PVC (polyvinyl chloride)
Superior mechanical properties, generally good electrical properties, relatively stable to the atmosphere, acids, alkalis, and organic chemicals, and have certain corona resistance, moisture resistance, non-flammability characteristics, simple processing, low cost, and are widely used in insulation and sheathing.
It is a milky white plastic, waxy and transparent, and is an ideal insulation and sheathing material for wires and cables.
Advantages: ①Excellent electrical performance. High insulation resistance and electric strength. In a wide frequency range, the dielectric constant and dielectric loss tangent are small, and it is not affected by frequency changes. As an insulating material for communication cables, it is an almost ideal medium. ② Good mechanical properties, flexible, strong and tough, good tolerance. ③ Good aging resistance, low temperature cold resistance and chemical stability. ④ Good water resistance and extremely low water absorption. ⑤ High air permeability, light specific gravity, good processing performance, not easy to decompose, etc.
Disadvantages: The melting temperature is low (140~160°C). In the event of an accident, short circuit or severe overload, it will cause damage to the line due to polyethylene melting and flowing.
XLPE cross-linked polyethylene
Through chemical or physical methods, the double bonds in the chain macromolecules are opened and connected with the double bonds of other macromolecules to form a three-dimensional, interconnected molecular structure that is cross-connected. After cross-linking, polyethylene changes from thermoplastic to thermosetting material, with greatly improved physical and mechanical properties and significantly improved thermal properties.