As the global emphasis on public safety, environmental protection and sustainable development continues to increase, low smoke zero halogen (LSZH) flame-retardant polyolefin cable materials have become the core protective layer materials in key fields such as rail transportation, new energy (photovoltaic/wind power), high-rise buildings, and nuclear power plants. However, due to their strong moisture absorption properties, LSZH cable materials tend to cause electrical performance degradation over time, which may lead to leakage or discharge risks, thereby threatening the stability and safety of the long-term operation of the cables, and contradicting the global requirements for public safety.
Through research, it has been confirmed that the water absorption can be effectively inhibited through the following three aspects: Firstly, by using the mass method to regulate the types of flame retardants to reduce the polarity of the cable material surface; Secondly, choosing high crystallized or low polarity resins to reduce the inherent water absorption of the material; Thirdly, optimizing the irradiation cross-linking process, that is, adjusting the cross-linking density of the cable material to reduce the water absorption of the material, thereby improving the water resistance of the material. Under the condition of low water absorption rate, the three-dimensional network structure formed by irradiation cross-linking can restrict the movement of molecular chains and reduce internal voids, resulting in a higher and more stable breakdown strength. This enhances the electrical performance and long-term reliability of the cable.
