Synthetic mica tape is made from fluorphlogopite raw material. The structural formula of phlogopite is: Kmg3(AISi3O10)(OH)2, and the structural formula of fluorphlogopite is: Kmg3(AISi3O10)(OH)F2. From the perspective of molecular structure, the difference between the two is that the former contains OH ions, and the latter contains OH ions. Mica contains F ions, and its fluorine content is 8.89%. It is precisely because synthetic mica contains F ions that the heat resistance level is greatly improved. The characteristics of synthetic mica containing fluorine are also foreign film-reinforced phlogopite tapes. It is an excuse for manufacturers to make a fuss for the needs of competition. In fact, for fire-resistant cables, fluorine content is not a key factor. The question is how much fluorine is released when the cable is burned, and whether the released fluorine reaches a lethal amount. A foreign businessman just said that a "polymer film" was used in the film-reinforced phlogopite tape, but did not mention whether the polymer contained fluorine and other ingredients, which was puzzling. It was only suggested in the product manual. Wear gloves when handling the film and wash your hands with detergent afterwards. This shows that the film-reinforced phlogopite tape is a toxic component. In the process of manufacturing synthetic mica tape with fluorphlogopite, after grinding and high temperature baking, the fluoride ions in the finished mica tape have been partially volatilized, otherwise the UL laboratory in the United States will not judge the toxicity of synthetic mica tape "negligible", Europe and the United States with strict environmental protection regulations will not import synthetic mica tapes.

As a scholar in northern Europe said; "It is impossible to be absolutely non-toxic. Most organic combustibles will release Co when they are burned. Can we say that they are non-toxic?" nation. For example, fluoroplastics are still widely used in the United States to manufacture wires and cables, and fluoroplastics release much more fluorine when burned than synthetic mica tapes. In the United States, fluoroplastic wires and cables are widely used in various important fields including navigation, aviation, and aerospace, and even fluoroplastic wires and cables are used in the Capitol. UL Laboratories has never determined which fluoroplastics are of negligible toxicity. Now, the domestic industry has also called for the vigorous development of fluoroplastic wire and cable. Who can comment on the merits and demerits of fluoroplastic insulation? Therefore, there is really no need for us to fool ourselves by putting gold on Americans' faces on the grounds that synthetic mica tapes "contain fluorine". Even though a halogen-free polymer is basically composed of C=C bonds, will there be no Co evolution when burned? Therefore, it is not as good as the others to attack synthetic mica tapes, and the "toxicity" they attack is untenable. As for whether synthetic mica tape can be used in halogen-free fire-resistant cables, since the UL laboratory has determined that its toxicity is "negligible", of course it can be used.