Introduction to the fire rating of the hottest pla

Plastic fire protection, including structural body parts and external sprayable parts level introduction

flammability UL94 grade is the most widely used flammability standard for plastic materials. It is used to evaluate the ability of materials to extinguish after being ignited. There are many evaluation methods according to the burning speed, burning time, anti dripping ability and whether the droplet burns. Many values can be obtained for each tested material according to its color or thickness. When the material of a product is selected, its UL grade shall meet the thickness requirements of the plastic part wall. UL grade should be reported together with thickness value. It is not enough to report only UL grade without thickness. Fire rating classification of various types of plastic products V colloidal particles: 94hb, 94v-2, 94v-1, 94V-0, VB, VAV foam: 94hbf, HF-1, hf-2v film: 94vtm-0, vtm-1, vtm-2 I. The flame retardant grade of colloidal particles plastic increases from Hb, V-2, V-1, v-0,5vb to 5VA step by step: the lowest flame retardant grade in hb:ul94 standard. It is required that the combustion rate of 3 to 13 mm thick samples is less than 40 mm per minute; For samples less than 3 mm thick, the burning rate is less than 70 mm per minute, or extinguished in front of the 100 mm mark. V-2: after two 10 second combustion tests on the sample, the residual flame and residual combustion will be extinguished within 60 seconds. Dripping particles can ignite cotton. V-1: after two 10 second combustion tests on the sample, the residual flame and residual combustion will be extinguished within 60 seconds. Dripping particles cannot ignite cotton. V-0: after two 10 second combustion tests on the sample, the residual flame and residual combustion will be extinguished within 30 seconds. Dripping particles cannot ignite cotton. 5vb: after five 5-second combustion tests on the sample, the residual flame and residual combustion are extinguished within 60 seconds. Dripping particles cannot ignite cotton. For block samples, it is allowed to burn through. 5va: after five 5-second combustion tests on the sample, the residual flame and residual combustion are extinguished within 30 seconds. Dripping particles cannot ignite cotton. Block samples are not allowed to be burned through. 2、 Foam type UL94 HbF, HF-1, HF-2 horizontal combustion test lubricate and refuel according to the regulations. Applicable products: foam materials

sample size: 15 pieces (150 ± 5) x (50 ± 1) mm x thickness (both the minimum thickness and the maximum thickness should be provided. When the test results of the maximum thickness and the minimum thickness are inconsistent, the thickness in the middle should also be provided. The interval should not exceed 6mm, and the sample width should not exceed 50mm

Test Method: ul94:1997, ASTM D (foam plastic with serious slip phenomenon in essence), IEC (2003), ISO (soft foam material); Test related introduction: make reference marks at 25mm, 60mm and 120mm of the test piece, apply the flame of the wing top nozzle to the side of the foam placed horizontally on the wire, and apply the fire source for 60s, and measure the combustion rate of the test piece; Evaluation method:

UL 94 HbF: the material burning rate between the two marks of 25mm and 125mm is not more than 40mm/min, or many users of 125mm mark will call to inquire how to install and debug the hydraulic universal material testing machine after buying the machine back, but it does not meet the requirements of UL 94 HF-1 and UL 94 HF-2; UL 94 HF-1: the open burning time of at least four of the five samples in a group is less than or equal to 2S, and the open burning time of any one sample is not more than 10s. After 60mm marking, the sample failed to be damaged. After the ignition source is removed, or after 60mm marking, the combustion time of the test piece shall not exceed 30s, and there is no droplet; UL 94 HF-2: the open burning time of at least four of the five samples in a group is less than or equal to 2S, and the open burning time of any one sample is not more than 10s. After 60mm marking, the sample failed to be damaged. After the ignition source is removed, or after 60mm marking, the combustion time of the test piece shall not exceed 30s, and the molten drop ignites the absorbent cotton. II. UL vtm-0/vtm-1/vtm-2 thin plastic vertical combustion test for film - Fire Test

Test Category: fire test, thin plastic vertical combustion test ansi/ul, Clause 11

1 Sample size

the sample is (200 ± 5) mm long and (50 ± 1) mm wide, and the thickness is the minimum and maximum thickness. If the minimum thickness or maximum thickness test results are inconsistent, samples of medium thickness should also be provided and tested

2. Number of samples

10 samples for each thickness and condition adjustment condition

3. State adjustment

temperature (23 ± 2) ℃, relative humidity (50 ± 5)% for at least 48h

adjust the temperature at (70 ± 1) ℃ for 168h, and cool it in a dryer at room temperature for at least 4 hours before the test

4. Combustion conditions

flame height: (20 ± 1) mm

flame color: blue flame

combustion gas: methane

combustion angle: 90 °

combustion time: (3 ± 0.5) s apply twice

5 Evaluation criteria material classification criteria vtm-0vtm -1vtm -2 afterburning time T1 or T2 ≤ 10s ≤ 30s ≤ 30s of each sample for any state adjustment conditions, the sum of afterburning time (t1+t2) ≤ 50s ≤ 250s ≤ 250s of each group of five samples, the subsequent combustion time of the second flame application of each sample plus smoldering time (t2+t3) ≤ 30s ≤ 60s ≤ 60s of any sample afterburning or smoldering spread to the 125 marking line, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no Vtm-1, vtm-2 level vertical combustion test