In recent years, more and more fire-resistant cables have been used, mainly because users have recognized the performance of this cable. At the same time, the number of manufacturers of this cable is also increasing. It is very important that the quality of fire-resistant cables is guaranteed and long-term stability. of. Under normal circumstances, the optical cable manufacturing department of Anhui Tiankang Group is first trial-producing a section of products, submitted to the relevant national detection agencies, and after obtaining the detection report, it will conduct batch production. A few cable manufacturers have created their own fire-resistant tests. In the detection room, as we all know, the fire resistance test is based on the inspection of the results of the cable technology produced. The same process plan and the cable performance produced at different times have certain differences. For fire-retardant cable companies, if fire-resistant cables are used, Fire resistance experiment pass rate is 99%, then there is a 1% risk of safety hazard in the fire-resistant cable, which is 100% dangerous for the user, and how to improve the passing rate of the fire-resistant cable fire resistance test from the raw material , Conductor selection, production process control, etc. are described as follows: 1. Some manufacturers use copper-clad aluminum conductors as cable conductor cores, but conductors for fire-resistant cables cannot use copper-clad aluminum conductors and use copper conductors. 2. For circular cores with axial symmetry, the mica tapes are tight in all directions after wrapping. Therefore, for the fire-retardant cable conductor structure, a round compaction conductor should be used. The reason is as follows: Some users proposed that the conductor is a stranded flexible structure conductor, which requires the company to change from the reliability of the use of the cable to the user's circular pressing conductor. The soft structure of the beam line, the multiple stranding can easily cause mica tape damage, as a fire-resistant cable Conductors are not desirable, but some manufacturers think that users need what kind of fire-resistant cables, manufacturers should meet the needs of users, I think users are not very clear about the relevant details of the cable, the cable is closely related to the lives of people Therefore, cable manufacturers must clearly explain relevant technical issues to users. The fan-shaped conductor is also not suitable, because the pressure of the winding of the mica tape around the fan-shaped conductor is unevenly distributed. As shown in the figure, it can be seen from the figure that the stress at the three fan-shaped corners of the fan-shaped core around the mica tape is the largest. Because mica is a sheet-like silicate polymer, its interlayer molecular attraction is far weaker than that of the s1-O covalent bond in the crystal. The layers are easy to slide and adhere to silicon, but the adhesive strength is also low, and they are easily peeled off and cracked when the external force is scraped or squeezed. Especially when the fan-shaped structure is used, the core after wrapping is passed through the guide wheel and points. When the poles and cables are routed to the edges of the side plates of the tooling wheels, and the extruded insulation of the subsequent processes enters the cores, they are easily scratched and bumped, which leads to a decrease in electrical performance. In addition, the cross-sectional circumference of the sector-shaped conductor structure is viewed from a cost perspective. The length is greater than the perimeter of the circular conductor, which increases the precious material mica tape, although the diameter of the cable of the circular structure increases. PVC sheathing material usage increased, but compared to the total cost of product materials, the overall cost of the round structure of the cable is still saving. Based on the above description, from the perspective of technical and economic analysis, it is preferable that the conductor of the fire-resistant power cable has a circular structure. 3. Mica comes with three types of synthetic mica, phlogopite, muscovite, their respective quality performance is the best synthetic mica, muscovite is the worst, for small size cable must choose synthetic mica tape to wrap, mica tape layering can not For use, long-term storage of mica tape is easy to absorb moisture, so the temperature and humidity of the surrounding environment must be taken into account when storing the mica tape. 4. When using mica tape wrapping equipment, the stability performance should be good. The wrapping angle should be wrapped around 300--400, and the mica tape should be wrapped evenly and tightly. All guide rollers and rods that touch the equipment must be smooth. Lines are neat and the tension is not too great. The side plates and cylinders of the tooling wheels are flat and smooth. Methyl Vinyl Silicone,High Qulaity Vmq Rubber,Silicone Liquid Rubber,Methyl Vinyl Silicone Liquid Rubber Zhejiang Sucon Silicone Co.,Ltd. , https://www.hycsilicone.com
How Fire Resistant Cables Meet Fire Resistance