With the development of society, the scale of the city has been expanding, high-rise buildings have been emerging, and the number of important buildings has been increasing. The fire caused by the electric line, especially the huge fire accident, endangers the safety of life and property, and some fatal and huge fire, often causes a series of social problems and accountability. Once the fire happens, rescue is very important, fire pump, fire smoke exhaust, emergency lighting, fire elevator and other rescue equipment become the protection of people's escape, and these protection "lifeline" is the fire-proof cable. Due to the frequent occurrence and serious consequences of fire, more and more attention has been paid to the performance and testing of fire-resistant cables. Table 1 gives examples of the structure and standard test conditions of fire-resistant cables in some countries and regions, from Table 1, we can see the different requirements of GB, IEC, BS, AS for the test performance of fire-proof cable. China fire-resistant cables mainly implement the national standards, fire resistance requirements through BS 6387 or BS8491 fire-resistant + vibration + spray fire test.
At present, the fire-proof cables on the market are mainly divided into two categories from insulating materials, namely, magnesium oxide insulated fire-proof cables and mica-mineral compound insulated fire-proof cables, the common custom is respectively called the rigid fireproof cable and the flexible fireproof cable. Because of the difference of structure design and material technology, the two kinds of cables have their own characteristics and need to be improved. As a rigid fireproof cable, it has many advantages, such as high temperature resistance, radiation resistance, long life and good earthing, etc. . The other category is flexible fireproof cable with twisted conductor + mineral composite insulation + Metal Sheath or fireproof mud composite sheath, theoretically speaking, tubular metal or metal sheathed fireproof cable after mechanical deformation through rolling, the flexibility is mainly relative to solid conductors, and the flexibility of fireproof cables with fireproof mud insulation is limited by the hardness of the fireproof mud. Compared with conventional cables, these fireproof cables need special accessories and technology in connection, and it is more difficult to realize pre-branching. Their branch joints are often connected by branch boxes, except for complicated installation, construction strength, fire performance, joint performance and sealing moisture performance is also uneven.
We study the structure and material of the fireproof cable deeply, and take the flexibility, fireproof safety and construction convenience as the research direction, develop a kind of flexible fireproof cable, it has passed GB, IEC, BS and AS tests, and is a kind of truly flexible fireproof cable. On this basis, we developed the prefabricated branch type environmental protection fireproof cable. This prefabricated branch type fireproof cable has low manufacturing cost and not only retains the advantages of the traditional fireproof cable, the utility model also overcomes the problems of moisture absorption of the fire-proof layer of the general fire-proof cable and the poor flexibility of the cable, and is convenient to install and lay.