5 Common Types of Wiring Harness Materials

You have plenty of choices in wiring harness materials for jacketing. You need to see what features you need to pick and what to leave to make it suitable for your job. Sometimes, you may not get desired properties from a single material. In such cases, it is better to go for composite insulations. Two or more materials combine to suit a particular application in composite insulations. However, sometimes, a composite with desired properties may not be economically viable and commercially feasible. This blog will help you choose a proper one.

Wiring harness Materials Understanding

Every electrical wiring harness needs a coating material. 

The coating on wires helps resist electrical leakage and prevents the wire’s electric current from contacting other conductors. It also plays a crucial role in protecting against environmental threats like water, heat, mechanical moisture and chemical issues, thus preserving the material integrity of the wire. 

A cable comprises different layers of coating materials. And the outer covering or the first line of defense is the jacket. A cable jacket does not contribute to its electrical performance. It mainly protects the insulation and conductor from physical stresses, and it acts as a moisture barrier and offers protection to the cable against flame and chemicals. Also, the jacket minimizes physical damage during and after installing a cable.

Caption: Tell cable jacket from wire insulation/jacket

Plastic, Rubber, vs Fluoropolymers

The most common wire coating materials are plastic, rubber, and fluoropolymers.

• Plastics are common wire-coating materials for durability, flexibility, electrical conductivity, fire resistance and excellent UV resistance.
• One thing that differentiates rubber from plastic is flexibility at low temperatures. Rubber insulators are also resistant to high heat and moisture without breaking down.
• Working in high-temperature and severe chemical conditions, Fluoropolymers are resistant to bases, acids, and solvents. They can also be used as cable insulators due to their exceptional electric-resistant qualities.

Thermoplastic materials vs thermoset materials 

At high temperatures, thermoplastic materials are malleable and can melt, allowing the material to take on some toughness and flexibility once compounded. It is also cost-effective, though there is the risk of weakening and dissolving when heated at high temperatures.

On the other hand, thermosets don’t soften after passing through high temperatures, giving them an advantage over thermoplastics, which means the material retains its “rubbery” consistency and original qualities even when heated.

Wire Coating Application

Many wire coating types are available to suit different protection levels, so it’s important to consider the jacket type for their applications, collectors, and environments.

Properties	Suits which industrial applications
Tough, tear and abrasion resistance	Applications that require high mechanical stresses
Cable flexibility at low temperatures	Suitable for use in winters and arctic climates
Stability at a wide range of temperatures	Increased thermal performance suits various applications
Resistance to heat	Applications requiring long life expectancy
Resistance to deformation	Applications that require cables in tight spaces
Flame and oil resistance	Prevents spread of fire and offers workers safety in different applications
Low moisture absorption	Suitable for humid environments and gives long life
Weather and UV resistance	Applications that require UV exposure
Chemical resistance	Increase life expectancy of cable during harmful chemical exposure

5 Types of Wiring Harnesses Materials

There are mainly 5 types of materials commonly used in wiring harnesses.

1. Polyvinyl Chloride (PVC)

PVC is one of the most flexible and versatile thermoplastics due to its fantastic flexibility. It has a wide range of electric cable manufacturing applications as bedding, insulation, and sheathing material.

PVC wiring harnesses benefits

• The processing of PVC is easy, so it was more accessible than rubber;
• The cost of PVC is less than many other wire insulation materials;
•  It is also recyclable;
•  PVC offers an excellent lifespan;The original properties make it rigid and challenging, but it is usable in many applications after easy modifications.
• The use of PVC for wire insulation in wiring harnesses allows the harnesses to perform effectively despite the temperature rise.

Applications of PVC wiring harnesses

In many wires and cables, you will find PVC as the primary insulation material. Wiringo is capable of offering wires or cables made of pvc and modified one for wiring harness design, according to the requirements of the client. Here are some significant examples of PVC in wiring harness:

• As jacketing and insulation for low voltage wire harness 
• For local telecommunication cable assemblies
• In wiring harnesses for automotive.
• Flexible wiring harnesses for better protection against tearing

2. Fluorinated Ethylene-Propylene (FEP)

FEP is the blend of hexafluoropropylene and tetrafluoroethylene. It has countless applications in industrial machinery as insulation and jacketing material for wires and cables.

FEP wiring harnesses benefits

• FEP offers great resistance to temperature ranges  of -80℃ to 200℃, without losing flexibility. 
• It is also durable with  excellent electrical insulation properties and chemical resistance. 
• FEP can withstand all weather conditions with effective water resistance properties.

Applications of FEP in wiring harness

• Military installation and military-grade equipment
• Oil and gas units where chemical exposure is a common problem
• Chemical industries with harsh work settings
• Medical facilities that need sterilization of wires
• Aviation and aerospace sector
• Cars and vehicle manufacturing units

3. Polyethylene (PE)

It is a disaster and harder plastic than PVC, as an electrically insulating material, available in thermoplastic and thermoset versions. 

In the original form, Polyethylene may not be suitable for wires where you need flexibility. But with some further modifications of additives and fillers, you can make it flexible according to the project specifications. Here are different types of PE:

• Low-density PE
• Linear low-density PE
• Medium-density PE
• High-density PE
• Chlorinated PE
• Cross linkable PE

Polyethylene wiring harness benefits

• Two versions option; Thermoset CPE is the cross-linked version of CPE. This polymer is suitable for cable jacket applications due to its excellent physical properties. This cross-linked polymer shows resistance against UV exposure, ozone, and prolonged water immersion. Also, it has high resistance to alkalis, acids, and solvents, suitable for the chemical processing industry. The thermoplastic version has excellent heat, flame, weather, oil, and oxidation resistance.  

• The original chemical properties of Polyethylene make it a tough and solid material. So it is rigid but offers better resistance against abrasion. 
• With resistance against different levels of temperature, from freezing conditions to boiling applications, Polyethylene can withstand extremes.
• Polyethene insulation is the perfect choice to minimize power loss with strong electrical properties. 
• Polyethene is originally lightweight and moisture-resistant, which makes it a suitable coating material for high-frequency signal carrying wires and transmission lines.

Applications of Polyethylene wiring harness

• Leakage of current or data from wires with Polyethylene coating is almost negligible. You will get a maximum efficient current supply from low or high voltage current-carrying wires.
•  For all the appliances that involve audio data and radio frequencies, wiring harnesses with Polyethylene offer better protection than other typical coating materials.

4. Nylon

Nylon is a common plastic wire-coating material for flexibility, electrical conductivity, fire resistance and excellent UV resistance. Despite having poor electrical properties and water resistance, it is used in wire harnesses because of its durability in harsh environments.

Nylon wiring harness benefits

• Highly flexible and soft material that is perfect for insulation.
• It has a string of abrasion resistance properties.
• Provides better protection against tearing and cut through.
• The chemical resistance makes it excellent insulation for industrial projects, too.
• Nylon is a lower cost option than other materials.  

Applications of Nylon wiring harness

• Nylon is highly flexible and adjustable according to the project specifications and harness layout. It is popular for some industries like automotive and aerospace industries. 
• When many bending and mechanical movements are involved, custom wiring harnesses with Nylon insulation can perform better.

5. Thermoplastic Rubber (TPR)

Several types of rubber are used for wire insulation, including:

• Thermoplastic rubber: TPR is a tough rubber and plasticizer blend that withstands various temperatures,  UV radiation, high temperatures, bad weather, and aging.
• Ethylene propylene rubber: EPR is an excellent insulator, resistant to heat, oxidation, water acids, and electrical currents. It is a synthetic elastomer with superior thermal properties and a more compact cross-section. You can use this wire coating material in high-voltage applications with temperatures in the -50℃ to 160℃ range.
• Neoprene: Its electrical conductivity is better, and it exhibits superior abrasion resistance than other polymers, appealing to harsh and severe environments.
• Silicone: This rubber has remained an excellent option for environments where temperatures exceed 150℃. They exhibit high flexibility and exceptional flame retardance, with a heat resistance of up to 180℃. As a multipurpose electrical insulator, silicone rubber is highly elastic and fits any appliance wire.
• Fiberglass: With fiberglass, you have a material that can withstand extremely high temperatures, up to 480℃,  making it perfect for such applications as mining, energy, military, and oil sectors. Also, fiberglass has excellent resistance properties against chemicals and water.

Among them, thermoplastic rubber is the primary focus of custom automotive wiring harness manufacturers. 

Properties of Thermoplastic Rubber

• Higher processing speed leads to faster production.
• Temperature resistance against extreme temperature levels
• Excellent resistance against environmental factors and heat
• Enhanced lifespan

Choose Wiringo for High-Performance Wire Harnesses

Selecting an insulating or jacketing material for wiring harness is critical for its successful use in any application. Before picking any jacketing material, you need to consider certain factors such as temperature, fire resistance, UV resistance, flexibility, durability, chemical resistance, etc. 
We are a leading manufacturer of wiring harnesses and cable assemblies. We can assist you if you are confused about so many jackets’ material choices.