by Copper is one of the most commonly used materials for automotive wiring and cables. It is a very good conductor of electricity which makes it ideal for carrying electrical current throughout the vehicle. Some key advantages of using copper include its high conductivity, corrosion resistance, and versatility. Due to its conductivity being over 60% better than aluminium, copper cables can carry higher amperage loads through smaller cross-sectional areas which allows for lighter and more compact wiring harnesses. Its corrosion resistance properties also make copper wiring durable in the wide range of temperatures, pressures, and harsh environmental conditions found within modern vehicles.
Aluminium
While copper remains the dominant material, aluminium usage has been growing in the automotive industry due to its lighter weight. Automotive Wire And Cable Materials Aluminium conducts electricity almost as efficiently as copper, at about 60% of copper’s conductivity. However, it is significantly lighter with a density of about 30% of copper. The reduced weight translates into improved fuel efficiency for vehicles. Aluminium also offers benefits like lower material and installation costs compared to copper. However, it requires special consideration to ensure proper terminations and avoidance of corrosion at connector interfaces. Proper coating, shaping, and joining techniques must be used to compensate for its lesser conductivity.
Tin-Coated Copper
Many newer vehicles now use tin-coated copper wires rather than plain copper. The tin coating protects the copper from corrosion, particularly from harsh chemicals like automotive coolant. It also improves solderability which helps ensure secure connections. The tin layer is extremely thin, usually only a few micrometres thick, so it does not diminish copper’s conductivity. Tin-coated copper combines copper’s electrical properties with added protection against corrosion for longer service life. It is commonly used for battery cables, wiring harness cables, and other critical conductive paths.
Cross-Linked Polyethylene
Cross-linked polyethylene (XLPE) is a popular automotive wires and cables material used to protect wiring and cable cores. It offers benefits like high dielectric strength, flexibility, resistance to heat and moisture, low-temperature performance, and durability. XLPE maintains its insulating properties over a wide temperature range from -50°C to 150°C. Its cross-linked molecular structure makes it especially durable and resistant to abrasion, cuts, and chemical exposure compared to other plastics. These characteristics allow it to serve effectively as wire and cable insulation even in harsh under-hood environments. XLPE is most often used for insulation of low to medium voltage automotive harnesses and cables.
Fluoropolymers
For applications requiring maximum insulation performance, especially in high temperature locations, fluoropolymers like FEP, PFA and PTFE are used. They can withstand continuous temperatures up to 250°C with short term temperature exposures as high as 300°C. This makes them well-suited for use near engine parts. They also offer excellent chemical resistance, high dielectric strength, and flexibility. Some disadvantages include their higher cost compared to other insulators as well as more complex processing requirements. However, their unique high temperature and chemical resistance properties enable important under-hood applications where other plastics could not survive.
Automotive Cable Shielding
Foil Shielding
Foil shielding, usually made from aluminum foil, provides effective electromagnetic interference (EMI) and radio frequency interference (RFI) protection for wiring harnesses and cables. It functions by enclosing conductive foil around the cable which directs interfering electromagnetic fields around the cable. The foil must have a minimum of 35% overlapping coverage to maintain conductivity. It is commonly used in applications like data communication cables where noise protection is critical. Due to its light weight and flexibility, foil shielding is well-suited for automotive cable designs.
Braided Shielding for Automotive Wires and Cables Materials
Braided shielding forms a tubular braided wire mesh over the cable insulating jacket. It provides superior shielding effectiveness compared to foil by enclosing the cable with 360° coverage. The individual wire strands maintain electrical contact even when bent. Common materials used are tinned copper, silver-plated copper, or aluminum-coated steel wires. Tinned copper braids offer the best shielding but at a higher cost. Braided shielding is able to withstand the more demanding vibration and flexing stresses inside vehicles while still maintaining its EMI protection capabilities. It is widely adopted for shielding important cables like main battery cables.
Jacketed Cables
Once the insulated conductors and protective screening layer are assembled, a further outer protective jacket made from thermoplastic materials is often applied. Commonly used jacket materials include polyvinyl chloride (PVC), cross-linked polyethylene (XLPE) and polyurethane (PUR). The outer jacket protects the inner components from damage, abrasion, cuts, moisture intrusion and other environmental stresses. It also serves to hold the assembled cable together. Automotive cable jackets are formulated with properties like heat resistance, low-temperature performance, oil and chemical resistance, abrasion resistance and flexibility.
Continuous Advances
The automotive wires and cables materials industry continues innovating new materials and designs to meet the evolving needs of the highly engineered vehicles of today and future. Advancements aim to achieve the goals of improved electrical performance, lighter weight, greater reliability under harsh conditions, ease of installation, and reduced costs. New conductor alloys, insulation formulations, shielding methods and jacketing solutions help ensure wiring harnesses and cables can reliably power, communicate and control increasingly sophisticated vehicle systems and technologies for many miles to come.
*Note:
1. Source: Coherent Market Insights, Public sources, Desk research
2. We have leveraged AI tools to mine information and compile it.
