Flame retardant cable

Flame retardant cable refers to the cable that the flame spread is only within the limited range after the test flame source is removed after the sample is burned under the specified test conditions, and the residual flame or burning can be extinguished within the limited time. The basic feature is that in case of fire, it may be burnt out and cannot operate, but it can prevent the spread of fire. Generally speaking, in case of wire fire, it can limit the combustion to a local range without spreading, protect other various equipment and avoid causing greater losses.

Application field of flame retardant cable

The meaning of flame retardance: under the specified test conditions, the sample is burned, and after the fire source is removed, the flame spread on the sample is only within the limited range and extinguishes itself, that is, it has the ability to prevent or delay the occurrence or spread of flame. The combustion of wires and cables is caused by external heating and produces flammable gases. In order to achieve the purpose of flame retardance, the three factors that cause combustion must be suppressed, namely, flammable gases, heat and oxygen. Therefore, the general method used for flame-retardant wires and cables is to add halides and metal oxides containing halogens into the sheath material, which is an excellent method to evaluate from the perspective of flame retardancy. However, because these materials contain halogens and release a large amount of smoke and hydrogen halide gas during combustion, the visibility in case of fire is low, which greatly hinders the safe evacuation and fire fighting of personnel, People are more suffocated by toxic gases. In addition, once the hydrogen halide gas reacts with the water in the air, it will generate "hydrogen halide acid", which will seriously corrode the instruments, equipment and buildings and cause "secondary disasters". With the continuous improvement of science and technology, the problem of flame retardance has been further developed from halogen flame retardance in the past to low halogen and halogen-free flame retardance.

Advantages of flame-retardant cable

The characteristic of flame-retardant cable is to delay the spread of flame along the cable and prevent the fire from expanding. Because of its low cost, it is a large number of cable varieties used in fireproof cables. Under the condition of single cable or bundle laying, the flame spread of the cable can be controlled within a certain range when it is burning, so it can avoid major disasters caused by fire and delay, thus improving the fire prevention level of the cable line.

Difference between flame-retardant cable and fire-resistant cable

It is easy for ordinary people to confuse the concepts of flame-retardant cables and fire-resistant cables. Although flame-retardant cables have many advantages that are more suitable for chemical enterprises, such as low-halogen, low-smoke flame-retardant, etc., in general, fire-resistant cables can replace flame-retardant cables, while flame-retardant cables cannot replace fire-resistant cables. Their differences are mainly as follows: 1. Difference in principle: the principle of fire-resistant cable is different from that of flame-retardant cable. The flame retardant principle of halogen-containing cable is based on the flame retardant effect of halogen. The flame retardant principle of halogen-free cable is to extinguish the fire by reducing the temperature of the water. The fire-resistant cable is based on the fire-resistant and heat-resistant characteristics of the mica material in the fire-resistant layer to ensure that the cable can work normally in case of fire. 2. Difference in structure and material: the structure and material of fire-resistant cable are also different from that of flame-retardant cable. The basic structure of flame-retardant cable is: (1) the insulation layer is made of flame-retardant materials; (2) the sheath and outer sheath are made of flame-retardant materials; (3) Wrapping and filling are made of flame retardant materials. Fire-resistant cables usually add a fire-resistant layer between the conductor and the insulating layer, so in theory, a fire-resistant layer can be added to the structure of the flame-resistant cable to form a flame-retardant and fire-resistant cable, but it is not necessary in practice. Because the fire-resistant layer of fire-resistant cable is usually wrapped directly on the wire with multi-layer mica tape. It can withstand long-term combustion, even if the polymer at the place where the flame is applied is burned, it can ensure the normal operation of the line.