I am afraid no one in the world will ever deny the perfluorinated plastic. American scientists have also said that the decomposition of fluoroplastics (mainly FEP), hydrofluorocarbons (HF), is also much more toxic than the degradation products of PVC (HCL). They put the decomposition of fluorine plastic products HF as a "phosgene", belong to the category of highly toxic substances. However, all countries in the world, especially the United States, are still using fluoroplastics to manufacture heat-resistant toxic cables, and little consideration is given to their toxicity. The environmental science circles said that they are helpless. Some people think that the evaluation of fluoroplastics can not only be assessed on environmental requirements? Fluoroplastic is indeed a very good cable material, for example: (1) Has a very good performance? Known as the "plastic king"? In the special occasions more applications? In the military? Aerospace? Chemical? Iron and steel industry, metallurgy and petroleum are widely used? (2) high temperature (HF bond can be large)? Not easy to decompose? Many non-polar materials? Dielectric properties are better? Can be used for high frequency communication transmission? Corona resistance is better? Insulation performance is also very good? High stability? Not easy to corrosion? Flame-retardant performance is better (contains a large amount of fluorine element). (3) Environmental analysis. Some people have analyzed, from its decomposition products to points? HF is its essential decomposition products? Its toxicity is indeed much stronger than the HCL. The toxic gas used in the Japanese subway poisoning incident in the 1980s was HF (which was made by reacting NaF with acid solution and heating the "Aomala truth teaching" by dropping the alcohol stove)? More than 700 people were poisoned. HF has HF decomposition above 450 ° C, not what people call it at 800 ° C, but only because of its good stability and very little decomposition, and at 220 ° C it has the same performance as PVC at 220 ° C. Flame Retardant? Fluorine plastic flame retardant? No need to add flame retardants can have a higher flame retardancy, in terms of combustion performance? In the open flame temperature is higher? Easy to burn? High temperature is a local What is the difference between this and the ambient temperature? Under normal circumstances the ambient temperature does not reach 800 ℃? There is no human death. Fluoroplastics are less stable at temperatures below 320 ° C (FEP), and are environmentally friendly. Some people think that, regardless of FEP? PTFE? PFA? F40 and PVDF as fluoroplastic? Has made a very distinguished contribution to the economic development of mankind. At present, in many applications, it is obviously not too late to use other eco-friendly materials instead of them. Now there is no such kind of material as fluorine plastic can focus so much excellent performance? And very environmentally friendly. Environmental protection should have a standard and requirements? Excessive environmental protection is absolutely impossible? The substance of the Earth we live in can not be changed. The human body also contains indispensable elements such as chlorine and fluorine. It is a prejudice to use the environmental requirements to evaluate the fluorine material. So far, no country in the world of military products can abandon the fluorine material. US aircraft extensive use of high temperature radiation cross-linked polyethylene cable instead of fluorine plastic cable? However, more than 200 ℃ for the use of fluoroplastic cable? Only F40 used in the fluorine content is reduced, the density is smaller only . Ordinary cable and fluorine plastic insulated cable performance comparison? (1) The overload capacity and short-circuit heat capacity of common cables (such as VV? YJV? KVV? KYJV and other types of cables)? Long-term operating temperature is 70? Or 90?? Can not withstand high ambient temperature? Shrink? Poor thermal cycling? Affects circuit safety. Fluorine plastic insulated cables long-term allowable working temperature is above 200 ℃? Not only can work in high temperature environment? And can greatly improve the cable carrying capacity. (2) ordinary cable laying in the place of oil and steam? Due to the presence of oil and chemicals? The insulation will swell? Aging? Cracking? Loss of mechanical and physical properties caused by wire scrap. Fluorine plastic insulated cables due to fluoroplastic acid and alkali and various chemicals? Therefore, the product has excellent corrosion resistance. (3) Ordinary cable insulation mechanical strength is relatively low? Easy to be knocked? Bumps caused by power supply accident. Fluorine plastic insulated cables high strength? Hardness? To prevent mechanical damage. (4) When the ordinary cable has moisture intrusion? Insulation dielectric loss increases? Insulation resistance decreases? Affect the wire life. Fluorine plastic insulated cable structure is solid? Insulation and conductor close together? Can effectively prevent the external water? Oil and moisture infiltration. (5) Ordinary cable flame retardance is poor? Adding flame retardants? Electric insulation reduces? Burning a large number of toxic and harmful fumes? Environment? Equipment and the lives of people have a tremendous risk. Fluorine plastic insulated cables high oxygen index, up to 95%? Almost non-flammable? Flame-retardant properties are unmatched by other materials. When PVC cables burn, hydrogen chloride and dioxide gas are emitted and identified by Greenpeace as "science-known toxic synthetic chemicals." When the FEP cable burns, it releases a colorless, odorless, but hydrogen fluoride that is more toxic than hydrogen chloride. Some tests show that there is another dangerous gas in the FEP smoke. This super-toxin has never been correctly recognized by mankind. Now its research has stopped. However, some people think that this super-toxin is only an experimental product and does not exist in reality. Fluoroplastics are mainly produced in the United States and South Korea and are the leading products of some large chemical companies. Toxicity is basically what they say. However, the European scientific community has different voices. Anderson Laboratories in Europe used the method known as the Pittsburgh test, which is published by the University of Pittsburgh, to measure the toxicity of fluoroplastic cable sheaths. During the test, a certain amount of fluoroplastic insulation was burned and the smoke was passed through the catheter to the space where 4 white rats were sitting until 2 rats died. The weight of the insulating layer burning at this time is one LC50 toxic unit, meaning that so many layers of insulation will kill half of the test animals on combustion. Through this test, it was found that the toxicity of FEP cable is 1.5 times that of PVC cable and 5 times that of halogen-free cable. Proponents of Fluoroplastics (FEP) argue, however, that the test is academic, because the test environment is not a real fire scene and when it reaches the temperature required to release those toxic gases in the building, no matter what The temperature is too high (800 ℃) and already died. This argument is obviously untenable. In the U.S. "9.11" incident, the World Trade Center building caught fire. Why it has been a long time since the death toll caused by the toxicity of wires and cables caused much loss.