How many levels are there in the classification of PP fireproof materials?
The level of fireproof materials: A-level: Non-combustible building materials have rare chance to burn. A1-level: Non-combustible materials, no open fire A2-level: Non-combustible materials, smoke should be tested and qualified. B1-level: Fire-retardant building materials: Fire-retardant materials are good at resisting flame. It is difficult for them to burst into fire when coming across open fire in the air or at high temperature. It will not quickly get wilder and when the fire source removes, it will be extinguished immediately. B2-level: Combustible building materials: Combustible building materials can play a certain role in preventing combustion. It will immediately burst into flames when coming across open fire or at high temperature, and will lead to fire spreading, such as wooden pillars, roof frames and beams as well as stairs. B3-level: Inflammable building materials are highly flammable with no flame retardant ability, fire risk is high.
PP fireproof materials level V-0: After two 10-second fame tests on the sample, the flame extinguishes within 30 seconds. Inflamer can not drop. V-1: After two 10-second flame tests on the sample, the flame extinguishes within 60 seconds. Inflamer can not drop. V-2: After two 10-second flame tests on the sample, the flame extinguishes within 60 seconds. Inflamer can drop.
