening: Tape edges of test
specimens to a clean aluminium panel.
4.3.2 The retro-reflective material on each test panel is cut with a sharp knife from
each corner diagonally opposite so that an "X" is formed. The cuts must be made
completely through the material to the metal panel.
4.3.3 Immerse the test panels to half-length in a 4% (by weight) saltwater solution
(4 g NaCl dissolved in 96 ml distilled water) at 25°C, using a glass beaker covered
by a glass plate. After a 16-hour immersion period, remove the panels from the
beaker, rinse salt deposits from the panels, and examine the sample following a
10-minute recovery period and again after 4 hours for compliance with the
requirements described in section 3.3.
4.4 Flexibility
4.4.1 Condition test specimen for 4 hours in a cold chamber at -30°C. A
3.2 mm mandrel should be conditioned at the same temperature. The sample should be
bent over the free-standing mandrel, gently applying gloved finger pressure.
4.4.2 For material without support, remove protective liner and talc the adhesive to
prevent sticking.
4.5 Tensile strength
Prepare three test samples 25 mm in width and 150 mm in length. Insert samples into
the grips or jaws of the testing machine so that the load is distributed evenly
across the width of the samples and the initial test length is 100 mm. Determine
tensile strength at a speed of 300 mm per minute. Record average tensile strength at
break in newtons per 25 mm width for all three test samples. For material without
support, remove protective liner paper before inserting samples in the tensile
tester.
4.6 Adhesive strength (for material without support only)
4.6.1 Prepare three test samples 25 mm in width and 200 mm in length for each type of
surface to which the material is to be applied. Remove protective liner paper for 80
mm in length and apply test specimens to the test surfaces. Test surfaces should be
aluminium, GRP, each type of lifejacket and lifebuoy that the material is to be used
on, and inflatable liferaft buoyancy tube material. Test surfaces should be 50 mm in
width, 90 mm in length, and of the thickness normally used and should be properly
cleaned by wiping the surface with a suitable solvent.
4.6.2 Apply test specimens with a solid brass roller, 80 mm in diameter and 40 mm in
width covered with rubber approximately 6 mm thick and having a hardness of 80 ± 1
RHD and a total mass of approximately 2 kg. Use three passes for roller application
and allow to have a 120 mm free overlap strip to be used for inserting into the jaw
clamp of the testing instrument. One test panel should be immersed in distilled
water in a covered container for 16 hours before adhesive strength testing and the
other test panel should be immersed in salt water (4% NaCl by weight) in a covered
container for 16 hours before adhesive strength testing (this test method is
required only for retro-reflective material that is designed for use with an
adhesive. If a particular test panel used in testing results in a test failure, the
retro-reflective material should not be approved for attachment to material of the
type used in the test panel). Peel back at an angle of 180° at a speed of 300 mm per
minute. Record adhesive strength in newtons per 25 mm width. Repeat the adhesive
strength tests on samples subjected to the weathering test in section 4.10.
4.7 Blocking
Stack two 100 mm x 100 mm pieces of material, retro-reflective face to
retro-reflective face, between two pieces of glass plate 3 mm thick of the same size
as the samples and place in an air-circulating oven operating at 65°C. Place an 18
kg weight centrally on the top glass plate and close the oven. After 8 hours, remove
the test assembly from the oven, take the retro-reflective material from between the
plates and cool for 5 min. Separate the two pieces of retro-reflective material and
examine for evidence of adhering or peeling of the surface.
4.8 Salt spray resistance
4.8.1 Prepare test specimens as described in section 4.3 (A) and (B), respectively,
and expose them to a salt spray chamber.
4.8.2 The test should consist of five periods of 22 hours' exposure each, separated
by an interval of 2 hours during which samples are allowed to dry. The saline mist
should be produced by atomizing, at a temperature of 35 ± 2°C, a saline solution
obtained by dissolving five parts of NaCl in 95 parts of water, containing not more
than 0.2% of impurities.
4.9 Photometric performance when wet
An unweathered 150 mm x 75 mm specimen should be mounted in a vertical plane, with
the 150 mm dimension oriented horizontally. Apply sufficient water so that the
entire specimen surface is covered by a continuous moving film of water. Measure the
coefficient of retro-reflection at 0.2° observation angle and 5° entrance angle. An
example of an appropriate test apparatus is shown in figure 1.
Figure 1
4.10 Accelerated weathering
4.10.1 The photometric performance of the material should be determined according to
section 4.2 after the material has been exposed in a sunshine carbon arc
weatherometer for the following periods:
-
| Type I material:
|
750 h
|
| Type II material:
|
1,500 h
|
4.10.2 Alternative light sources other than a carbon arc may be used and exposure
times for such sources should give an equivalent degree of accelerated weathering.
Accelerated weathering should follow the test methodology in accordance with an
international standard acceptable to the Organization.footnote
4.10.3 After exposure, the material should be examined for the requirements and
characteristics in section 3.2.
4.11 Fungus resistance
4.11.1 Prepare three 75 mm x 75 mm test panels as described in section 4.3 (A).
Prepare three additional test panels as described in section 4.3 (B), using
non-rusting, non-staining clips or fasteners (in lieu of tape) to hold the material
flat. Expose the panels to mildew, using the soil burial method, for a period of 2
weeks. The microbial activity of the soil should be verified by exposing untreated
cotton fabric of 400 g/m2 to 475 g/m2 to the soil bed for the
first 5 days. The soil should be considered to be satisfactory if this control
sample loses not less than 50% of its original tensile strength during this
exposure.
4.11.2 At the end of the exposure period, the test panels should be removed from the
soil bed, gently washed to remove soil, and wiped with a soft cloth wet with a 70%
ethanol solution. Condition the panels under standard conditions for 48 hours. Test
the photometric performance of the specimens as described in section 4.2 and, when
finished, attempt to remove the material from the test panel.
4.12 Abrasion resistance
4.12.1 An apparatus is required which should consist of an electric motor mounted on
a flat metal plate, and a mechanism through which the motor will impart a
reciprocating motion to a brush lengthwise across the full length of a test panel
clamped to the plate. Prepare one test panel 150 mm wide x 425 mm long, as described
in section 4.3 (A). Mount the panel firmly on the test apparatus and place the brush
on the panel.
4.12.2 The block of the brush should be aluminium, 90 mm long x 40 mm wide and 12.5
mm thick. The brush stock should be stiff, black, butt-cut Chinese hog bristle.
There should be 60 holes on the block, 4 mm in diameter, solidly filled with
bristle. The bristles should extend 20 mm beyond the block to form an abrading
surface as nearly planar as possible. The total weight of the brush should be 450 ±
15 g. Weights may be fastened to the top of the brush to attain this weight.
4.12.3 Start the motor. The apparatus should be adjusted so that the brush travels at
a rate of 37 ± 2 cycles (74 ± 4 strokes) per minute. Remove the panel after 1,000
brush strokes and wipe with a clean, soft cloth. Test the photometric performance of
the material, as described in section 4.2.
4.13 Soil resistance and cleanability
Prepare a test panel 150 mm x 150 mm, as described in section 4.3 (A). Soil the panel
by applying a film, 90 mm wide x 0.075 mm thick, of thoroughly mixed soiling medium
across the middle of the test panel. The soiling medium should consist of a mixture
of 8 g carbon black, 60 g mineral oil and 32 g odourless mineral spirits. Cover the
soiled area for 24 hours with a laboratory watch glass or similar device. Uncover
the material and wipe off the soiling medium with a clean, dry, soft cloth. Wet the
material with mineral spirits and wipe with a cloth soaked in mineral spirits. Wash
with a 1% (by weight) solution of detergent in warm water, rinse, and dry with a
clean, dry, soft cloth. Examine the sample for compliance with section 3.12.