Cable sheath containing halogen and do not contain halogen characteristics

Information Source:Huadong Cable Group-Zhengzhou Hongliang Cable Co., Ltd24 fiber  Release date:13/11/2013

Most parts of the world laying power (ABC cable)and communication cable are containing halogen, this kind of cable in the combustion would send out a poisonous fog chemicals. In the fire, including halide cable will produce acidic gas, to the detriment of the person's nose, mouth and throat, smoke still make the victim easily lost the direction, and difficult to get away from the scene of the big fire. To realize the potential harmfulness, some European countries have halogen free cable as power and communication cable standard.

But, the United States national electrical code but clearly stipulates: network must use has containing halogen cladding exceed five categories or six kind of UTP (not shielded twisted-pair cable) network cable. This is because, including halide cable although has important defects, but halogen itself has a strong flame resistant property and high flash point, if cable don't fire or it is difficult to fire, so will not cause combustion, thus will not send out a toxic smoke.

In fact, (PVC insulated power cable )some fire is because cable itself power on a long time lead to overheat and cause. Halogen free cable for ignition temperature is low, so are more likely to cause fire, and halide insulating layer can better prevent cable spontaneous combustion. However, if the cable has been in a fire, so its produce smoke can cause life poisoning. These contradictions in halogen applications has been the focus of debate industry.

Support containing halogen cable of the main application on behalf of the company, the United States federal company and Goodrich and other companies. Against containing halogen cable application mechanism more expect more able to persuade NFPA (American fire protection association) modify the current standard, stop using containing halogen cable or allowed in the building ventilated place use contain halogen cable.

Halogen free cable advocates tried to amend the standard, but so far without success. The main reason is that main line slot cable spontaneous combustion sexual channeling layer combustion make people not easy for regional fire control, which cause the whole building fire, and low flash point susceptible to fire. Another main reason is no evidence halogen free cable it can save a life (because the interior of the building still exist a lot of other ornamental also contain halogen).

At present the relevant international standards in cable focused on three questions is: fire sex (cable burning speed), smoke density (produce much visible smoke) and toxicity (to human body to produce much damage). The United States fire standard involves only the first two questions, but it is in use on a more extensive and strictly, to meet the standards must be added to the cable insulation layer will halogen polymer, the PVC cable containing chlorine, and FEP (Teflon fluoro fairy Teflon) cable containing fluorine. FEP strong fire resistance, in burning smoke before disintegration can stand up to 800 ℃ above temperature, it is usually halogen free cable highest can bear 150 ℃ high temperature to several times, and at the same time, FEP is also a kind of efficient insulator. Therefore, FEP is very suitable for making high speed data transmission of the cable, is now widely used in ventilated place over 5 kinds of UTP key factors. In a high-rise shaft and other ventilated place, FEP cable has a large number of replaced the PVC cable.

European some country's standard is different, in order to conform to the strict anti toxicity standards, cable manufacturers do not use halogen, acting with metal to join polyethylene and poly (ene cable insulation layer within the. When heated, the cable only send out a toxic small visible gas. But, this kind of halogen free cable fire prevention performance as containing halogen cable, and the insulating layer will soon combustion. Therefore, halogen free cable fails to meet the strict American fire standards, to achieve ventilation and air draft place class other fire requirements, you have to add too much metal hydroxide, thus affecting the cable performance and technical requirements.

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