Is Polyethylene a Better Outer Sheath Material for ADSS Optical Cables?
As an engineer from Hengtong, I've been involved in numerous ADSS optical cable projects, and during this process, I've accumulated a wealth of experience and insights regarding the selection of outer sheath materials. Today, I'd like to discuss this topic with you all.
ADSS optical cables are typically used in the strong electric field environment near high-voltage transmission lines. In such a setting, electrical tracking easily occurs on the surface of the cables. The LSZH (Low Smoke Zero Halogen) material, which is commonly considered, has relatively weak resistance to electrical tracking and struggles to effectively safeguard the cables from the damage caused by electrical tracking. In contrast, the anti-tracking polyolefin sheath or black polyethylene sheath shows clear advantages. They can better meet the requirements of ADSS optical cables in high electric field environments, thus ensuring the stable operation of the cables more reliably in this regard.
When it comes to mechanical properties, there are several aspects that demand our attention. During the installation of ADSS optical cables, especially in long-distance overhead laying and complex terrains, the cables need to bear certain tensile forces, which means high requirements for the tensile strength of the sheath. Regrettably, the LSZH material often fails to meet the mechanical requirements for ADSS optical cables during long-span overhead installation in terms of tensile strength. Traditional materials like polyethylene, however, perform outstandingly in tensile strength and can better protect the optical fibers and other structural components inside the cables, enabling the cables to remain robust and durable under various complex stress conditions.
Moreover, the ability to resist lateral pressure is also crucial. In the process of installation and use, ADSS optical cables may face external lateral pressures due to factors like wind and vibration. The LSZH material has relatively limited resistance to such pressures. Over time, under the influence of these pressures, the cables may deform and the optical fibers may be damaged, which will ultimately affect the transmission performance and service life of the cables. Traditional materials like polyethylene, on the other hand, have better performance in resisting lateral pressure and can handle these external pressures more effectively.
Cost is another significant factor that we cannot ignore when choosing outer sheath materials. The production process of the LSZH material is relatively complicated, and its raw material cost is relatively high as well. As a result, the manufacturing cost of ADSS optical cables with LSZH sheaths increases significantly. In the construction of large-scale power communication networks, cost control is of utmost importance. Using traditional materials like polyethylene with relatively low costs can not only guarantee the basic performance of the cables but also reduce the construction cost effectively, making the project more economical.
Finally, let's consider the adaptability to the installation environment. ADSS optical cables are usually used outdoors for a long time and have to endure various harsh climatic conditions such as high temperature, low temperature, ultraviolet radiation, and humidity. When exposed to the outdoor environment for a long time, the LSZH material is prone to aging, cracking, hardening, or softening, which will undoubtedly affect the protective performance of the sheath. In contrast, materials like polyethylene, after special formulation and treatment, possess good weather resistance and can adapt to different climatic environments with ease. Additionally, in areas with severe industrial pollution or in coastal areas with corrosive salt fog, the sheath of the optical cable needs to have good chemical corrosion resistance. The LSZH material is inferior to materials like polyethylene in resisting the erosion of certain chemical substances. Once the sheath is damaged, the performance of the optical cable will surely be affected.
Based on the comprehensive consideration of all these factors, from the perspectives of ensuring the performance and service life of ADSS optical cables as well as controlling costs, is polyethylene a better choice as the outer sheath material for ADSS optical cables compared to the LSZH material? In most cases, I think the answer is yes. Of course, the specific choice still needs to be determined comprehensively according to actual engineering environments, budgets, and other factors. But I hope my analysis can provide you with some valuable references when choosing the outer sheath material for ADSS optical cables.