In order to overcome the shortcomings of the low heat resistance of muscovite and phlogopite mica, Chen Yunsheng of Guangzhou Tianhe Yingke New Material Products Co., Ltd. took the lead in inventing A-grade refractory synthetic mica tape, which passed the UL test in the United States and was awarded the International Ain by the United States. The Stein Invention Gold Award and the patent right granted by the China Intellectual Property Office are the pride of the Chinese people. In 1994, the synthetic mica tape was first tested successfully in Guangzhou Cable Factory, and then gradually promoted and applied to the whole country, and has been exported to Europe, America, South Korea and Southeast Asia.

Synthetic mica is an artificial mica with large size and complete crystal form synthesized under normal pressure conditions by replacing hydroxyl groups with fluoride ions. Synthetic mica tape is made of mica paper made of synthetic mica as the main material, and then paste the glass cloth on one or both sides with an adhesive. The glass cloth that is pasted on one side of the mica paper is called "single-sided tape", and the one that is pasted on both sides is called "double-sided tape". During the manufacturing process, several structural layers are glued together, then oven-dried, then wound up, and cut into tapes of different specifications. In the manufacture of synthetic mica tapes, the quality of the glass cloth and adhesive is important. The quality of the glass cloth directly affects the mechanical strength of the product, and the adhesive is the key factor to ensure that the tape does not delaminate. The quality of domestic adhesives is quite different from that of imported adhesives, so the cost of mica tapes is also different.

In addition to the characteristics of natural mica tapes: small expansion coefficient, high dielectric strength, high resistivity and uniform dielectric constant, the main feature of synthetic mica tape is high heat resistance level, which can reach A-level fire resistance level (950-1000). ℃), while the natural mica tape can only reach grade B (750-800 ℃), even if it is wrapped with three layers, it is difficult to reach grade A. This is a well-known fact. At the International Cable Expo held in Atlanta, USA a few years ago, synthetic mica tapes attracted much attention from various countries, which has fully demonstrated the status of synthetic mica tapes. Some people say that the reasons why several large foreign mica tape manufacturers only produce natural mica tapes are that the environmental protection regulations in Europe and the United States are strict (this will be discussed below), and the second is that natural mica tapes can meet the requirements of fire-resistant cables in Europe and the United States. standard.

Looking through the cable product samples in Europe and the United States, there are almost no reports on Class A fire-resistant cables. The author once negotiated with a company in Europe. They took out a sample of fire-resistant cable made of film-reinforced mica tape. The fire resistance grade is B. It is used in the North Sea oil field. They said: "It is difficult to achieve A-level with this mica tape." . Since there is no A-grade mica tape in the foreign market, of course, the B-grade natural mica tape has to be used, which is normal. In this case, as an Italian company said, "some profiteers use a pretense to deceive users". In addition, the synthetic mica tape is softer than the natural mica tape, wrapping well, and has higher tensile strength. It is an ideal fire-resistant tape for fire-resistant wires and cables of 1mm2 and above. Over the past few years, many key projects in China have specified that Class A synthetic mica tapes must be used to manufacture fire-resistant cables.