At the recent TOEM Forum Council, Ren Mingdang, deputy director of the forum's expert committee, gave an analysis report on the current transmission cable industry. He mentioned that the four major transmission cables in the history of fixed communication can be summarized as three major transmission cable theories, namely, symmetrical cable, coaxial cable, and optical fiber cable. He further pointed out the development trends of these three types of cables and their materials.
The future development of symmetrical cable materials should focus on multiple directions. These include the development of metal-coated fibers, such as metal-coated aramid fibers, which not only have the excellent properties of aramid fibers, such as high strength, high modulus, low density, flame retardant, high-temperature resistance, good flexibility, and small linear expansion coefficient, but also have good electrical conductivity, antistatic and electromagnetic shielding effects, and can be used as shielding components (shielding layer and braided wave-proof sleeve) and signal transmission components for aerospace cables, with a weight of almost less than 2% of the copper braided layer. Due to the good reflectivity of this material to electromagnetic waves and infrared rays, it can be used as a countermeasure against radar interference.
High-tech materials that need to be researched and developed include nitrogen-substituted carbon austenitic stainless steel and super austenitic stainless steel wire reinforcement materials, as well as ultra-fine silver-copper alloy wire, ultra-fine tin-copper alloy wire and other high-grade metal wire materials. Other aspects of innovation include cross-linked ethylene-tetrafluoroethylene copolymer (X-ETFE) materials, high-performance polyimide (PI) film, modified polyester ether, and other high-performance thin insulation materials. For a long time, China's high VA content EVA technology has been highly dependent on imports, facing foreign monopoly and technology blockade, we should find the direction of technological breakthrough, and strive to improve the VA content of EVA in China. Finally, we should pay attention to some special scenarios of cable materials, such as ternary ethylene propylene rubber and chlorosulfonated polyethylene for port machinery cables, and ultra-low temperature resistant materials for polar ship cables.
The development of coaxial cable materials focuses on achieving more innovative results. These include the development of high-quality shielding materials for CATV made of aluminum foil, copper foil, aluminum magnesium alloy wire, copper wire, etc., as well as high-performance RF coaxial cable with high-precision metal wire, metal shielding tape, and composite metal conductor. Of particular interest is the potential significance of the localization of high-strength copper-clad steel and aluminum alloy conductors for the competitiveness of China's coaxial cable industry in the future. Other innovative directions include the development of low-loss RF coaxial cable with microporous polytetrafluoroethylene insulation tape, foamed fluoroplastics, and radiation-resistant silicone rubber materials, which are further processed and modified traditional materials, such as introducing bubbles into fluoroplastics, forming a foam structure, thereby increasing its insulation performance, reducing its weight, and having a certain buffering performance; adding microporous structure to traditional polytetrafluoroethylene (PTFE), which makes it have lighter weight and higher flexibility while maintaining the excellent insulation performance of PTFE; designing traditional silicone rubber with special processes and additives, making it have stronger radiation resistance.
The development of optical rod materials mainly lies in improving the performance of materials. These include the development of high-purity silicon tetrachloride materials suitable for core rods, and the large-scale production of organosilicon (D4), etc. The development of low-refractive-index optical fiber resin, environmentally resistant high-performance coating resin, such as high-temperature-resistant resin, low-temperature-resistant resin, radiation-resistant resin, high-strength high-modulus resin, etc., and the localization of large-size preform quartz sleeve and liner.
There are many and varied types of optical cable raw materials, and their development directions are also different. Polyethylene materials should develop low-shrinkage, high-thermal-conductivity polyethylene polymer and polyethylene insulation materials suitable for UV cross-linking. Fiber paste cable paste mainly includes flame-retardant and environmentally friendly optical fiber cable filling paste, OPGW, 0PPC high-performance hydrogen-absorbing fiber paste, irreversible preheating expansion optical fiber paste, and other innovative materials. Other new functional materials, such as high-strength high-modulus aramid fiber, water-blocking steel (aluminum) / plastic composite tape, etc., also provide more possibilities for the future application of optical cable.
In the current development of the transmission cable industry, symmetrical cable, coaxial cable, and optical fiber cable will continue to be the key technology areas. By continuously promoting material innovation and technology research and development, we can better adapt to the evolving communication technology needs and the ever-changing market environment. The exploration of innovative directions not only helps to improve the performance and stability of transmission cables but also lays a solid foundation for the sustainable development of China's communication industry. In the future, we look forward to more cross-border cooperation and technological breakthroughs, bringing more broad development space for the transmission cable industry.
