Table Of Content
Table Of Content
CSA fire rating:
FT1: vertical burning test (no requirement for dripping)
FT2: Horizontal Flame Test
FT3: vertical burning combustible drop test (newsprint cannot be ignited)
FT4: Do a vertical combustion test in a closed combustion chamber (similar to a closed building) with a thermal energy of 70,000 btu/h
FT5: Flame resistance test, usually used in portable CABLE for underground operations
UL fire rating:
A: Horizontal fire test
B: VW-1: vertical fire test, drippings cannot ignite cotton wool.
VW-1SC: vertical fire test, insulated core wire and finished wire are tested separately.
C: CL2 (VERTICAL TRAY FLAM TEST):
Do a vertical combustion test in a closed combustion chamber (similar to UL1581 in a closed building)
D: CL2R (RISET CABLE)
E: CL2P (PLENUM CABLE)
F: CM (COMMUNICATION CABLE communication line); G: CMR; H: CMP.
The content of UL plastic material 94-V0 (94V0 is the so-called flame-retardant grade, which is divided into 5 grades) 94-V0 will extinguish as soon as the fire leaves when it burns, and it will not ignite spontaneously.
When 94-V1 is burning, it will burn for 1 second and then go out immediately after the fire leaves, it will not spontaneously ignite
When 94-V2 is burning, it will burn for 2 seconds and then go out immediately after the fire leaves, it will not ignite spontaneously
When 94-V5 is burning, it will burn for 5 seconds and then go out immediately after the fire leaves, it will not ignite spontaneously
When 94-HB burns, once the fire leaves, it will burn until only carbon remains
Comparison of UL94 Plastic Flammability Rating and UL 1581 VW-1 Flammability Rating
There are 12 types in UL94: HB, V-0, V-1, V-2, 5VA, 5VB, VTM-0, VTM-1, VTM-2, HBF, HF-1, HF-2.
Flammability UL94 ratings are the most widely used standards for the flammability of plastic materials. It is used to evaluate the ability of a material to extinguish after being ignited. According to the burning speed, burning
There are many ways to judge time, anti-dripping ability and whether the dripping beads burn. Each measured material can have many values depending on color or thickness. When selecting a product
When the material is used, its UL rating should meet the thickness requirements of the wall part of the plastic part. The UL rating should be reported together with the thickness value, it is not acceptable to report only the UL rating without the thickness
enough.
The flame retardant grade of plastic is gradually increased from HB, V-2, V-1, V-0, 5VB to 5VA:
HB: The lowest flame retardant grade in the UL94 standard. It is required that for samples 3 to 13 mm thick, the burning rate is less than 40 mm per minute; for samples less than 3 mm thick,
The burning speed is less than 70 mm per minute; or it goes out before the 100 mm mark.
V-2: After two 10-second combustion tests on the sample, the afterflame & afterflame were extinguished within 60 seconds. Dripping particles can ignite cotton.
V-1: After two 10-second combustion tests on the sample, afterflame & afterflame extinguished within 60 seconds. Dripping particles must not ignite cotton.
V-0: After two 10-second combustion tests on the sample, afterflame & afterflame extinguished within 30 seconds. Dripping particles must not ignite cotton.
5VB: After five 5-second combustion tests on the sample, afterflame & afterflame extinguished within 60 seconds. Dripping particles must not ignite cotton. Burn-through is allowed for bulk samples.
5VA: After five 5-second combustion tests on the sample, afterflame & afterflame extinguished within 30 seconds. Dripping particles must not ignite cotton. For block samples do not allow to be burned
Put on.
The wire burning method in UL1581:
1. VW-1: vertical burning test (UL wire burning level)
2. FT1: vertical burning test;
3. FT2: horizontal combustion test;
4. FT4: vertical burning test;
5. FT6: Horizontal combustion and smoke test. (The flammability level of the FT class is the wire combustion level of the CSA standard)
Among the above grades: .VW-1 is the same grade as FT1. FT2 is the easiest to pass and has the lowest level. (FT6>FT4>FT1>FT2);
VW-1 is stricter than FT1, both of which are vertical burning, judging criteria: 1. The burning mark (kraft paper) cannot be carbonized by more than 25%; 2. Five times of 15 seconds of continuous burning
The burning time cannot exceed 60 seconds; 3. The burning drop cannot ignite the cotton; VW-1 requires to meet 1, 2, 3; FT1 only requires to meet 1, 2
For the wire industry:
The V-2, V-1, V-0, 5VA, 5VB of UL 94 assess the materials used in the wires, and the test materials should be used to formulate standard samples during the test, which will not be marked on the wires. the
VW-1 VW -2 FT-1 FT-2 assesses the wire itself. After passing the test, the corresponding grade can be marked on the wire.
The flame retardancy of wires is completely different from the flame retardancy of UL94. For example, an insulating material can pass V-0 of UL94 but not necessarily VW-1;
In addition, UL94 is flame retardant for insulating materials, and the flame retardant requirements for wires are generally on UL758 62 1581; the objects are different;
Therefore, the flame retardancy in UL94 such as V-0 V-1 is not the flame retardancy of wires at all; there is no “V-0” printed on AWM wire!
The V0 combustion test in VW-1/FT1 and UL94 is very different in equipment:
1. The height and temperature of the flame are different
2. The methane flow rate used in the test is also different
3. The back pressure of methane is also different
4. The volume of the combustion box is also different: VW-1 requires more than 4 cubic meters, while V0 only requires more than 0.5 cubic meters.
5. The burning times are also different
6. In the combustion result: V0 requires recording the residual burn time, but VW-1 does not!
However, the test conditions and test methods for 5V combustion and VW-1 combustion in UL94 are similar, and relatively close!
the
Remind everyone: Whether it is VW-1 or UL94 combustion test equipment, it must refer to ASTM5025 and ASTM5027,
UL1581 and UL94 are only test methods, and the requirements for test equipment must be in accordance with ASTM standards!
Differences between UL94 and VW-1 tests on equipment
In the UL94 combustion test, there are combustion tests such as HB, V0, V1, V2, VMT, 5VA, and 5VB, while in UL1581 there are combustion tests such as VW-1, FT1, FT2, and FT4.
The differences between the two tests in terms of equipment are as follows:
VW-1\FT1 blowtorch: 125mm (500W), combustion flame: inner flame height 40±2mm, outer flame 125±10mm
UL94 HB, V class blowtorch: 20mm (50W), combustion flame: no cone in the blue flame, height 20±1mm
The 5V class combustion in UL94 uses 125mm (500W), combustion flame: inner flame height 40±2mm, outer flame 125±10mm
The flame temperature of the flame is also different:
20mm (50W) test flame: 100±2~700±3℃ for 44±2S.
125mm (500W) test flame: 54±2S at 100±2~700±3°C.
The test space is also different:
HB, V, and VMT in UL94 only require a space greater than 0.5 cubic meters, while 5V requires more than 0.75 cubic meters
VW-1 requires more than 4 cubic meters
Differences between UL94 and VW-1 tests on equipment
In the UL94 combustion test, there are combustion tests such as HB, V0, V1, V2, VMT, 5VA, and 5VB, while in UL1581 there are combustion tests such as VW-1, FT1, FT2, and FT4.
The differences between the two tests in terms of equipment are as follows:
VW-1\FT1 blowtorch: 125mm (500W), combustion flame: inner flame height 40±2mm, outer flame 125±10mm
UL94 HB, V class blowtorch: 20mm (50W), combustion flame: no cone in the blue flame, height 20±1mm
The 5V class combustion in UL94 uses 125mm (500W), combustion flame: inner flame height 40±2mm, outer flame 125±10mm
The flame temperature of the flame is also different:
20mm (50W) test flame: 100±2~700±3℃ for 44±2S.
125mm (500W) test flame: 54±2S at 100±2~700±3°C.
The test space is also different:
HB, V, and VMT in UL94 only require a space greater than 0.5 cubic meters, while 5V requires more than 0.75 cubic meters
VW-1 requires more than 4 cubic meters
The flow requirements of methane are different:
The gas flow rate of HB, V and VMT grades is 105ml/min, and the back pressure is 10mm water column or equivalent pressure;
5V level gas flow rate is 965ml/min, 125±25mm water column or equivalent pressure
VW-1 is the same as the 5V level back pressure in UL94: the gas flow rate is 965ml/min, 125±25mm water column or equivalent pressure
(Note: At present, many plastic UL94 burners in China are not equipped with a dedicated methane flow meter (often replaced by an air flow meter, which causes a big difference!),
In addition, there is no U-shaped back pressure gauge! , more importantly: not equipped with a flame temperature measurement system), you can check your equipment!
