The electrical insulation and moisture resistance properties of polypropylene have made it a key material in the electrical and electronics industries. From power and communication cables to various insulating components, polypropylene is used as a reliable filler and separator material. In this article, we explore the main applications of polypropylene in the electrical industry, its technical properties, advantages and disadvantages, and its future outlook.

Main Applications of Polypropylene in the Electrical Industry

• Filler in Cables: In multi-core cables (such as low-voltage power or telecommunication cables), the empty spaces between conductor strands are often filled with polymeric yarns or tapes to maintain a round shape and hold the conductors firmly in place. Polypropylene is an ideal choice due to its light weight, good thermal and chemical resistance, and ability to prevent conductor abrasion. This enhances the cable’s durability and lifespan.
• Separator and Labeling Yarn: Some cables include thin yarns for separating layers or marking specific parts. For example, in fabric-covered cables, polypropylene yarn can act as a separator between layers or as a marker thread. Its flexibility and compatibility with other cable materials make it suitable for such auxiliary roles.
• Ripcord in Cables: A ripcord is a strong thread placed under the cable jacket that allows technicians to easily cut through and remove the outer sheath. Thanks to its smooth surface and low friction, polypropylene performs excellently as a ripcord—it cuts through PVC or polyethylene jackets smoothly without breaking, aided by its good tensile strength.
• Insulating and Binding in Coils: In transformers and small electric motors, insulating yarns are used to tie or bind wire coils together. Polypropylene, with good dielectric strength and low moisture absorption, works well for this purpose in low-voltage equipment. Although glass fiber tapes are preferred for high-temperature applications, polypropylene suffices for standard electrical environments.
• Insulating Components: Polypropylene is also molded into various insulating parts such as fuse holders, supports, and insulating bases. In film capacitors, thin polypropylene films are used as the dielectric layer, particularly in high-voltage applications.

Technical Properties of Polypropylene in the Electrical Industry

• Excellent Electrical Insulation: Polypropylene has a low dielectric constant, making it an excellent insulator against electric current. It prevents leakage currents and short circuits inside cables—an advantage over traditional materials that might absorb moisture and become conductive.
• Resistance to Water and Chemicals: Polypropylene does not absorb water and acts as a barrier against moisture propagation inside cables. It also withstands oils, acids, and chemicals found in industrial environments—ideal for underground or submarine cables exposed to seawater and minerals.
• Lightweight and Flexible: Polypropylene-based materials are lightweight and do not significantly add to cable weight. They also bend easily, maintaining flexibility during installation through conduits or cable ducts.
• Low Toxic Emission During Fire: Unlike halogenated plastics like PVC, polypropylene does not emit highly toxic gases (e.g., hydrogen chloride) when burned. For this reason, it’s recommended in LSZH (Low Smoke Zero Halogen) cable standards, improving safety in case of fire.
• Compatibility with Cable Manufacturing Processes: Polypropylene’s relatively low melting point makes it well-suited to cable extrusion processes. It withstands the heat of the extrusion without damage and can even fuse slightly to the jacket, enhancing cable integrity.

Advantages and Disadvantages of Polypropylene in the Electrical Industry

Advantages of Polypropylene in the Electrical Industry

• Longer Cable Lifespan: Polypropylene fillers and separators prevent deformation and conductor entanglement, extending cable durability.
• Ease of Installation: Polypropylene ripcords simplify sheath removal, while lightweight construction aids transport and handling.
• Cost-Effective: Compared to high-performance materials like aramid (Kevlar) or Teflon, polypropylene is much more affordable while offering adequate performance for most applications.
• Environmentally Friendly: Polypropylene is halogen-free, recyclable, and helps meet eco-friendly cable standards. It doesn’t release heavy metals or toxic residues.

Disadvantages of Polypropylene in the Electrical Industry

• Limited Temperature Resistance: Polypropylene can withstand long-term temperatures up to about 105–110°C. It’s unsuitable for high-temperature cables.
• Flammability: Though it produces less smoke and toxic gas than PVC, polypropylene is still combustible and cannot be used in fireproof cables.
• Moderate Tensile Strength: It’s not suitable as the main strength element in cables that experience high tensile loads (e.g., aerial or elevator cables).
• Creep and Deformation: Under long-term mechanical stress or near its softening temperature, polypropylene may deform slightly, affecting long-term cable integrity.

Future of Polypropylene in the Electrical Industry

• Expansion in Fiber Optic Networks: With the growth of digital communication infrastructure, demand for fiber optic and telecom cables is rising. Polypropylene’s use as a filler and non-conductive component will increase significantly in this sector.
• Advanced High-Voltage Cables: Modern HVDC cables are being designed using advanced polymeric insulation instead of traditional oil-paper systems. Modified polypropylene blends show promise as dry-type insulation materials for these cables, potentially creating a new market segment.
• Improved Flame-Retardant Grades: Research continues into halogen-free flame-retardant additives for polypropylene that enhance fire resistance without compromising electrical properties. Future versions may feature self-extinguishing behavior for improved cable safety.

The use of polypropylene in the electrical industry highlights the critical yet often overlooked role this material plays in ensuring safe and durable electrical systems. From everyday power cables to high-performance fiber optic networks, polypropylene enhances quality and reliability. As its properties continue to improve, this versatile and insulating polymer will remain a cornerstone of modern cable engineering and electrical manufacturing.