Qiaopu special The Mechanism of wire and cable fire

1, fire-retardant mechanism
(1) In the heat off under the action of response, in the condensed phase flame synthesis, and this synthesis process is endothermic, so that the temperature rise in the condensed phase can slow down, slow down the speed of data synthesis.
(2) flame retardant heat synthesis, the release of the so-called free radicals chain reaction inhibitor, the flame reaction branching chain reaction infix, slowing the rate of gas phase reactions.
(3) catalyzed solid phase synthesis of condensed phase products of thermal and coking layer or foam layer of the composition, layered crust of these obstacles to enhance the heat transfer effect.
(4) under the action of the heat, flame retardants showed endothermic phase-change, stop the physical nature of the temperature inside the condensed phase. On the flame retardant properties of wire and cable specifications match multiple experiments, including IEC332-3, IEEE383 are two typical experimental specification into the beam off, our country specification is equivalent with IEC332-3.

2, fire mechanism
In wire and cable insulation and sheathing materials to participate in some kind of additive in the lower polymer heat, avoid synthetic polymer insulation and sheath materials or promote the maintenance of carbonized layer composition; the second is at the core layer of conductive glass mica with other inorganic insulating materials, so this cable can be in the off line environment to ensure the normal power supply operation for some time, the product after the fire at 750 ℃ ​​out 3 hours processing frequency voltage 1000V applied without producing breakdown. Fire-resistant wire and cable in China at present is divided into A, B two, mainly based on GB/T12666.6 (such as school IEC60331) Rules experimental approach.

3, fire cable mechanism
As the inorganic flame retardant, primarily used to absorb the effects of the metal hydrate them with fire retardant, in this respect representative of the metal hydrate with AL (OH) 3, Mg (OH) 2, 2Zn.3B2O3.3.5 H2O and so on.
Al (OH) 3 and Mg (OH) 2 as a flame retardant, are operating at high temperatures because they can explain the chemical separation under the water (Al (OH) 3 was 34.6%, Mg (OH) 2 to 31%), (see reaction type 4-1 and 4-2), and this reaction should be endothermic synthesis reaction, it can restrain the polymer out.