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Flammability |
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Introduction |
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Thermoplastics, like all organic substances, are flammable and therefore, all risks come with it must be taken into account. The materials performance against fire is determined by
characteristic parameters, such as flammability, contribution to flame spread and heat evolution,
and secondary phenomena of the fire, i.e. smoke density and composition of the combustion gases.
These parameters are greatly influenced by factors relating to the material and its environment,
such as spatial distribution, condition of the material, thermal history, thermal conductivity, type and
intensity of the ignition source, duration of exposure to the ignition source, type of structure, and
ventilation. Therefore, the material¡¯s performance against fire does not purely dependant upon
its property.. |
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Standards |
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UL 94 : US UL(Underwriters Laboratory) |
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Flammability : 5VA > 5VB > V-0 > V-1 > V-2 > HB |
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IEC 707 |
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CSA 22.2, No.0.6 (Test A~J) : Canadian flammability requirements on electric and
electronic product housings |
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Standard Tests |
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Measurement of Burning Speed (UL 94, HB Test) |
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Measurement of Burning Time (UL 94, Vertical Test) |
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Measurement of an Oxygen Index |
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Test method (UL 94 standard) |
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UL 94HB : Horizontal Burning Test |
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Specimen : 5 X 1/2 ¡É X thickness (5 specimens) |
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Aging conditions of the specimen : 23 ¡É , RH 50%, more than 48 hours. |
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Flame is applied to the specimen for 30 seconds |
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Certification Requirements |
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| Specimen Thickness
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UL 94HB Requirement
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| 3.0 ~ 3.2 mm
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Burning Rate < 40 mm/min
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| Up to 3.0 mm
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Burning Rate < 75 mm/min
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UL 94V
: Vertical Burning Test |
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Specimen : 5 X 1/2 " X
thickness (5 specimens) |
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Aging conditions of the specimen : Identical with HB Test |
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The flame is applied to the center lower edge of the specimen for 10 seconds, as
shown below. |
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If burning ceases within 30 seconds, flame is re-applied for an additional
10 seconds, then the burning and
glowing time are measured. |
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Flame : Methane gas, blue, single flame, 3/4
"high |
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Certification
Requirement |
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94 V - 0
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94 V -
1
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94 V -
2
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| Burning
time after each application
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¡Â 10 sec
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¡Â 30 sec
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¡Â 30 sec
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| Total
burning time per set of
specimens (5 specimens)
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¡Â 50 sec
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¡Â 250 sec
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¡Â 250 sec
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| Glowing
time, seconds(individual)
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¡Â 30 sec
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¡Â 60 sec
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¡Â 60 sec
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| Ignition
of the cotton layer by
dripping
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No
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No
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Yes
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UL 94 5V Test (Bar Test, Plaque Test) |
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Bar
Test |
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- Specimen : 5 ¡± X 1/2 ¡° X
thickness |
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- Aging conditions of the specimen
: identical with the HB Test |
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- Apply flame 1 to 5 times for 5
seconds at a time |
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- Apply flame to the lower end of
the specimen at an angle of 20¡£ |
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- Flame : double flame( inner flame
: 1.5 inch / outer flame : 5 inch ) |
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Plaque Test |
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- Specimen : 6 " X 6 " X
thickness |
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- Aging conditions of the specimen :
identical with the HB Test |
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- Apply flame 1 to 5 times for 5
seconds at a time |
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- Apply flame to the panel from
below at an angle of 20o |
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- Flame : double flame( inner flame
: 1.5 inch / outer flame : 5 inch ) |
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Certificate Requirements |
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94 5VA
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94 5VB
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| Burning and glowing time after the fifth
application of the flame
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¡Â 60 seconds
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¡Â 60 seconds
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| Holding of plaque after application of
the flame
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No
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Yes
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Oxygen index : Minimum oxygen density required to by the
combustion of plastics. |
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Resin
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O.I. (%)
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Resin
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O.I. (%)
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¥â -Fiberglass
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100
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P S
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18.1
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Teflon
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95
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P E
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17.4
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P V C
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47
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P P
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17.4
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Nylon
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24~29
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PMMA
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17.4
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PC
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26~28
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Paraffin
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16.0
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